IL-6 inhibitors — MCQs

10 questions

A 65-year-old patient presents with acute left lower quadrant abdominal pain and is diagnosed with diverticulitis. Which of the following is most likely to have prevented this patient's condition?

A 28-year-old woman has a follow-up visit with her physician. She was diagnosed with allergic rhinitis and bronchial asthma at 11 years of age. Her regular controller medications include daily high-dose inhaled corticosteroids and montelukast, but she still needs to use a rescue inhaler 3–4 times a week following exercise. She also becomes breathless with moderate exertion. After a thorough evaluation, the physician explains that her medication dosages need to be increased. She declines taking oral corticosteroids daily due to concerns about side effects. The physician prescribes omalizumab, which is administered subcutaneously every 3 weeks. Which of the following best explains the mechanism of action of the new medication that has been added to the controller medications?

A 47-year-old woman presents to the physician with complaints of fatigue accompanied by symmetric pain, swelling, and stiffness in her wrists, fingers, knees, and other joints. She describes the stiffness as being particularly severe upon awakening, but gradually improves as she moves throughout her day. Her physician initially suggests that she take NSAIDs. However, after a few months of minimal symptomatic improvement, she is prescribed an immunosuppressive drug that has a mechanism of preventing IL-2 transcription. What is the main toxicity that the patient must be aware of with this particular class of drugs?

A 52-year-old man presents to the office for a regular health checkup. He was diagnosed with type 2 diabetes mellitus 6 years ago and has been taking metformin alone. Over the past year, his daily blood glucose measurements have gradually been increasing. During his previous visit, his HbA1c level was 7.9% and the doctor mentioned the possibility of requiring an additional medication to keep his blood sugar under better control. Today, his HbA1c is 9%. The doctor mentions a research article that has been conducted on a randomized and controlled group of 200 subjects studying a new anti-diabetic medication. It has been shown to significantly reduce glucose levels and HbA1c levels compared to the current gold standard treatment. Possible adverse effects, however, are still being studied, though the authors believe that they will be minimal. In this study, what would most likely increase the chances of detecting a significant adverse effect?

A 32-year-old woman comes to the physician because of pain and stiffness in both of her hands for the past 3 weeks. The pain is most severe early in the day and does not respond to ibuprofen. She has no history of serious illness and takes no medications. Vital signs are within normal limits. Examination shows swelling and tenderness of the wrists and metacarpophalangeal joints bilaterally. Range of motion is decreased due to pain. There are subcutaneous, nontender, firm, mobile nodules on the extensor surface of the forearm. Which of the following is the most appropriate pharmacotherapy for this patient's current symptoms?

A 64-year-old woman comes to the physician because of a 7-month history of abdominal discomfort, fatigue, and a 6.8-kg (15-lb) weight loss. Physical examination shows generalized pallor and splenomegaly. Laboratory studies show anemia with pronounced leukocytosis and thrombocytosis. Cytogenetic analysis shows a BCR-ABL fusion gene. A drug with which of the following mechanisms of action is most appropriate for this patient?

A 34-year-old man with a 2-year history of rheumatoid arthritis is being evaluated on a follow-up visit. He is currently on methotrexate and celecoxib for pain management and has shown a good response until now. However, on this visit, he mentions that the morning stiffness has been getting progressively worse. On physical examination, both his wrists are erythematous and swollen, nodules on his elbows are also noted. Rheumatoid factor is 30 (normal reference values: < 15 IU/mL), ESR is 50 mm/h, anti-citrullinated protein antibodies is 55 (normal reference values: < 20). What is the next best step in the management of this patient?

A 66-year-old man comes to the physician because of a 3-month history of constipation and streaks of blood in his stool. He has had a 10-kg (22-lb) weight loss during this period. Colonoscopy shows an exophytic tumor in the sigmoid colon. A CT scan of the abdomen shows liver metastases and enlarged mesenteric and para-aortic lymph nodes. A diagnosis of stage IV colorectal cancer is made, and palliative chemotherapy is initiated. The chemotherapy regimen includes a monoclonal antibody that inhibits tumor growth by preventing ligand binding to a protein directly responsible for epithelial cell proliferation and organogenesis. Which of the following proteins is most likely inhibited by this drug?

A 67-year-old woman is admitted to the hospital because of a 2-day history of fever, headache, jaw pain, and decreased vision in the right eye. Her erythrocyte sedimentation rate is 84 mm per hour. Treatment with methylprednisolone is initiated but her symptoms do not improve. The physician recommends the administration of a new drug. Three days after treatment with the new drug is started, visual acuity in the right eye increases. The beneficial effect of this drug is most likely due to inhibition of which of the following molecules?

Q10

A 63-year-old HIV-positive man comes to the physician for a routine health maintenance examination. Four years ago, he was diagnosed with HIV and was started on cART therapy. He tells the physician that he has been having difficulty adhering to his medication regimen. He has been unemployed for the past couple of years and relies on unemployment benefits to cover the costs of daily living. His father died of lymphoma at the age of 60 years. He wants more information about his risk of developing DLBCL. Which of the following is the greatest risk factor for the development of DLBCL in HIV-positive patients?

IL-6 inhibitors US Medical PG Practice Questions and MCQs

Question 1: A 65-year-old patient presents with acute left lower quadrant abdominal pain and is diagnosed with diverticulitis. Which of the following is most likely to have prevented this patient's condition?

A. Anticoagulation with warfarin
B. High-fiber diet (Correct Answer)
C. Different antibiotic regimen for bronchitis
D. Sitz baths and nifedipine suppositories
E. Long-term use of aspirin

Explanation: ***High-fiber diet*** - A **high-fiber diet** increases stool bulk and reduces intracolonic pressure, thereby preventing the formation of **diverticula** and reducing the risk of diverticulitis. - It helps maintain **regular bowel movements** and minimizes straining, which are key in preventing diverticular disease. *Anticoagulation with warfarin* - **Warfarin** is an anticoagulant used to prevent blood clots; it has no direct impact on the formation of **diverticula** or the prevention of diverticulitis. - While bleeding is a potential complication of diverticular disease, anticoagulation would generally *increase* the risk of bleeding, not prevent the condition itself. *Different antibiotic regimen for bronchitis* - Antibiotics treat **bacterial infections** and are irrelevant in the prevention of diverticulitis, which primarily relates to dietary and colonic pressure issues. - Changing an antibiotic regimen for an unrelated respiratory infection like bronchitis would not affect the risk factors for **diverticular disease**. *Sitz baths and nifedipine suppositories* - **Sitz baths** and **nifedipine suppositories** are treatments for anorectal conditions like **hemorrhoids** or **anal fissures** and do not influence the development of diverticulitis. - These interventions target symptoms in the anal region and have no physiological connection to the colon's diverticular disease processes. *Long-term use of aspirin* - **Aspirin** is an anti-inflammatory and antiplatelet agent used for pain relief and cardiovascular protection; it does not prevent the formation of **diverticula** or diverticulitis. - Non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin can actually **increase the risk of diverticular complications**, such as bleeding or perforation, rather than prevent the disease.

Question 2: A 28-year-old woman has a follow-up visit with her physician. She was diagnosed with allergic rhinitis and bronchial asthma at 11 years of age. Her regular controller medications include daily high-dose inhaled corticosteroids and montelukast, but she still needs to use a rescue inhaler 3–4 times a week following exercise. She also becomes breathless with moderate exertion. After a thorough evaluation, the physician explains that her medication dosages need to be increased. She declines taking oral corticosteroids daily due to concerns about side effects. The physician prescribes omalizumab, which is administered subcutaneously every 3 weeks. Which of the following best explains the mechanism of action of the new medication that has been added to the controller medications?

A. Prevention of binding of IgE antibodies to mast cell receptors (Correct Answer)
B. Inhibition of synthesis of interleukin-4 (IL-4)
C. Inhibition of synthesis of IgE antibodies
D. Selective binding to interleukin-3 (IL-3) and inhibition of its actions
E. Prevention of binding of interleukin-5 (IL-5) to its receptors

Explanation: ***Prevention of binding of IgE antibodies to mast cell receptors*** - **Omalizumab** is a **monoclonal antibody** that specifically targets and binds to **free IgE** in the bloodstream, preventing it from attaching to high-affinity IgE receptors on **mast cells** and **basophils**. - By reducing surface IgE, omalizumab **downregulates IgE receptors** on these cells, thereby reducing the release of inflammatory mediators upon allergen exposure, which is beneficial in **allergic asthma** uncontrolled by standard therapies. *Inhibition of synthesis of interleukin-4 (IL-4)* - **IL-4** is a cytokine primarily involved in **Th2 differentiation** and **IgE class switching**, but omalizumab's action is not directly blocking its synthesis. - While *omalizumab* indirectly reduces IgE levels, its primary mechanism isn't to inhibit the production of IL-4 itself, but rather to prevent the effects of existing IgE. *Inhibition of synthesis of IgE antibodies* - **Omalizumab** does not inhibit the *synthesis* of IgE antibodies; instead, it binds to already synthesized **free IgE** circulating in the blood. - This binding effectively neutralizes IgE, preventing it from contributing to the allergic cascade, but it doesn't stop B cells from producing more IgE. *Selective binding to interleukin-3 (IL-3) and inhibition of its actions* - **IL-3** is a cytokine involved in the growth and differentiation of various **hematopoietic cells**, including mast cells and basophils, but it is not the target of omalizumab. - Omalizumab specifically targets **IgE** and has no known direct action on IL-3 signaling pathways. *Prevention of binding of interleukin-5 (IL-5) to its receptors* - **IL-5** is a key cytokine in the **eosinophilic inflammatory pathway** and is targeted by other therapies (e.g., mepolizumab, reslizumab) used for severe eosinophilic asthma. - Omalizumab's mechanism is distinct, focusing on **IgE-mediated inflammation** rather than direct eosinophil control.

Question 3: A 47-year-old woman presents to the physician with complaints of fatigue accompanied by symmetric pain, swelling, and stiffness in her wrists, fingers, knees, and other joints. She describes the stiffness as being particularly severe upon awakening, but gradually improves as she moves throughout her day. Her physician initially suggests that she take NSAIDs. However, after a few months of minimal symptomatic improvement, she is prescribed an immunosuppressive drug that has a mechanism of preventing IL-2 transcription. What is the main toxicity that the patient must be aware of with this particular class of drugs?

A. Pancytopenia
B. Osteoporosis
C. Hepatotoxicity
D. Nephrotoxicity (Correct Answer)
E. Hyperglycemia

Explanation: ***Nephrotoxicity*** - The drug described, which prevents **IL-2 transcription**, is likely a **calcineurin inhibitor** like cyclosporine or tacrolimus, often used in autoimmune diseases. - **Nephrotoxicity** (kidney damage) is a major dose-limiting toxicity of calcineurin inhibitors, causing both acute and chronic kidney injury. *Pancytopenia* - While some immunosuppressants can cause **pancytopenia** (e.g., azathioprine, methotrexate), it is not the classic or primary toxicity associated with calcineurin inhibitors. - Calcineurin inhibitors primarily affect **renal function** and can cause other side effects like hypertension or neurotoxicity. *Osteoporosis* - **Osteoporosis** is a known side effect of long-term glucocorticoid use, but not typically a primary toxicity of calcineurin inhibitors. - Glucocorticoids reduce bone formation and increase bone resorption, leading to bone density loss. *Hepatotoxicity* - **Hepatotoxicity** (liver damage) can occur with various immunosuppressants, such as methotrexate, but it is not the most prominent or defining toxicity for calcineurin inhibitors. - While cyclosporine can cause some liver enzyme elevation, **nephrotoxicity** is far more common and severe. *Hyperglycemia* - **Hyperglycemia** can be a side effect of some immunosuppressants, particularly **glucocorticoids** and **tacrolimus** (another calcineurin inhibitor). - However, for the class of drugs that prevent IL-2 transcription (calcineurin inhibitors), **nephrotoxicity** remains the most significant and common major toxicity to be aware of.

Question 4: A 52-year-old man presents to the office for a regular health checkup. He was diagnosed with type 2 diabetes mellitus 6 years ago and has been taking metformin alone. Over the past year, his daily blood glucose measurements have gradually been increasing. During his previous visit, his HbA1c level was 7.9% and the doctor mentioned the possibility of requiring an additional medication to keep his blood sugar under better control. Today, his HbA1c is 9%. The doctor mentions a research article that has been conducted on a randomized and controlled group of 200 subjects studying a new anti-diabetic medication. It has been shown to significantly reduce glucose levels and HbA1c levels compared to the current gold standard treatment. Possible adverse effects, however, are still being studied, though the authors believe that they will be minimal. In this study, what would most likely increase the chances of detecting a significant adverse effect?

A. Decreasing post-market surveillance time
B. Non-randomization
C. Decreasing sample size
D. Increasing selection bias
E. Increasing sample size (Correct Answer)

Explanation: ***Increasing sample size*** - A **larger sample size** increases the **statistical power** of a study, making it more likely to detect a real difference or effect, including rare adverse events. - With more participants, there's a higher chance of observing adverse effects that might only occur in a small percentage of individuals. *Decreasing post-market surveillance time* - **Post-market surveillance** occurs *after* a drug is approved and involves monitoring thousands, or even millions, of patients for adverse events. - **Decreasing** this time would *reduce* the likelihood of detecting rare or long-term adverse effects, as the exposure period and number of observed patients would be smaller. *Non-randomization* - **Non-randomization** can introduce **confounding variables** and **bias**, making it difficult to attribute observed effects solely to the medication. - While it might reveal an association, it doesn't necessarily strengthen the ability to precisely identify significant adverse effects versus other contributing factors. *Decreasing sample size* - A **smaller sample size** reduces the **statistical power** of a study, making it less likely to detect a true difference or effect, especially for uncommon adverse events. - Rare adverse effects are less likely to be observed in a small group of participants. *Increasing selection bias* - **Selection bias** occurs when the study participants are not representative of the general population or when groups are not comparable, leading to skewed results. - This bias can *obscure* or *misrepresent* the true incidence of adverse effects, making accurate detection more difficult, rather than increasing it.

Question 5: A 32-year-old woman comes to the physician because of pain and stiffness in both of her hands for the past 3 weeks. The pain is most severe early in the day and does not respond to ibuprofen. She has no history of serious illness and takes no medications. Vital signs are within normal limits. Examination shows swelling and tenderness of the wrists and metacarpophalangeal joints bilaterally. Range of motion is decreased due to pain. There are subcutaneous, nontender, firm, mobile nodules on the extensor surface of the forearm. Which of the following is the most appropriate pharmacotherapy for this patient's current symptoms?

A. Adalimumab
B. Prednisone (Correct Answer)
C. Methotrexate
D. Colchicine
E. Sulfasalazine

Explanation: ***Prednisone*** - The patient presents with **symmetrical polyarthritis** of the small joints, morning stiffness unresponsive to NSAIDs, and **rheumatoid nodules**, which are classic features of **rheumatoid arthritis (RA)**. - For **immediate symptom control** of acute RA flares, **glucocorticoids** like prednisone are highly effective in rapidly reducing inflammation and pain. - In clinical practice, prednisone would be used as **bridge therapy** while initiating disease-modifying therapy, providing symptomatic relief within days. *Methotrexate* - Methotrexate is a **disease-modifying antirheumatic drug (DMARD)** and is the **first-line agent for long-term RA management** per current guidelines. - While this should be initiated promptly in newly diagnosed RA, it has a **slow onset of action (6-12 weeks)** and would not provide immediate relief for the patient's current severe symptoms. - In practice, methotrexate would be started concurrently with a short course of glucocorticoids. *Adalimumab* - Adalimumab is a **TNF-alpha inhibitor**, a **biologic DMARD**, used for moderate to severe RA, typically when conventional DMARDs are insufficient. - It is **not first-line therapy** for newly diagnosed RA and requires prior screening for latent infections due to **immunosuppression risk**. - Like methotrexate, it has a delayed onset of action and would not provide rapid symptom relief. *Colchicine* - Colchicine is primarily used for the treatment of **gout** and **pseudogout**, by inhibiting neutrophil migration and microtubule polymerization. - It is **not indicated** for the management of rheumatoid arthritis. *Sulfasalazine* - Sulfasalazine is a **conventional synthetic DMARD** used in the treatment of RA, particularly in mild to moderate cases or as combination therapy. - Like methotrexate, it has a **slow onset of action (weeks to months)** and is not appropriate for rapid symptom control in an acute presentation.

Question 6: A 64-year-old woman comes to the physician because of a 7-month history of abdominal discomfort, fatigue, and a 6.8-kg (15-lb) weight loss. Physical examination shows generalized pallor and splenomegaly. Laboratory studies show anemia with pronounced leukocytosis and thrombocytosis. Cytogenetic analysis shows a BCR-ABL fusion gene. A drug with which of the following mechanisms of action is most appropriate for this patient?

A. Ribonucleotide reductase inhibitor
B. Monoclonal anti-HER-2 antibody
C. Topoisomerase II inhibitor
D. Monoclonal anti-CD20 antibody
E. Tyrosine kinase inhibitor (Correct Answer)

Explanation: ***Tyrosine kinase inhibitor*** - The patient's symptoms (abdominal discomfort, fatigue, weight loss, pallor, splenomegaly), laboratory findings (**anemia with pronounced leukocytosis and thrombocytosis**), and the presence of a **BCR-ABL fusion gene** are highly characteristic of **Chronic Myeloid Leukemia (CML)**. - The **BCR-ABL fusion gene** encodes a constitutively active **tyrosine kinase**, which is the hallmark of CML and the primary therapeutic target for **tyrosine kinase inhibitors (TKIs)** like imatinib. *Ribonucleotide reductase inhibitor* - **Ribonucleotide reductase inhibitors** (e.g., hydroxyurea) block DNA synthesis and are used in myeloproliferative disorders to reduce cell counts, but they are not specific to the **BCR-ABL fusion gene** and are not the most appropriate first-line targeted therapy for CML. - While they can control symptoms, they do not target the underlying molecular defect in CML as effectively as TKIs. *Monoclonal anti-HER-2 antibody* - **Monoclonal anti-HER-2 antibodies** (e.g., trastuzumab) are used to treat **HER-2 positive breast cancer** and some gastric cancers. - They are not relevant to the treatment of CML, which is characterized by the **BCR-ABL fusion gene**. *Topoisomerase II inhibitor* - **Topoisomerase II inhibitors** (e.g., etoposide, doxorubicin) prevent DNA unwinding and replication, leading to cell death, and are used in various hematologic malignancies and solid tumors. - These drugs are broad-spectrum chemotherapeutic agents not specifically targeted to the **BCR-ABL fusion protein** in CML and are not first-line therapy for this condition. *Monoclonal anti-CD20 antibody* - **Monoclonal anti-CD20 antibodies** (e.g., rituximab) target the CD20 protein on B lymphocytes and are primarily used to treat **B-cell non-Hodgkin lymphoma** and some autoimmune diseases. - They have no role in the direct treatment of CML, which is a myeloid malignancy.

Question 7: A 34-year-old man with a 2-year history of rheumatoid arthritis is being evaluated on a follow-up visit. He is currently on methotrexate and celecoxib for pain management and has shown a good response until now. However, on this visit, he mentions that the morning stiffness has been getting progressively worse. On physical examination, both his wrists are erythematous and swollen, nodules on his elbows are also noted. Rheumatoid factor is 30 (normal reference values: < 15 IU/mL), ESR is 50 mm/h, anti-citrullinated protein antibodies is 55 (normal reference values: < 20). What is the next best step in the management of this patient?

A. Sulfasalazine
B. Adalimumab monotherapy
C. Methotrexate and Corticosteroids
D. Methotrexate and Infliximab (Correct Answer)
E. Infliximab monotherapy

Explanation: **Methotrexate and Infliximab** - The patient is experiencing a **flare-up of rheumatoid arthritis** despite being on methotrexate, indicated by worsening morning stiffness, active synovitis (erythematous and swollen wrists), elevated ESR, and positive rheumatoid factor and anti-CCP. This suggests a need for more aggressive therapy, and adding a **biologic agent like infliximab (an anti-TNF agent)** to methotrexate is a standard approach for moderate to severe RA that is not adequately controlled by methotrexate monotherapy. - Combination therapy with **methotrexate and a biologic DMARD** (e.g., TNF inhibitors like infliximab) has been shown to be more effective than monotherapy for controlling disease activity and preventing joint damage in refractory RA. *Sulfasalazine* - **Sulfasalazine** is a conventional synthetic DMARD that is generally used as a **first-line agent or in combination therapy** for mild to moderate RA. - Given the patient's ongoing active disease despite methotrexate and the severity of his symptoms, sulfasalazine is unlikely to be sufficient to achieve disease control. *Adalimumab monotherapy* - While adalimumab (another anti-TNF biologic) is an effective treatment for RA, **biologic monotherapy is generally less effective** than combination therapy with methotrexate. - Current guidelines and clinical practice favor combining biologic DMARDs with methotrexate for optimal outcomes in RA management, especially in patients with active disease. *Methotrexate and Corticosteroids* - **Corticosteroids** are effective in rapidly reducing inflammation and can be used for **short-term management of RA flares**. - However, corticosteroids are not recommended for long-term use due to significant side effects and do not address the underlying disease progression as comprehensively as biologic DMARDs in patients refractory to methotrexate. *Infliximab monotherapy* - Similar to adalimumab monotherapy, **infliximab is typically more effective when combined with methotrexate**. - Using infliximab alone would be a less optimal choice for this patient whose disease is clearly not controlled by methotrexate, as it may lead to a suboptimal response and potentially increase the risk of developing anti-drug antibodies.

Question 8: A 66-year-old man comes to the physician because of a 3-month history of constipation and streaks of blood in his stool. He has had a 10-kg (22-lb) weight loss during this period. Colonoscopy shows an exophytic tumor in the sigmoid colon. A CT scan of the abdomen shows liver metastases and enlarged mesenteric and para-aortic lymph nodes. A diagnosis of stage IV colorectal cancer is made, and palliative chemotherapy is initiated. The chemotherapy regimen includes a monoclonal antibody that inhibits tumor growth by preventing ligand binding to a protein directly responsible for epithelial cell proliferation and organogenesis. Which of the following proteins is most likely inhibited by this drug?

A. VEGF
B. TNF-α
C. EGFR (Correct Answer)
D. ALK
E. CD52

Explanation: ***EGFR*** - The description of a monoclonal antibody preventing ligand binding to a protein responsible for **epithelial cell proliferation** and organogenesis strongly points to the **epidermal growth factor receptor (EGFR)**. - EGFR is highly expressed in many colorectal cancers and its activation by ligands like EGF promotes cell growth, survival, and metastasis. Inhibiting it reduces tumor progression. *VEGF* - **Vascular endothelial growth factor (VEGF)** is primarily involved in **angiogenesis**, the formation of new blood vessels. - While anti-VEGF therapies (e.g., bevacizumab) are used in colorectal cancer, their mechanism is inhibiting blood supply to the tumor, not directly blocking a receptor responsible for epithelial cell proliferation as described. *TNF-α* - **Tumor necrosis factor-alpha (TNF-α)** is a **cytokine** primarily involved in inflammation and immune responses. - Antibodies against TNF-α (e.g., infliximab) are used in inflammatory conditions like Crohn's disease, not typically as targeted therapy for colorectal cancer directly inhibiting epithelial proliferation. *ALK* - **Anaplastic lymphoma kinase (ALK)** is a **receptor tyrosine kinase** often implicated in lung cancer and lymphomas. - ALK rearrangements lead to oncogenic fusion proteins, but it is not a primary target for widespread epithelial cell proliferation in colorectal cancer. *CD52* - **CD52** is a glycoprotein found on the surface of various immune cells, including lymphocytes. - Antibodies targeting CD52 (e.g., alemtuzumab) are used in certain leukemias and lymphomas to deplete these cells, not for inhibiting epithelial cell proliferation in solid tumors.

Question 9: A 67-year-old woman is admitted to the hospital because of a 2-day history of fever, headache, jaw pain, and decreased vision in the right eye. Her erythrocyte sedimentation rate is 84 mm per hour. Treatment with methylprednisolone is initiated but her symptoms do not improve. The physician recommends the administration of a new drug. Three days after treatment with the new drug is started, visual acuity in the right eye increases. The beneficial effect of this drug is most likely due to inhibition of which of the following molecules?

A. Leukotriene D4
B. Interleukin-4
C. Complement component 5
D. Interleukin-6 (Correct Answer)
E. Thromboxane A2

Explanation: ***Interleukin-6*** - The patient's symptoms (fever, headache, jaw pain, decreased vision, elevated ESR) are classic for **giant cell arteritis (GCA)**. GCA involves transmural inflammation of medium to large arteries, often affecting the temporal artery and ophthalmic artery. - **Tocilizumab**, a monoclonal antibody that targets the **IL-6 receptor**, is an approved treatment for GCA, especially in cases unresponsive to corticosteroids or for steroid-sparing effects. Its efficacy in improving vision and reducing inflammation supports its action on IL-6. *Leukotriene D4* - **Leukotriene D4** is a potent bronchoconstrictor and mediator in allergic and asthmatic responses. - Inhibitors of leukotriene D4, such as montelukast, are used to treat **asthma** and **allergic rhinitis**, not vasculitis like GCA. *Interleukin-4* - **Interleukin-4** is a key cytokine in the **Th2 immune response**, promoting B-cell activation, **IgE production**, and allergic inflammation. - Drugs targeting IL-4 (or its receptor) are used in conditions like **atopic dermatitis** and **asthma**, not GCA, which is primarily a Th1-mediated inflammatory disease. *Complement component 5* - **Complement component 5 (C5)** is a central molecule in the **complement cascade**, playing a role in inflammation and cell lysis. - While the complement system can be involved in various inflammatory conditions, specific C5 inhibition is primarily seen with drugs like **Eculizumab** for paroxysmal nocturnal hemoglobinuria or atypical hemolytic uremic syndrome, which are distinct from GCA. *Thromboxane A2* - **Thromboxane A2** is a potent vasoconstrictor and platelet aggregator, primarily produced by platelets. - Its inhibition, typically by **aspirin**, is used for **antiplatelet effects** in cardiovascular disease and stroke prevention, not for the direct treatment of large vessel vasculitis or to rapidly resolve visual loss in GCA.

Question 10: A 63-year-old HIV-positive man comes to the physician for a routine health maintenance examination. Four years ago, he was diagnosed with HIV and was started on cART therapy. He tells the physician that he has been having difficulty adhering to his medication regimen. He has been unemployed for the past couple of years and relies on unemployment benefits to cover the costs of daily living. His father died of lymphoma at the age of 60 years. He wants more information about his risk of developing DLBCL. Which of the following is the greatest risk factor for the development of DLBCL in HIV-positive patients?

A. Poor adherence to cART (Correct Answer)
B. Income below $30,000 per year
C. Male sex
D. Positive family history of cancer
E. Age over 55 years

Explanation: **Poor adherence to cART** - **Poor adherence** to cART leads to **uncontrolled HIV replication** and persistent **immunosuppression**, which significantly increases the risk of developing **DLBCL**. - **Immune dysregulation** caused by HIV directly contributes to a higher incidence of **AIDS-defining malignancies**, including DLBCL. *Income below $30,000 per year* - While **socioeconomic factors** can impact access to care and medication adherence, low income itself is not a direct biological risk factor for DLBCL. - Its influence is secondary to its effect on adherence and overall health status, rather than a primary risk factor for the malignancy. *Positive family history of cancer* - Although a family history of cancer can increase the risk for some malignancies, it is generally **not a significant risk factor** for **HIV-associated DLBCL**. - The primary drivers of HIV-associated DLBCL are linked to HIV-induced immunodeficiency, not specific inherited genetic predispositions for lymphoma. *Age over 55 years* - While the incidence of many cancers increases with **age**, for **HIV-associated DLBCL**, age is less prominent than the degree of **immunodeficiency** caused by HIV. - The stronger prognostic factor remains the state of the immune system, particularly a **low CD4 count**, which is often exacerbated by poor cART adherence. *Male sex* - While there are minor differences in cancer incidence between sexes, **male sex** is not a primary or significant independent risk factor for **HIV-associated DLBCL**. - The risk is predominantly driven by factors related to HIV infection itself and the resulting immune dysfunction.

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