INI-CET 2010 — Pathology
1 Previous Year Questions with Answers & Explanations
Fetomaternal transfusion of fetal RBCs in mother can be detected by: UPSC 08; TN 08; AIIMS 10
INI-CET 2010 - Pathology INI-CET Practice Questions and MCQs
Question 1: Fetomaternal transfusion of fetal RBCs in mother can be detected by: UPSC 08; TN 08; AIIMS 10
- A. Electrophoresis
- B. Indirect Coomb's test
- C. Direct Coomb's test
- D. Betke-Kleihauer test (Correct Answer)
Explanation: ***Betke-Kleihauer test*** - The **Kleihauer-Betke test** (or acid elution test) detects fetal hemoglobin (HbF) in maternal blood. Fetal red blood cells, which contain HbF, are more resistant to acid elution and retain their hemoglobin, appearing stained, while adult red blood cells containing HbA lose their hemoglobin and appear as 'ghost' cells. - This visual differentiation allows for the quantification of **fetomaternal hemorrhage**, which is crucial for determining the appropriate dose of anti-D immunoglobulin in Rh-negative mothers [1]. - This is the **gold standard test** for detecting and quantifying fetomaternal transfusion. *Electrophoresis* - **Hemoglobin electrophoresis** is used to identify and quantify different types of hemoglobin (e.g., HbA, HbS, HbC, HbF) in a blood sample. While it can detect HbF, it is not the primary or most practical method for routinely quantifying the small percentage of fetal cells in maternal circulation in the context of fetomaternal hemorrhage. - It is typically used for diagnosing **hemoglobinopathies** and thalassemias, not for accurately determining the extent of fetomaternal transfusion. *Indirect Coombs test* - The **Indirect Coombs Test** (ICT) detects *antibodies circulating in the serum* that are capable of binding to red blood cells [1]. It is commonly used for **antibody screening** in prenatal care and for cross-matching blood transfusions. - While it can screen for maternal antibodies against fetal red blood cell antigens, it does not directly quantify the volume of fetal blood that has entered the maternal circulation. *Direct Coombs test* - The **Direct Coombs Test** (DCT) detects antibodies *attached directly to the surface of red blood cells*, typically indicating autoimmune hemolytic anemia or a hemolytic transfusion reaction. - It is used to detect antibodies on the infant's red blood cells in cases of **hemolytic disease of the newborn**, but not to quantify fetal cells in the mother's circulation. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 469-470.