Subtopic: Fundamentals of Cell structure and signaling
Question Statement:
Match hypersensitivity types in Group I with their corresponding condition
in Group I.
Group I
Group II
P. Type I
1. Erythroblastosis fetalis
Q. Type II
2. Host reaction to bee venom
R. Type III
3. Systemic lupus erythematosus
S. Type IV
4. Tuberculin reaction
Options:
(A) P-2, Q-3, R-1, S-4
(B) P-3, Q-1, R-4, S-2
(C) | P-2, Q-3, R-4, S-1
(D) | P-2, Q-1, R-3, S-4
Official Answer Key:
D
Step-by-Step Solution & Explanation
### **Official Solution & Concept Analysis (GATE BT 2021 Q.40)**
**1. Governing Concept**:
- **Topic**: Immunology & Gell and Coombs Hypersensitivity Classifications
- Matching hypersensitivity categories with clinical manifestations:
- **P. Type I (Immediate / IgE-mediated)** $\rightarrow$ IgE cross-linking on mast cells triggering degranulation during **host reaction to bee venom** (anaphylaxis) $\rightarrow$ **2**
- **Q. Type II (Cytotoxic / IgG/IgM-mediated)** $\rightarrow$ Maternal anti-Rh antibodies destroying fetal RBCs in **Erythroblastosis fetalis** $\rightarrow$ **1**
- **R. Type III (Immune complex-mediated)** $\rightarrow$ Deposition of circulating antigen-antibody complexes in tissues in **Systemic Lupus Erythematosus (SLE)** $\rightarrow$ **3**
- **S. Type IV (Delayed-type cell-mediated)** $\rightarrow$ CD4+ Th1 / macrophage-mediated delayed induration in the **Tuberculin skin reaction** (Mantoux test) $\rightarrow$ **4**
**2. Option Analysis**:
- **Option (A) is INCORRECT**: Misassigns Type II to SLE.
- **Option (B) is INCORRECT**: Inverts Type I and Type II.
- **Option (C) is INCORRECT**: Swaps Type II and Type IV.
- **Option (D) [P-2, Q-1, R-3, S-4] is CORRECT**: Perfectly aligned with Coombs-Gell hypersensitivity taxonomy.
**3. Final Answer**:
- **Correct Choice**: **D**
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