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Question #46537
The Question
A patient suspected of recent HIV exposure tests negative on a standard antibody-detecting ELISA, yet a simultaneous RT-PCR test reveals a high viral titer in the blood. Which of the following immunological mechanisms best explains the physiological basis of this 'window period'?
Options
- A.
HIV primarily infects B-lymphocytes, directly inhibiting their differentiation into plasma cells and halting early antibody production.
- B.
The delayed response or initial depletion of CD4+ T-helper cells impairs the cytokine signals required for B-lymphocyte activation and subsequent antibody production.
- C.
The viral reverse transcriptase enzyme actively degrades the host's circulating immunoglobulins, keeping the titer below the ELISA detection threshold.
- D.
Macrophages act as an HIV factory, sequestering all viral antigens intracellularly and completely preventing their exposure to the humoral immune system.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
ELISA|HIV|CD4 Cells|Active vs Passive Immunity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that 'ELISA is the diagnostic test for AIDS' without connecting it to the underlying immunology.
The trap tests the functional dependency of B-cells on CD4+ T-helper cells (Humoral Immunity bridge).
Failing to recognize that an antibody-detecting ELISA requires an intact T-helper response leads to confusion about why a highly infectious patient might test negative.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | ELISA Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |