**Question:** Which of the following is not seen in HIV patient with CD count less than 100 per micro litre, who has non-productive cough?

**Core Concept:** HIV (Human Immunodeficiency Virus) infection primarily affects the immune system, leading to a decrease in CD4+ T cells count. A CD4+ T cell count less than 100 per micro litre indicates a severe depletion of these cells. Non-productive cough is a symptom that can be associated with HIV infection.

**Why the Correct Answer is Right:** The correct answer is **D** - "HIV-related interstitial pneumonia" because it is a condition specific to HIV infection, which is not listed among the options provided.

In HIV patients with low CD4+ T cell count (less than 100 per micro litre), opportunistic infections become more common. Among these, Pneumocystis jirovecii pneumonia (PCP) is a well-known complication, which is usually seen in patients with CD4+ T cell count less than 200 cells/uL. However, it is not a condition exclusive to patients with low CD4+T cell count less than 100 per micro litre.

**Why Each Wrong Option is Incorrect:**

A. "Pneumonia due to Pneumocystis jirovecii": Although Pneumocystis jirovecii pneumonia (PCP) is a common complication in HIV patients, it is seen in patients with a lower CD4+ T cell count, typically less than 200 cells/uL.

B. "Pneumonia due to Mycobacterium tuberculosis": While tuberculosis is a common infection in HIV-positive patients, the correct condition is pneumocystis pneumonia (PCP), which is specific to HIV and requires a CD4+ T cell count less than 200 cells/uL, not less than 100 cells/uL.

C. "Cough due to bronchial asthma": Bronchial asthma is a respiratory condition unrelated to HIV infection and its immune system compromise. The correct answer should be a condition associated with HIV and low CD4+ T cell count, not asthma.

D. "HIV-related interstitial pneumonia": This is not a specific condition related to a CD4+ T cell count of less than 100 cells/uL. HIV-related interstitial pneumonia is typically seen at a lower CD4+ T cell count, typically less than 200 cells/uL.

**Clinical Pearl:**

In HIV-positive patients with a CD4+ T cell count less than 100 cells/uL, the most likely cause of the non-productive cough is HIV-related interstitial pneumonia. This condition occurs due to the weakened immune system, leading to an increased susceptibility to opportunistic infections. The correct answer should be a condition related to low CD4+ T cell count (less than 200 cells/uL) rather than a specific count of 100 cells/uL. Interstitial pneumonia is a respiratory condition that develops due to the weakened immune system in HIV infection, leading to