T4 lymphopenia in patients with active pulmonary tuberculosis

Area of Science:

• Immunology
• Infectious Diseases
• Hematology

Background:

• Pulmonary tuberculosis (TB) is a significant global health issue.
• Immune cell dysregulation is often observed in infectious diseases.
• Understanding T cell subset changes in TB is crucial for disease management.

Purpose of the Study:

• To investigate T cell (T3, T4, T8) and B cell counts in newly diagnosed pulmonary TB patients.
• To compare these counts with healthy controls from East Java.
• To explore the relationship between T4 lymphopenia and disease severity or immune markers.

Main Methods:

• Venous blood samples were collected from 26 pulmonary TB patients and 29 healthy controls.
• Flow cytometry was used to count cells expressing T3, T4, T8, and B cell markers.
• Radiological extent of lesions and PPD skin test reactions were assessed.
• Interferon-alpha levels were measured in patient and control sera.

Main Results:

• Absolute T cell counts were lower in TB patients.
• T4 (helper/inducer) cell counts were significantly reduced in patients (mean 748/mm3) compared to controls (mean 1,043/mm3).
• No significant differences were found in T8 (suppressor/cytotoxic) cell or B cell counts. The T4:T8 ratio was decreased in some patients.

Conclusions:

• The observed T4 lymphopenia in pulmonary TB patients is likely a direct immune response to Mycobacterium tuberculosis infection.
• This finding suggests it is not indicative of underlying secondary (acquired) immune deficiency.
• Further research into the immunopathogenesis of TB is warranted.