COMPARATIVE HISTOPATHOLOGICAL STUDY OF PULMONARY TUBERCULOSIS IN HUMAN IMMUNODEFICIENCY VIRUS-INFECTED AND NONINFECTED PATIENTS

Setting: Clinical features of human immunodeficiency virus (HIV)-assoc iated tuberculosis depend upon the patients' residual immunity, An imm une-dependent presentation has also been described at the histopatholo gical level in many extra-pulmonary sites, but no descriptions have so far been made on the histopathology of HIV-associated pulmonary tuber culosis. Objective: To compare the histopathological features of pulmo nary tuberculosis in HIV-infected subjects and seronegative patients. Design: We carried out a retrospective comparative study on 16 HIV-inf ected subjects and 16 seronegative patients with culture-proven pulmon ary tuberculosis who underwent transbronchial biopsy, We evaluated the bacillary burden and the parenchymal inflammatory reaction by means o f a four-graded scoring system giving an approximate quantitative meas ure of the two parameters. Results: HIV-associated pulmonary tuberculo sis was found to differ significantly from disease forms seen in seron egative patients, with a significant tendency to develop highly bacill ary and poorly reactive histopathological pictures along with the down grading evolution of immune function. Conclusion: Pathologic features of pulmonary tuberculosis in HIV-infected subjects differ from those e ncountered in seronegative patients depending upon the individual immu nity of the former, HIV-associated progressive depletion of CD4+ lymph ocytes leads to substantial changes in pulmonary reactivity to Mycobac terium tuberculosis; multibacillary pictures in a background of loose inflammatory reactions are quite common findings at the extreme phase of HIV-related immune deterioration.