CHANGES IN SERUM NEOPTERIN AND SERUM BETA(2)-MICROGLOBULIN IN SUBJECTS WITH LUNG INFECTIONS

Our aim was to investigate whether serum neopterin and beta2-microglob ulin have any value in the distinction between Pneumocystis carinii pn eumonia (PCP) and pneumonia due to extracellular bacteria. Also, to st udy whether neopterin and beta2-microglobulin would correlate with the clinical course of lung infections in human immunodeficiency virus (H IV)-positive and HIV-negative patients. Thirty HIV-positive subjects w ith PCP, 9 HIV-positive patients with bacterial pneumonia, and 16 HIV- negative patients with bacterial pneumonia were investigated. Thirty e ight asymptomatic HIV-positive subjects and 48 healthy blood donors we re used as controls. The HIV-positive patients with PCP and the HIV-po sitive subjects with bacterial pneumonia had significantly and similar ly elevated levels of neopterin and beta2-microglobulin in the acute s tage. In the weeks before the acute stage of PCP, neopterin and beta2- microglobulin had been increasing. After start of treatment, serum neo pterin declined significantly, whilst serum beta2-microglobulin remain ed elevated. The HIV-negative patients with bacterial pneumonia had si gnificantly increased serum concentrations of both markers in the acut e stage, and had decreasing serum concentrations in the weeks after tr eatment. We conclude that neither neopterin nor beta2-microglobulin se em to be of value in distinction between PCP and bacterial pneumonia i n HIV-positive subjects. In the HIV-positive patients, neopterin may c orrelate partly with the clinical activity of PCP, whilst serum beta2- microglobulin may remain elevated after PCP, despite treatment and rec overy. The elevated level may, in part, be due to repeated infections and progression to acquired immune deficiency syndrome (AIDS). In the HIV-negative patients with pneumonia both parameters seem to correlate with disease activity and recovery.