Acquired alpha 1-antitrypsin deficiency in tropical pulmonary eosinophilia.

Background & objectives: Observation of an increased frequency of an intermediate deficiency of serum alpha1-antitrypsin (α1-AT) in patients with Tropical Pulmonary Eosinophilia (TPE) was earlier reported. Though the possibility of existence of an acquired deficiency was suggested, without phenotyping a hereditary α1-AT deficiency in TPE could not totally be ruled out. In this study, we have done Pi (Protease inhibitor) phenotyping to investigate the possibility of association of any heterozygous (or homozygous) α1-AT deficiency in patients with TPE. Methods: Serum a1antitrypsin (α1-AT) was measured in 103 patients (Group A) with TPE, 99 patients with pulmonary eosinophilia who had associated intestinal worm infestation (Group B) and 43 healthy volunteers who served as controls. In 19 α1-AT deficient patients (9 of Group A and 10 of Group B), α1-AT level was measured before and after treatment. In 58 patients with TPE and in 5 controls, phenotyping was done. Results: Fifteen patients of Group A and 16 from Group B showed intermediate α1-AT deficiency (150 mg % or less. None of the control subjects had α1-AT deficiency (<200 mg%). After treatment with DEC and/or deworming, in 19 patients there was a significant (P < 0.001) rise in α1-AT levels. Results of phenotyping showed that all had M1 or M2 allele and none had S or Z variant (either homozygous or heterozygous) thus ruling out any underlying genetic cause for the observed α1-AT deficiency. Interpretation & conclusions: The observed α1-AT deficiency may be due to the chronic inflammation in TPE and associated oxidative stress. However, in such α1-AT deficient patients with TPE and those with worm infested pulmonary eosinophilia, faecal α1-AT concentration and faecal α1-AT clearance should be routinely estimated to rule out the possibility of any intestinal protein loss.

Serum neopterin levels in HIV infected patients with & without tuberculosis.

BACKGROUND & OBJECTIVE: Three categories of prognostic markers are best documented as having significance in relation to prognosis of HIV infection. These include HIV viral load, CD4 T-cell levels and plasma levels of soluble markers of immune activation. The plasma activation markers, like neopterin, tumor necrosis factor alpha (TNF-alpha), interleukins etc., are products of cytokine activity and represent immunologic changes throughout the body. There is not much information available on serum neopterin estimation in patients infected with both HIV and tuberculosis (TB), though neopterin levels are known to be elevated in pulmonary TB patients. In this study we attempted to correlate neopterin levels with the presence of tuberculosis in HIV infected and uninfected individuals and studied the changes after antituberculosis treatment. METHODS: Serum neopterin concentrations were measured by high performance liquid chromatography (HPLC) in 25 HIV-seropositive (HIV-TB) and 10-seronegative (TB) patients with tuberculosis before, during and at the end of antituberculosis therapy (ATT). S-neo was also measured in 10 HIV-seropositive asymptomatic individuals and 10 healthy controls. The results were correlated with clinical, bacteriological and immunological status. RESULTS: All TB patients regardless of HIV status had elevated s-neo concentrations at diagnosis, which declined gradually during treatment. Patients with HIV/TB with CD4 counts < 200/mm(3) had the highest levels at baseline with a steep fall during treatment. The median level at the end of treatment was significantly higher in HIV/TB than in TB patients, despite clinical improvement and bacteriological clearance of Mycobacterium tuberculosis. HIV infected asymptomatic individuals had neopterin levels that were higher than healthy controls but lower than HIV-TB patients. INTERPRETATION & CONCLUSION: Serum neopterin levels are elevated in HIV-positive patients, with the highest levels in those with tuberculosis and CD4 counts < 200/mm(3). Though the levels decrease with anti tuberculosis therapy, persistently elevated levels indicate progressive HIV disease and a poor prognosis.

Bioavailability of rifampicin following concomitant administration of ethambutol or isoniazid or pyrazinamide or a combination of the three drugs.

BACKGROUND & OBJECTIVES: Poor bioavailability of rifampicin (R) in combination with other anti-tuberculosis drugs such as isoniazid (H), pyrazinamide (Z), and ethambutol (E) is a subject of much concern for the last few decades. This could be due to an interaction between R and other drugs. An investigation was therefore undertaken to examine the bioavailability of R in the presence of H, Z and E or a combination of the three drugs. METHODS: The study included eight healthy volunteers, each being investigated on four occasions at weekly intervals once with R alone and with three of the four combinations on the three remaining occasions. A partially balanced incomplete block design was employed and the allocation of R or the drug combinations was random. Plasma concentrations of R at intervals up to 12 h were determined by microbiological assay using Staphylococcus aureus as the test organism. The proportion (%) dose of R as R plus desacetyl R (DR) in urine excreted over the periods 0-8 and 8-12 h was also determined. Bioavailability was expressed as an index (BI) of area under time concentration curve (AUC) calculated from the plasma concentrations or proportion of dose of R excreted as R plus DR in urine with the combinations to that with R alone. RESULTS: The bioavailability indices based on AUC were 0.96 with RE, 0.76 with RH, 1.08 with RZ and 0.65 with REHZ. The indices based on urine estimations (0-8 h) were similar, the values being 0.94, 0.84, 0.94 and 0.75, respectively. A second investigation revealed that the decrease of bioavailability of R with H was not due to the excipients present in H tablets. INTERPRETATION & CONCLUSION: Isoniazid alone or in combination with E and Z reduces the bioavailability of R. Urinary excretion data offer a simple and non invasive method for the assessment of bioavailability of R.