Preliminary evaluation of a Mycobacterium tuberculosis lipooligosaccharide (LOS) antigen in the serological diagnosis of tuberculosis in HIV seropositive and seronegative patients.

OBJECTIVE: To assess the value of detection of specific IgG or IgM antibodies against three polar glycolipids of Mycobacterium tuberculosis in HIV seropositive and seronegative patients with documented active tuberculosis. DESIGN: Using an ELISA test, concentrations of IgM and IgG antibodies against phenolic glycolipid Tb1 (PGL Tb1), 2.3 diacyl trehalose (DAT) and polar lipooligosaccharide (LOS) were measured in the serum of 36 patients with active tuberculosis: 16 tuberculosis patients were coinfected with HIV (TB HIV+), and 20 were HIV seronegative (TB HIV-). 104 control sera were tested: they were collected from 50 healthy blood donors and from 54 asymptomatic HIV seropositive patients. Specificity, sensitivity and predictive positive and negative values were calculated. RESULTS: For the LOS antigen tested, sensitivity, specificity and predictive positive value of specific IgG antibodies were 75%, 95% and 84% respectively among the 36 tuberculosis patients. No significant results were obtained either with the IgM against the LOS antigen or with IgG against the DAT and PGL Tb1 antigens. Significant sensitivity and positive predictive values were demonstrated only with the ELISA test measuring specific IgG against the LOS antigen. The sensitivity was greater in the TB HIV+ subgroup (94%) as compared with the TB HIV- (60%) subgroup. These results were not related to different potential factors such as the site of disease (pulmonary or extrapulmonary) or by the acid-fast bacteria load as detected by the smear microscopic (Ziehl-Neelsen) examination. CONCLUSIONS: The results suggest that of the 3 antigens tested, only the LOS antigen is a potential marker for detecting the development of tuberculosis in HIV patients.

[Frequency of bronchopulmonary isolation of Aspergillus species in patients infected with human immunodeficiency virus: pathogenic role?]. / Fréquence de l'isolement broncho-pulmonaire d'Aspergillus species chez des patients infectés par le virus de l'immunodéficience humaine: rôle pathogène?

Prevalence of aspergillosis in patients infected with the human immunodeficiency virus (HIV) is unknown. Mycologic findings in bronchopulmonary specimens from 614 HIV-positive patients sent to a parasitology laboratory between June 1, 1989 and May 31, 1991 were analyzed retrospectively; medical records of Aspergillus sp--positive patients were studied to evaluate the potential pathogenic role of this organism. Prevalence of Aspergillus sp. was 2.7% in bronchoalveolar lavage (BAL) specimens, (21/757), 15.1% in sputum specimens (3/53), 12.6% in bronchial aspirates (11/87), 7% in protected brush specimens (2/28), and 16.6% in lung biopsy specimens (4/24). A total of 20 patients (rate = 3.14%) had lung specimens positive for Aspergillus sp. (A. fumigatus 95% and A. niger 5%). Among them, 66% had a single positive specimen (14.3% with a positive smear) and 33% had several positive specimens (mean 4.9 +/- 3.3). Four patients (20%) with a more than 20-month history of AIDS and less than 36 CD4+ cells per microliter had documented pulmonary aspergillosis; three of these patients also had a current or past history of pulmonary mycobacterial infection. Rate of recovery of Aspergillus sp. in LAB specimens was low. The other specimens were harvested because of clinically suggestive manifestations. However, in 20% of patients with positive specimens. A. fumigatus was the cause of patent infection; these patients had severe AIDS-related immunodeficiency.