INTERLEUKIN-6 – A DIFFERENTIAL MARKER OF BACTERIAL PNEUMONIA AND NEWLY DIAGNOSED PULMONARY TUBERCULOSIS IN HIV-POSITIVE PATIENTS

Abstract

SUMMARY. The goal is to investigate the level of IL-6 in HIV-infected patients with bacterial and tuberculosis lung lesions, and to evaluate the possibilities of its use as a differential marker for early diagnosis of these infections.

Materials and methods. Using a retrospective method (case-control), a study of patients with HIV infection with bacterial and tuberculous lung lesions was conducted. The object of the study was the content of IL-6 in the serum of patients with HIV infection with lung pathology. The subject of the study was the clinical course of pulmonary pathology in HIV infection and HIV/TB co-infection. Diagnosed pulmonary tuberculosis in HIV-positive patients. To study the quantitative parameter of IL-6 in the process of work, reagents from JSC “Vector-Best” were used. The determination of the indicator was carried out using the immunoenzymatic method.

The content of IL-6 in the test serum was determined in pg/ml. The statistical analysis of the obtained data was carried out by the methods of variation and correlation statistics with the use of software. The average value of the series (M), the error of the average arithmetic value (m), and the mean square deviation (σ) were calculated. Significant differences between mean values (p) were calculated using Student’s test (t). Also, Pearson’s χ2 test of agreement was used to assess differences between groups. The correlation coefficient (r) was used to determine the relationships between the studied indicators. Statistical processing of data was performed using a PC with a package of application programs “Microsoft Excel 2007” (Microsoft Corporation) and an additional set of statistical analysis programs (Statistica v 6.0 “StatSoft”).

Results and Discussion. During the examination of patients of both groups for the content of IL-6 in blood serum in the group of patients with HIV infection with bacterial pneumonia, the values ranged from 2.3 to 10.46 pg/ml and on average were (5.77±0.32) pg/ml, while in the group of patients with HIV/TB co-infection (VDTB) the values were significantly higher and ranged from 21.33 to 79.23 pg/ml and averaged (47.94±2.95) pg/ml. Data on the content of IL-6 in the blood serum of patients with HIV infection with bacterial pneumonia and patients with HIV/TB co-infection indicate that the level of IL-6 was significantly increased in patients of both groups (p₁<0.001), but significantly higher in the category of patients with HIV/TB co-infection.

The Pearson analysis of this indicator made it possible to establish that in patients with pneumonia, the IL-6 content in the blood serum, which was equal to or less than 10.03 pg/ml, occurred more often than in patients with tuberculosis (χ²=65.5; p<0.001).

Conclusion. The conducted study revealed an increased level of IL-6 in groups of patients with HIV infection with bacterial and tuberculosis (VDTB) lung damage. According to the correlative analysis, it was determined that with HIV/TB co-infection, the level of this indicator was significantly higher than in the group of HIV-infected patients with bacterial pneumonia. This process is due to the peculiarities of the pathophysiological mechanism of inflammation, and will allow to differentiate the investigated nosologies in the category of patients with HIV infection with pulmonary pathology.