Comparison of klotho, a marker of chronic inflammation, with other biomarkers of inflammation in individuals living with human immunodeficiency virus

Objective: HIV/AIDS patients have a chronic viral infection with an HIV-specific course and some pathological processes caused by it. A chronic inflammatory environment develops with viral reservoirs, latency, and dysbiosis. This environment causes immune activation, immune dysregulation and immune aging, along with continuous cytokine release. All these immunological events affect many systemic pathways and form the basis of AIDS and non-AIDS comorbidities. Klotho protein is known as an anti-aging protein and is a cofactor in Fibroblast growth factor 23 (FGF23) signalling mechanism. Many studies in recent years have shown that it is involved in the inflammatory process of many aging-related diseases, including atherosclerosis, vascular calcification, diabetes, and chronic kidney disease (CKD). The aim of this study was to investigate whether Klotho protein is affected by the chronic inflammatory process in HIV/AIDS patients. Materials and Methods: The study included 84 HIV-infected patients followed under the outpatient clinic conditions by Çukurova University Faculty of Medicine, Department of Infectious Diseases and Clinical Microbiology, and 100 HIV-negative individuals as a control group. Demographic data, chronic diseases and body mass indexes of the patients and controls who met the study criteria were recorded. In addition, CD4+ and CD8+ T lymphocyte counts, CD4/CD8 ratios and HIV RNA levels of HIV-infected patients were recorded and neutrophil/lymphocyte ratios and platelet/lymphocyte ratios were calculated. Serum Klotho, IFABP and hs-CRP levels were studied by taking serum samples from both groups. IBM SPSS Statistics Version 20.0 package program was used for statistical analysis of the data. Statistical significance level was taken as 0.05 in all tests. Results: The mean age of all individuals participating in the study was calculated as 41.11±11.74(18-73), and 147 (79.9%) of these individuals were male and 37 (20.1%) were female. The patient and control groups were similar in terms of age and gender. While serum Klotho levels were statistically significantly lower in the patient group (p<0.001), serum IFABP levels were significantly higher in the patient group (p<0.001). There was no significant difference between the two groups for serum hs-CRP level (p=0.843). A significant inverse correlation was found between serum Klotho levels and IFABP levels (r==-0.468, p<0.001). In addition, there was a significant negative correlation between Klotho level and CD8+ T lymphocyte count at the time of diagnosis (r=-0,241, p=0,037) and a significant positive correlation with CD4/CD8 ratio (r=0,230, p=0,047). In the HIV positive patient group, a positive correlation was found between platelet/lymphocyte ratio calculated with current laboratory values and serum Klotho level (r=0.355, p=0.001). Conclusion: In our study, it was shown that serum Klotho levels were affected in individuals living with HIV. The inverse correlation between IFABP and Klotho serum levels and the correlation with CD8+ T lymphocyte count and CD4/CD8 ratio at the time of diagnosis strengthened the conclusion that Klotho protein may play a role in chronic inflammation, immunactivation and immunoregulation in HIV. The use of Klotho protein as a new biomarker in individuals living with HIV is thought to be useful in the field of screening, treatment and preventive health services. Key words: HIV/AIDS, klotho, IFABP, hs-CRP, inflammation