Biomarkers. Cytokines, Leptospira.
Purpose: Leptospirosis is a
tropical zoonotic illness, in which the role of immune response in the pathogenesis
is proven but poorly understood. Response of cytokines is said to play a key role
in disease progression and pathogenesis. There are proven studies on
pro-inflammatory cytokines like TNFα, IL-6 and anti-inflammatory like IL-10 in human
leptospirosis however, the role of IL-2, IL-4, IL-15, GCSF and MCP-2 needs more
comprehensive studies. Present study was conducted to evaluate the role of IL-2,
IL-4, IL-15, GCSF and MCP-2 in human leptospirosis as prognostic indicator.
Methods: Blood samples from
patients meeting the inclusion criteria for leptospirosis were included in the
study. PCR and IgM ELISA were carried out for diagnosis. Serum cytokine levels
in Leptospira positive patients and in controls were estimated by ELISA. Statistical
analysis was done using IBM SPSS Statistics 20 and Med Calc 16.1. software.
Results: Out of 270, 45(16.7%) patients
were confirmed as cases of leptospirosis. The mean level of the cytokines
(IL-15, MCP-2, G-CSF) differed significantly between the patients and the
control group (p < 0.001). GCSF, MCP-2, IL-15 and IL-4 were elevated in most
cases. IL-2 level was depressed in 34 out of 45 cases. The AUCs for IL-2,
IL-15, MCP-2 and GCSF were 0.906 (95% CI 0.341 to 0.665), 0.929 (95% CI 0.837
to 0.978), 0.909 (95% CI 0.812-0.966) and 0.881 (95% CI 0.777 to 0.948)
respectively. On spearman rank correlation, GCSF level showed correlation with
MCP-2 (rho = 0.415, p < 0.01).
Conclusions: The study provided an understanding of cytokine patterns in
leptospirosis, and concluded that IL-15, MCP-2 and GCSF can be used as an
effective biomarker for leptospirosis and indicators of disease progressions.