Screening Clinical, Laboratory and Host Markers for Diagnosis of Disease Severity in Plasmodium vivax Clinical Samples

Malaria is one of the most infectious disease that affects lives of million people throughout the world. Recently, there are several reports which indicate Plasmodium vivax (P. vivax) causing severe disease in infected patients from different parts of the world. For P. vivax disease severity, the data related to immunological and inflammatory status in human host is very limited. In the present study clinical parameters, cytokine profile and integrin gene were analyzed in P. vivax clinical patients. A total of 169 P. vivax samples were collected and categorized into severe vivax malaria (SVM; n = 106) and non-severe vivax malaria (NSVM; n = 63) according to WHO severity criteria. We measured host biomarker levels of interferon (IFN-γ), superoxide dismutase (SOD-1), interleukins viz. (IL-6, IL-10), and tumor necrosis factor (TNF-α) in patient plasma samples by ELISA for pro- and anti-inflammatory cytokines in severe malaria. Host integrin gene was genotyped using PCR assay. In our study, thrombocytopenia and anemia were major symptoms in severe P. vivax patients. In analyzed SVM and NSVM groups a significant increase in cytokine levels (IL-10, IL-6, and TNF-α) and anti-oxidant enzyme SOD-1 was found. Our study results also showed a higher pro-inflammatory (TNF-α, IL-6 and IFN-γ) to anti-inflammatory (IL-10) cytokine ratio in severe vivax patients. Integrin gene showed no mutation with respect to thrombocytopenic patients among clinically defined groups. It was observed that severe vivax cases had increased cytokine levels irrespective of age and sex of the patients along with thrombocytopenia and other clinical manifestations. The results of current findings could serve as baseline data for evaluating severe malaria parameters during P. vivax infections and will help in developing an effective biomarker for diagnosis.

Graphical Abstract