Role of soluble interleukin-2 receptor (sIL-2R) as a predictor for severe dengue infection

Annually, around half a million people with severe dengue require hospitalization, all over the globe, with around 12,500 (2.5%) succumbing to the illness. In this prospective observational study, we recruited 74 patients with dengue infection, 28 had severe dengue and 46 had dengue with warning signs. sIL-2R levels were significantly raised in the severe dengue group, compared to the warning signs group. Using an ROC curve (receive operator characteristic), at a cutoff of 5.379 ng/ml, it predicted the severe dengue classification with a p-value of < 0.001. As a marker for predicting hemophagocytic lymphohistiocytosis (HLH), the ROC curve revealed a cutoff of ≥ 5.379 ng/ml for sIL-2R levels with the AUROC being 0.83, suggesting a strong diagnostic performance(p-value < 0.001). sIL-2R levels can be used for predicting severe dengue classification with moderate sensitivity and specificity. Secondary HLH is an under-reported entity in dengue infection and early surveillance with the help of sIL-2R may be helpful in-patient care management.