Publication

Abstract : Background and aim: Secondary Hematophagocytosis Lymphohystiocytosis(HLH) is a life-threatening haematological complication seen in severe Dengue fever. As per HLH-2004 protocol, HLH can be diagnosed if 5 out of 8 clinical/laboratory criteria are fulfilled. Patients with severe Dengue are generally unfit for bone marrow test. Soluble IL-2R(sIL-2R) level is another criterion which can help diagnose HLH if available. Here, we demonstrate the utility of sIL-2Rtest in establishing a definite diagnosis of HLH in patients with severe Dengue. Method: We retrospectively analyzed data ofsIL-2R levels sent for children with severe Dengueand suspected HLH. sIL-2R testing was done by solid phase sandwich ELISA using Diaclone Human CD25/IL-2R ELISA kit. The normal range was determined at 1555-10,800pg/ml in serum sample. In our study, levels ≥10,800pg/ml were considered elevated. Results: A total 20 children (age2-15years, male-13 &female-7) diagnosed with severe Dengue and suspected HLH whose sIL-2R levels were sent were included in this study. Number of patients fulfilling individual HLH-2004 criteria are shown in Table 1.If we exclude sIL-2R level as a diagnostic criterion then only 10% of the cohort could be diagnosed with HLH. Inclusion of sIL-2R as a diagnostic criterion helped confirm the diagnosis of HLH in another 60% patients. In the remaining 30%, HLH was ruled out. All patients diagnosed with HLH were treated with dexamethasone and one also received intravenous immunoglobulin. Those diagnosed as HLH had a prolonged intensive care unit stay with mechanical ventilation requirement in 71%, high frequency oxygen in 71% and inotrope support in 29%. Mortality amongst those with HLH was 35%. Conclusion:sIL-2R is a handy tool which can help fulfil 5/8 criteria to diagnose HLH in severe dengue obviating need for bone marrow examination in these critically ill patients. Early diagnosis of HLH can be life-saving in severe dengue.