Enteric Fever-Associated Hemophagocytic Lymphohistiocytosis: A Systematic Review of Clinical Characteristics and Outcomes.

Enteric fever is a major contributor to rising health care costs in developing countries. Associated disease-related complications and drug resistance further compound this problem. Hemophagocytic lymphohistiocytosis (HLH) is an uncommon complication of enteric fever with high morbidity and mortality. This systematic review aimed to evaluate the clinical characteristics and treatment outcomes in enteric fever-associated HLH syndrome. We searched major electronic databases (PubMed, Google Scholar, and Scopus) to identify the cases of enteric fever associated with HLH from inception until June 2023. Prespecified data regarding clinical presentation, outcomes, and HLH therapy were collected. A total of 53 cases of enteric fever with HLH were included in the final analysis. The mean age of patients was 20 years, and the proportions of female and pediatric patients were 52.8% and 45.3%, respectively. The mean duration of illness was 10.4 days. A total of 39.6% of patients had enteric fever-associated complications; coagulopathy and encephalopathy were the most common (23.1% and 13.5%). The overall mortality rate was 9.4% in HLH. A total of 51% of patients received HLH-specific therapy (corticosteroids in 41.5% and intravenous immunoglobulin in 20.8% of patients). On multivariate analysis, high ferritin levels (≥5,000 ng/mL) were significantly associated with mortality (hazard ratio, 3.01; 95% CI = 0.62-14.12, P = 0.041). Enteric fever with secondary HLH is associated with high mortality. This review reveals the potential role of ferritin in disease prognosis. In cases with significantly elevated ferritin levels, the role of immunosuppressants or combination antibiotics should be explored.