Hemophagocytic lymphohistiocytosis (HLH) is an aggressive and life-threatening syndrome of excessive immune activation. It most frequently affects infants from birth to 18 months of age, but the disease is also observed in children and adults of all ages. This study aims to evaluate patients with HLH with the clinical features, laboratory data, treatment modalities, and the prognostic significance of these factors on survival of patients after eight weeks of different therapies used. Thirty-six patients who were hospitalised in Basrah Children Teaching Specialty Hospital were evaluated for suspected HLH from January 2015 until October 2021. Retrospective analysis using descriptive statistics was done, applying demographic, clinical, and different laboratory indices as well as bone marrow analysis in an attempt to identify possible risk factors that might be related to prognosis and survival of patients. Of the total patients , 66.7% were males and 33.3% were females. The most common age group was infants less than 12 months old (47%), with a lesser percentage for other age groups. All patients had fever (100%), 94.4% of them had pallor, and hepatosplenomegaly was found in 77.8%. Furthermore, anaemia was detected in 94% of the cases, while neutropenia was in 80% of them and thrombocytopenia in more than 85% of the total cases. All patients present with elevated ferritin (100%) and an elevated triglyceride level (94.4%). Moreover, high bilirubin in more than 60% of patients with elevated liver enzymes in more than 50% of patients, low albumin less than 2.5 gm/dL in 61% of the cases, and LDH elevated in almost all of them (100%). Hemophagocytosis was found in 97.2% of the bone marrow, and coagulopathy with significant lengthening of the PT and PTT was found in 38.9% and 41.7%, respectively. It was discovered that age less than 12 months was associated with early death and poor outcome, as well as jaundice, decreased urine output, and generalised body oedema. SGOT, SGPT levels greater than 200 U/L, albumin levels less than 2.5 m/d, prolonged PT, and PTT all had a negative impact on survival, with patients with risk prognostic parameters having a higher mortality rate. The study concludes that HLH has a high mortality if undiagnosed early. Therefore, early identification of clinical symptoms and signs with adequate laboratory analysis and early initiation of therapy according to well-known therapies might improve the survival among affected patients.

Index Terms : HLH, Basrah, Iraq, clinical feature, prognosis, outcome