Haemophagocytic Lymphohistiocytosis: New Insights into Diagnosis

Introduction: Haemophagocytic lymphohistiocytosis (HLH) or haemophagocytic syndrome is a very fatal and an underdiagnosed disease which involves a pathway of hypercytokinemia, that results in Multiorgan Dysfunction Syndrome (MODS) and poor survival. Although an early diagnosis is important to decrease mortality, the definitive diagnosis is an enigma due to the absence of confirmatory gold standard tests. Since the range of laboratory assays involved in the diagnosis of HLH is wide, practicing pathologists should be familiar with the disease so, that they can appropriately flag results and convey them to the clinicians. Aim: To diagnose Haemophagocytic lymphohistiocytosis and find its advantage over the criteria used in 2004. Materials and Methods: The cross-sectional study was accomplished in the Pathology Department of Sriram Chandra Bhanja Medical College and Hospital Cuttack, Odisha, India over a period of 5 years and 4 months in which 26 cases were evaluated. A complete clinical history, haematological, biochemical work-up and H-scoring by Fardet L et al., in 2014 was done to dwell into the depths of aetiology of HLH. Univariate statistical analysis was done to understand the basic statistics of the data in term of frequency and percentage. Results: Total of 26 patients were diagnosed and the age ranges from 47 days to 65 years; two were infants. The average age of the patients was 28 years. The H-score was more accurate than the previous (2004) criteria to diagnose HLH. The diagnostic sensitivity improved by 7.7% by using H-score. The underlying aetiology was found to be infective, autoimmune and malignancies in our cases. Conclusion: H-score, a new scoring system proposed helps to diagnose HLH in a robust and efficient way for early diagnosis and treatment.