Background: Hemophagocytic lymphohistiocytosis or MAS is typified by unchecked immune activation, defined by clinical and laboratory criteria with several triggers. The underlying disease is often not obvious, presenting clinically with pathological hyperinflammation and end organ damage. sIL2r/ferritin has been hypothesised to reflect relative T cell and Macrophage activation and determine driving mechanisms of MAS and identify underlying etiology.

Objectives: Our objective was to evaluate the performance of sIL2r/ ferritin ratio in prediction of underlying etiology of HLH and identify predictors of mortality and morbidity.

Methods: We conducted a cross sectional dual center study where 40 consecutive patients admitted with HLH were prospectively recruited fulfilling diagnostic criteria from May 2022 to June 2023. The etiology was broadly classified as benign disease associated HLH (BAHS) and malignancy associated HLH (MAHS). Mortality and morbidity outcomes at 6 weeks were analysed. ROC curve was used to find an ideal cut-off for sIL2r/ferritin, LDH and Platelet in predicting the etiology. Multivariate binary logistic regression analysis was done to identify the independent predictors of malignancy.

Results: 40 patients with MAS were included, with 32(80%) having underlying benign disease and 8(20%) having an underlying malignancy. Majority of the benign triggers included infections (42.5%) followed by autoimmune disease (35%). Platelets (<38500), LDH (>617) and sIL2r/ Ferritin (0.196) were three variables that showed a statistically significant difference between groups (p=0.003, 0.014, 0.004 respectively). Survival analysis showed that MAHS patients had poorer prognosis than BAHS, although not statistically significant.

Conclusion: We suggest, actively looking for a lymphoma-associated HLH when the platelet count is less than 38500, LDH is more than 617, and the sIL2r/ Ferritin ratio of <0.196. This will be critical to establish early diagnosis of lymphoma and further and make informed decisions about further diagnostic course including histopathological diagnosis in a case of benign disease associated HLH.

REFERENCES: NIL.

Table 1.

Figure 1.

Kaplan-meier survival curves between benign and malignant etiology

Figure 2.

a) AUC/ROC curves of platelets with etiology with association of cut-off of platelet (38500) with etiology. 2b ) AUC/ROC curves of LDH with etiology with association of cut-off of LDH with etiology 2c ) AUC/ROC curves of sIL2r/ferritin with etiology with association of cut-off of sIL2r/ferritin with etiology.

Acknowledgements: NIL.

Disclosure of Interests: None declared.

© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.