An effective diagnostic index for lymphoma-associated hemophagocytic syndrome

Lymphoma-associated hemophagocytic syndrome (LAHS) is a highly fatal immune disorder. Poor prognosis is partly attributed to under diagnosis or delayed diagnosis.

Early identification of LAHS patients based on the laboratory findings could improve the outcomes.

Retrospective observational cross-sectional study.

From January 2011 to June 2016, 282 adult patients with hemophagocytosis in bone marrow were enrolled, and 114 hemophagocytic lymphohistiocytosis (HLH) patients with definite underlying cause were finally included for analysis. The HLH patients were further divided into LAHS (76 out of 114) and non-malignancy-associated HLH (38 out of 114) groups.

Compared to non-malignancy-associated HLH, LAHS patients had significantly elevated lactate dehydrogenase (LDH) levels, increased thickness of spleen, higher proportion of patients with lymphadenopathy and significantly decreased peripheral blood cell count. In multivariate logistic regression model analysis, thickness of spleen ≥5 cm (OR = 17.9, 95%CI 1.35-236.6; P = 0.028), IL-6 level ≥55.1 pg/ml (OR = 12.01, 95%CI 1.03-138.9; P = 0.047) and IL-10 level ≥425.9 pg/ml (OR = 51.18, 95%CI 2.53-1035.1; P = 0.010) were independent predictors of LAHS diagnosis. Based on the regression parameters, we established a diagnostic index with weighted risk scores of 1 assigned to thickness of spleen and IL-6 level respectively, and a score of 3 assigned to IL-10 level. A diagnostic index ≥ 2 points had the best AUC value (0.889) with 84.2% of sensitivity and 93.7% of specificity for predicting LAHS.

LAHS can be considered when HLH patients have a diagnostic index ≥2 points, so actively looking for evidence of lymphoma and effective chemotherapy may be necessary.