High Seropositivity for Helminths in Immunosuppressed Patients with Peripheral Eosinophilia

Eosinophilia is a hallmark of many helminthic infections. However, the underlying parasitic etiology often goes undetected-especially in immunosuppressed patients. We aimed to evaluate the helminthic seropositivity in immunosuppressed patients with peripheral eosinophilia at a tertiary care hospital in north India.

In this retrospective observational cross-sectional study, a total of 115 immunosuppressed patients with eosinophilia were subjected to serological testing for six common helminths, i.e., IgG antibodies against Strongyloides stercoralis, Toxocara canis, Trichinella spiralis, Echinococcus granulosus, and Taenia solium by ELISA; IgG4 antibodies against Wuchereria bancrofti by ELISA; and W. bancrofti antigen by immunochromatographic assay. Absolute eosinophil counts (AEC) and clinical-demographic data were analyzed using non-parametric tests and Spearman correlation statistics.

Overall, 34 patients (29.6%) were positive for at least one parasitic serology, with S. stercoralis being the most common (18.3%), followed by T. canis (11.3%), T. spiralis (6.1%), W. bancrofti (5.2%), E. granulosus (5.2%), and T. solium (1.7%). Multiple seropositivities were detected in 14 (12.2%) patients. Seropositive patients had significantly higher median AEC than seronegatives (3021 vs. 1495 cells/µL, Wilcoxon p = 0.008). A statistically significant correlation was found between AEC and number of positive serologies per patient (Spearman's ρ = 0.269, p = 0.003). A graded relationship between increasing seropositivity and severity of AEC was noted (Cochran-Armitage trend p = 0.006).

Nearly 30% of immunosuppressed patients with peripheral eosinophilia had serological evidence of helminthic infections. Helminth serology panel testing for persistent or unexplained eosinophilia along with clinical evaluation may facilitate early diagnosis and management in immunocompromised hosts.