Strongyloides stercoralis infection in patients with systemic lupus erythematosus: diagnosis and prevention of severe strongyloidiasis.

Aim: Strongyloides stercoralis infection is usually chronic and asymptomatic and may persist undiagnosed for decades. However, in immunocompromised individuals, the infection can cause hyperinfection and dissemination. Therefore, early diagnosis is essential to prevent severe forms of strongyloidiasis. The aims of this study were: (i) to evaluate the frequency of S. stercoralis infection in patients with systemic lupus erythematous (SLE) and (ii) to estimate specific immunoglobulins G (IgG) and E (IgE) production using an enzyme-linked immunosorbent assay (ELISA) method.

Methods: Seventy-five SLE patients treated with prophylactic anthelmintic therapy were evaluated using the spontaneous sedimentation (SS), Baermann-Moraes (BM) and agar plate culture (APC) methods. Serum anti-S. stercoralis IgG and IgE antibodies were measured by ELISA.

Results: Using parasitological methods, the frequency of intestinal parasites was 10.7%, whereas the frequency of S. stercoralis infection was 1.3%. The sensitivity of the ELISA to detect anti-S. stercoralis IgG and IgE was 80% and 76.9%, respectively. Both assays presented the same specificity of 96.7%. The frequency of anti-S. stercoralis IgG and IgE was 16% and 28%, respectively. Six patients were positive for both antibodies.

Conclusions: Diagnostic approaches using high-sensitivity parasitological methods and the detection of specific antibodies are essential for the diagnosis of strongyloidiasis in immunocompromised patients. Early detection of infection can alter the course of the disease via appropriate treatment, preventing the occurrence of severe strongyloidiasis.