Neurocysticercosis: the effectiveness of the cysticidal treatment could be influenced by the host immunity

Neurocysticercosis, a clinically and radiologically pleomorphic parasitic disease, is still endemic to most non-developed countries of Latin America, Africa, and Asia. Anti-helminthic drugs (AHD) are generally effective and rapidly destroy parenchymal cysticerci. In contrast, several cycles of AHD are frequently necessary to damage extraparenchymally located parasites. The present study was designed to evaluate whether differences in the immunological profile of the patients is involved in the diversity of the response to AHD. To this end, a global gene expression microarray and a cytokine analysis were made. Responder patients were those showing a radiological reduction greater than 50 % in the parasite burden following AHD treatment. Microarray pre- and post-treatment comparisons showed that a total of eighteen immune-related genes were up-regulated in the five responder patients with respect the expression profile seen in the four non-responder subjects. The function of up-regulated genes exerted pro-inflammatory (ROR gamma C, Sema4A, SLAMF3, SLAMF6), anti-inflammatory (TGF beta, TNFRSF25, TNFRS18, SLAMF1, ILF2), or immunomodulatory effects (CXCL2, RUNX3, SLAMF9, TGFBR3). To further explore the causes of the heterogeneity in the response to treatment, a wide ELISA cytokine analysis was performed in serum, PBMC supernatants, and CSF samples from 39 responder and 26 non-responder patients. Responder patients showed higher CSF IL-17A levels (P = 0.04) and higher supernatant IL-6 levels (P = 0.03) 60 days after treatment. These results suggest a possible influence of pro-inflammatory cytokines on the response to AHD as observed by radiological methods, and thus the possible participation of the host immunity in the effectiveness of AHD treatment.