Lymphatic filariasis: possible pathophysiological nexus with oxidative stress

Wuchereria bancrofti-mediated lymphatic filariasis is widely prevalent. Diversity in immune response presumably may lead to myriad clinical presentations, such as overt chronic filariasis, occult filariasis with atypical systemic manifestation and asymptomatic microfilariae carrier state. Anticipated oxidative stress during inflammatory response to infective conditions might complicate the immune response and thus might alter the disease outcome. The present study was carried out to assess the status of oxidative stress in different clinical presentations of bancroftian filariasis. Twenty-five microfilariae carriers and 30 cases each of chronic filariasis and occult filariasis were compared to 30 endemic normal individuals. Serum malondialdehyde level and superoxide dismutase enzyme activity were measured by spectrophotometric methods and levels of filarial antigen were measured by ELISA. In the filarial cases, the levels of these parameters were assayed again after treatment with diethylcarbamazine citrate (DEC). Results showed significant (P < 0.05) association of oxidative stress with chronic and occult filariasis but not with microfilarial. carriers. DEC therapy in both clinical cases and carriers resulted in a significant reduction of oxidative stress associated with decreased antigen level (P<0.01). These findings suggest the possible involvement of oxidative stress in filarial disease pathology. (C) 2005 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.