Decreased Prevalence of Lymphatic Filariasis among Diabetic Subjects Associated with a Diminished Pro-Inflammatory Cytokine Response (CURES 83)

Abstract

Epidemiological studies have shown an inverse correlation between the incidence of lymphatic filariasis (LF) and the incidence of allergies and autoimmunity. However, the interrelationship between LF and type-2 diabetes is not known and hence, a cross sectional study to assess the baseline prevalence and the correlates of sero-positivity of LF among diabetic subjects was carried out (n = 1416) as part of the CURES study. There was a significant decrease in the prevalence of LF among diabetic subjects (both newly diagnosed [5.7%] and those under treatment [4.3%]) compared to pre-diabetic subjects [9.1%] (p = 0.0095) and non-diabetic subjects [10.4%] (p = 0.0463). A significant decrease in filarial antigen load (p = 0.04) was also seen among diabetic subjects. Serum cytokine levels of the pro-inflammatory cytokines—IL-6 and GM-CSF—were significantly lower in diabetic subjects who were LF positive, compared to those who were LF negative. There were, however, no significant differences in the levels of anti-inflammatory cytokines—IL-10, IL-13 and TGF-β—between the two groups. Although a direct causal link has yet to be shown, there appears to be a striking inverse relationship between the prevalence of LF and diabetes, which is reflected by a diminished pro-inflammatory cytokine response in Asian Indians with diabetes and concomitant LF.

Effect of Filarial Infection on Serum Inflammatory and Atherogenic Biomarkers in Coronary Artery Disease (CURES-121)

“…Previously, we have shown reduced prevalence of LF among T2DM subjects and have also provided evidence for the possible involvement of filarial-mediated immune modulation in possibly conferring protection against T2DM (extended hygiene hypothesis). 9 Recently, our findings were confirmed in a murine model of high-fat diet-induced insulin resistance, infected with the intestinal helminth, Nippostrongylus brasiliensis.…”

“…To quantify the filarial antigen levels and prevalence, sera were analyzed using the W. bancrofti Og4C3 antigen capture enzyme-linked immunosorbent assay (ELISA) (Tropbio, James Cook University, Townsville, Queensland, Australia) according to the manufacturer's instructions. 8,9 A cut-off value of 128 antigen units was considered positive for LF.…”

Decreased Prevalence of Lymphatic Filariasis Among Subjects with Type-1 Diabetes

“…We have recently shown reduced prevalence of LF among persons with T2DM and have also provided evidence for the possible involvement of filarialmediated immune modulation in conferring protection against T2DM. 19 Reduced prevalence of LF was associated with reduced levels of filaria-specific IgG4 among persons with T1DM. Because B .…”

“…17,18 We previously showed reduced prevalence of lymphatic filariasis (LF) among persons with type-2 diabetic (T2DM). 19 In the present study, we examined the prevalence of LF among persons with T1DM.…”

Filarial Abundant Larval Transcript Protein ALT-2: An Immunomodulatory Therapeutic Agent for Type 1 Diabetes

“…Quite strikingly this transcript gets abundantly expressed and secreted almost like 'magic bullets' at this stage of the parasite development; presumably, part of natural defense mechanism to curb the upheaval of host's inflammatory response and to survive and safeguard the patency of the infection [25]. As already mentioned, the available evidence suggests on the development of some natural protection from type 1 diabetes among infected populace in a filarial endemic area [26] which might be part of this immune evasion mechanism by the parasite.…”