Presence of intestinal helminths decreases T helper type 1 responses in tuberculoid leprosy patients and may increase the risk for multi-bacillary leprosy

• Published in: Clinical and experimental immunology Vol. 161; no. 1; pp. 142 - 150
• Main Authors: Diniz, L.M, Magalhães, E.F.L, Pereira, F.E.L, Dietze, R, Ribeiro-Rodrigues, R
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.07.2010; Blackwell Publishing Ltd; Blackwell; Oxford University Press; Blackwell Science Inc
• Subjects: Adolescent; Adult; Aged; Analytical, structural and metabolic biochemistry; Antigens, Bacterial - immunology; Antigens, Bacterial - pharmacology; Antigens, Helminth - immunology; Antigens, Helminth - pharmacology; Bacterial diseases; Biological and medical sciences; Brazil - epidemiology; Case-Control Studies; cell-mediated immunity; Cells, Cultured - drug effects; Cells, Cultured - immunology; cellular immunity; Comorbidity; cytokines; Disease Progression; Female; Fundamental and applied biological sciences. Psychology; Human bacterial diseases; Humans; Infectious diseases; Interferon-gamma - blood; Interleukin-10 - blood; Interleukin-4 - blood; Intestinal Diseases, Parasitic - blood; Intestinal Diseases, Parasitic - complications; Intestinal Diseases, Parasitic - epidemiology; Intestinal Diseases, Parasitic - immunology; intestinal helminths; Leprosy; Leprosy, Lepromatous - blood; Leprosy, Lepromatous - complications; Leprosy, Lepromatous - epidemiology; Leprosy, Lepromatous - immunology; Leprosy, Tuberculoid - blood; Leprosy, Tuberculoid - complications; Leprosy, Tuberculoid - epidemiology; Leprosy, Tuberculoid - immunology; Leukocytes, Mononuclear - chemistry; Lymphocyte Activation - drug effects; Male; Medical sciences; Middle Aged; multi-bacillary; Mycobacterium; Mycobacterium leprae; Mycobacterium leprae - immunology; Prevalence; Prospective Studies; Risk Factors; Th1 Cells - immunology; Translational Studies; Tropical bacterial diseases; Tuberculosis and atypical mycobacterial infections; Young Adult; Brazil; Skin disease; Tuberculoid leprosy; Mycobacterium leprae; intestinal helminths; Th1 lymphocyte; Risk; Biochemistry; Cellular immunity; Mycobacterial infection; Bacteria; cytokines; Human; Digestive system; Cytokine; Gut; Increase; multi-bacillary; Infection; Mycobacteriales; Risk factor; Bacteriosis; Mycobacteriaceae; Helmintha; Multibacillary leprosy; Actinomycetes; Invertebrata
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2010.04164.x

Resistance to intracellular pathogens such as Mycobacterium leprae is dependent upon an effective T helper type 1 (Th1)-type immune response. On the other hand, intestinal helminths are known to subvert the host's immune response towards to either a Th2-type immune response or a regulatory T cell up-regulation, which may affect the host's ability to mount an effective response to mycobacteria. Here, we report a significant association between intestinal helminth infections and lepromatous leprosy [odds ratio (OR), 10·88; confidence interval (CI) 95%: 4·02-29·4; P < 0·001]. We also observed that the frequency of intestinal helminths correlated strongly with the mycobacterial index (r = 0·982, P < 0·01). Corroborating with our hypothesis, intracellular levels of interferon-γ were decreased significantly in leprosy patients co-infected with intestinal helminths when compared to leprosy patients without worms. Conversely, lepromatous leprosy patients with intestinal worms produced higher levels of both interleukin (IL)-4 and IL-10. Our results suggest that a pre-existing infection by intestinal helminths may facilitate the establishment of M. leprae infection or its progression to more severe forms of leprosy.