Presence of intestinal helminths decreases T helper type 1 responses in tuberculoid leprosy patients and may increase the risk for multi-bacillary leprosy.
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-gamma 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.
Diniz
L M
LM
Hospital da Santa Casa de Misericórdia, and Dermatology Department, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
Magalhães
E F L
EF
Pereira
F E L
FE
Dietze
R
R
Ribeiro-Rodrigues
R
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000276:immunology / Q000494:pharmacology; D000947:Antigens, Helminth / Q000276:immunology / Q000494:pharmacology; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D002478:Cells, Cultured / Q000187:drug effects / Q000276:immunology; D015897:Comorbidity; D018450:Disease Progression; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D007411:Intestinal Diseases, Parasitic / Q000097:blood / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D015440:Leprosy, Lepromatous / Q000097:blood / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D015441:Leprosy, Tuberculoid / Q000097:blood / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000737:chemistry; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009166:Mycobacterium leprae / Q000276:immunology; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D018417:Th1 Cells / Q000276:immunology*; D055815:Young Adult
D000942:Antigens, Bacterial; D000947:Antigens, Helminth; C508609:IL10 protein, human; C508598:IL4 protein, human; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma