RESUMO
AIM: This study aimed at investigating the presence of intestinal parasitic infections in inflammatory respiratory diseases patients during the disease attack, and measuring the acidic mammalian chitinase (AMCase) gene expression in blood before and after infection eradication. METHODOLOGY: This case-control study included 123 inflammatory respiratory diseases patients and 120 apparently healthy individuals. Repeated stool examination was done, while total and specific IgE were measured. AMCase gene expression was analysed by real time-polymerase chain reaction (RT-PCR). RESULTS: Infection was detected in 32.5% of the diseased and 23.25% of the healthy individuals. Higher rate of the helminthic infection was detected (23.57) in comparison to the protozoal (12.19%) in the patients. A significantly higher rate of infection with the chitin-rich helminths "Enterobius vermicularis & Hymenolepis nana" and level of anti-Dermatophagoide-IgE were reported in the patients (14.63%, 6.5% and 23.57%, respectively). AMCase expression was significantly higher in helminths-infected patients than the noninfected, or protozoa infected. After infection eradication, AMCase expression significantly declined in the previously helminth-infected patients (mean ± SD = 13.9 ± 3.918 before and 4.515 ± 1.93 after), but insignificantly affected in the protozoa infected (mean ± SD = 2.095 ± .285 before and 2.675 ± 1.181 after). CONCLUSION: Chitin-rich intestinal helminths are suspected to precipitate Th2-immune response in remote tissues by enhancing systemic AMCase expression through intestinal mucosa and macrophages irritation.