Effect of Age and Sex On Immunological Activation In Relation To Infection With Echinococcus granulosus

Abstract

Background: Human cystic echinococcosis (CE) was caused by the larval stage of Echinococcus granulosus (E. granulosus) and characterized by its chronicity. It had been believed that chronicity of CE might be favored by a skewing of the host’s immune response to a Th2 response which was affected by age and sex.Aim of study: to assess some cytokines (IL-2, IL-6, IL-12 and TNF- α) in relation to age and sex as a part of host-parasite relationship.Materials and Methods: A total of 50 patients suffering from CE and 38 apparently healthy control that consulted Bagdad Teaching Hospital/Medical City from February to July, 2005 were enrolled in this study. Ultrasonography was done to all patients and control while Computed Tomography was done to confirm the Ultrasonography diagnosis. Blood sera were stored in (-20C˚) to be used for evaluation of the serum cytokines level of IL-2, TNF- α, IL-6 and IL-12 by enzyme immunoassay (ELISA). Results: This study showed that in male patients with CE more than 60 years, the IL-2 , TNF- α ,IL-6 and IL-12 were (1348 ±97.33 ; 11.51±1.10; 29996 ±385.10 and 27.91±3.8) in comparison to (1804 ±111.49; 5.46±0.84; 20987 ±223.54 and 42.6 ±3.56) in patients aged (40-60) and (1820 ±103.50; 4.89±1.03; 21228 ± 209.71 and 40.04 ±4.47) in patients aged < 40 years with statistical significance ( P value < 0.05). The IL-2, TNF- α and IL-6 were significantly changed (2425 ± 104.52 ; 14.2± 2.85; 19973 ± 266.75 ) in menopausal patient group in comparison to childbearing age (2103 ± 354.19; 10.3±1.20; 23412 ±539.4) while they were insignificantly changed (2425 ± 104.52; 14.2± 2.85; 19973 ± 266.75)( P value >0.05) in menopausal female patients in comparison to aged matched male patients(2211 ±132.7; 9.92±1.32; 21039 ± 315.29) and significantly changed in childbearing female patients (2103 ± 354.19; 10.3±1.20; 23412 ±539.4) in comparison to aged matched male patients (1832± 355.6; 7.9±1.06; 20873 ± 638.21) respectively (P value < 0.05). Conclusions: young and middle age groups male patients with CE had a more predominant protective Th1 immune response than elderly male patients while the female menopausal women had a more protective Th1 immune response than childbearing women. Female in the childbearing age had a more protective Th1 immune response against CE in comparison to aged matched male group while there was insignificant immune response in menopausal women in relation to aged matched male group. Predominant Th2 immune response in elderly male and childbearing female might favor more parasite growth . Higher estrogen level might augment more growth of CE , and it is advisable to decrease the frequency of pregnancy rate unless surgical treatment of CE performed. Hormonal replacement therapy containing estrogen in menopause should be given with caution for patients with CE as the may favor more parasite growth. .