Author name:
خلود كريم حسن
Supervisor name:
علي حسين ادحية
Abstract:
The present study aimed to understand the correlation between serum level of nine cytokines (IL - 1?, IL - 1RA, IL - 2, IL - 4, IL - 6, IL - 10, IL - 12, IFN - ? and TNF - ?) and their genetic polymorphisms at 16 gene positions defined by sequence specific primer - polymerase chain reaction (SSP - PCR) in pulmonary tuberculosis (PTB) patients, and in addition HLA - DQB1 gene polymorphism was also defined by SSP - PCR to determine their role in susceptibility or resistance to M. tuberculosis. Finally, serum level of cortisol was also determined in the patients.Ninety four Iraqi Arabs PTB patients (70 males and 24 females) were enrolled in the study. They were referred to the Institute of Chest and Respiratory Diseases in Baghdad for diagnosis and treatment during the period May - October 2012. A control sample of 80 apparently healthy individuals was also included and matched patients for gender (60 males and 20 females) and ethnicity. The results are summarized in the following : 1. A significant increased serum level of IL - 1? (24.16 ± 8.82 vs. 3.20 ± 1.18 pg/ml), IL - 1RA (41.31 ± 6.64 vs. 16.85 ± 5.50 pg/ml), IL - 2 (17.63 ± 3.53 vs. 7.80 ± 1.10 pg/ml), IL - 4 (9.56 ± 2.60 vs. 3.81 ± 1.70 pg/ml), IL - 10 (34.49 ± 4.60 vs. 7.61 ± 1.70 pg/ml), IL - 12 (25.16 ± 5.85 vs. 7.70 ± 1.12 pg/ml) and TNF - ? (22.52 ± 4.41 vs. 4.97 ± 1.15 pg/ml) was recorded in PTB patients compared to controls. Also, Cortisol serum level was significantly increased in patients (215.47 ± 1.33 vs. 38.63 ± 1.74 ng/ml).2. Cytokine gene polymorphism analysis revealed that neither genotypes nor alleles of IL1A - 889, IL2 - 330, IL2+166, IL4 - 590, IL4 - 33, IL6+565, IL10 - 819, IL10 - 592, IL12B - 1188 and TNF - 238 genes showed a significant variation between PTB patients and controls. In contrast, the frequency of TT genotype of IL1RN gene at position mspal 11100 showed a significant (P = 0.004) increase in PTB patients compared to controls (65.9 vs. 43.7%). For IL4 - 1098, the frequency of TT genotype was also significantly (P = 0.048) increased inpatients (82.9 vs. 70.0%). At position - 174 of IL6 gene, a significant (P = 0.002) increased frequency of GG genotype was observed in patients (55.3 vs. 31.2%). For IL10 gene, only GG genotype at position IL10 - 1082 was observed with a significant (P = 0.045) increased frequency in patients (18.1 vs. 7.5%). At position - 308 of TNF gene, a significant (P = 6.9 x 10 - 5) decreased frequency of GG genotype was observed in patients (60.6 vs. 87.5%), while GA genotype was significantly (P = 1.3 x 10 - 4) increased (38.2 vs. 12.5%). Finally, the frequency of AA genotype of IFNG gene at position +874 demonstrated a significant (P = 0.006) increase in PTB patients (55.3%) compared to controls (33.7%).3. To determine the impact of cytokine genotypes on cytokines serum level, PTB patients and controls were distributed according to their serum level in the three genotypes of each cytokine. It was found that CC genotype of IL1RNmspal 11100 in patients was observed with the highest IL - 1RA level (52.16 ± 5.81 pg/ml) compared to TT (41.39 ± 3.23 pg/ml) or TC (38.10 ± 4.54 pg/ml) genotype. The TT genotype of IL2 at position - 330 also showed the highest level of IL - 2 (22.16 ± 4.31 pg/ml) compared to TG (17.59 ± 3.40 pg/ml) or GG (13.68 ± 3.53 pg/ml) genotype in patients. The IL4 - 1098 TT genotype showed the highest level of IL - 4 in patients (10.38 ± 2.21 pg/ml) compared to TG (6.09 ± 1.20 pg/ml) or GG (3.93 ± 0.80 pg/ml) genotype. For IL10 gene, the GG genotype of IL10 - 1082 recorded the highest level of IL - 10 (40.67 ± 2.96 pg/ml), which was significantly different from AA genotype (26.66 ± 5.65 pg/ml). At position - 308 of TNF gene, serum level of TNF - ? in GG genotype of patients demonstrated a significant increased mean compared to genotype GA (24.76 ± 1.30 vs. 19.15 ± 1.12 pg/ml). At position - 238, TNF GG genotype showed a significant increase level of TNF - ? (23.02 ± 2.91 pg/ml) in patients compared to AA genotype (17.18 ± 1.53 pg/ml) of patients. Finally, IFNG+874 AA genotype was observed with the highest IFN - ? level in patients (11.07 ± 1.12 pg/ml) compared to AT (7.97 ± 1.81 pg/ml)or TT (6.10 ± 2.20 pg/ml) genotype. In contrast, no such differences were observed in controls.4. Out of the five encountered HLA - DQB1 alleles, DQB1*03 showed a significant (P = 0.005) increased frequency in PTB patients compared to controls (71.3 vs. 50.0%). It was also observed that heterozygosity at such gene locus was significantly (P = 0.03) more frequent in patients than in controls (93.6 vs. 82.5%), while homozygosity was observed with a less percentage frequency in patients compared to controls (6.4 vs. 17.5%) and the difference was also significant (P = 0.03).Accordingly, it is possible to conclude that the cytokine profile was deviated in PTB patients, and such deviation was correlated with the genotypes of some cytokines, which might also together with HLA - DQB1polymorphism confer the individual an immunogenetic predisposition to develop M. tuberculosis infection.
