Out of who tested HIV positive and were on ARV therapy from August 2014 to September 2017, in the NARI clinic. A total of 165 HIV positive individuals, on ARV therapy who visited NARI clinic from August 2014 to September 2017 were considered for the study. Out of these, 34 individuals showed hepatotoxicity and constituted the first case group of HIV positive individuals showing ARV therapy associated hepatotoxicity. The remaining 131 individuals didn’t show hepatotoxicity (by LFT) and formed the second study group of HIV positive individuals on ARV therapy without hepatotoxicity. Control population consisted of 155 healthy people. The demographic profiles of the participants are outlined in table 1. The mean age ± SD of HIV infected individuals without hepatotoxicity, with HIV hepatotoxicity and control population was 40.27 ± 2.45, 37.24 ± 3.29, , and 37.25 ± 6.30 years. Each of the study population and control group has been further characterized on the basis of the NNRTI regimen (Efavirenz or Navirapine), alcohol and tobacco usage (users or non-users) and the CD4+ status (to define the stage of HIV infection). These parameters were used to categorize the study populations and the control group and the incidence of MDR1 polymorphisms were analyzed in all the categories as shown in the tables 6-9.
3.1 MDR1 polymorphisms in the cases with hepatotoxicity versus the cases without hepatotoxicity and control population
The incidence of polymorphisms of MDR1 in the two study populations is shown in table 2. MDR1 polymorphisms were not found to be distinct between HIV infected populations with and without hepatotoxicity. Although, among the cases with hepatotoxicity, the predominance of MDR1 1236TT genotype was more as compared to the non-hepatotoxic cases (17.6% versus 12.2%, OR=1.38, 95%CI: 0.45-4.12, P=0.57). Whereas, MDR1 3435TT genotype and T allele were underrepresented in the cases with hepatotoxicity as compared to the non-hepatotoxic HIV-infected people (35.3% versus 43.5%, OR=0. 56, 95%CI: 0. 20- 1.59, P=0. 28 and 55.88% versus 62.59%, OR=0.65, P=0.13). Also, MDR1 polymorphism were not significantly different between the individuals with ARV associated hepatotoxicity and the healthy controls.
3.2 MDR1 polymorphism in the HIV-infected people without hepatotoxicity versus control population
The occurrence of polymorphisms of MDR1 (1236C/T, 3435C/T) in people with HIV infection verus the healthy population is tabulated in table 3. The healthy population followed the deviation from Hardy- Weinberg equilibrium (P=0.36, 0.13). The distribution of MDR1 polymorphism was almost alike between HIV-infected people (without hepatotoxicity) and healthy population. Although, HIV-infected people had more occurrence of MDR1 3435TT genotype than healthy people (43.5% versus 34.83%, OR=1.24, 95%CI: 0.59-2.61, P=0.57). The dispersion of other genotypes and alleles of MDR1 polymorphisms were comparable between both groups.
3.3 Haplotypes distribution
We have likewise investigated the occurrence of different MDR1 haplotypes among the two study groups and the controls, as shown in table 4. Haplotype CT (1236*C/3435*T) was considered as a reference. The incidence of TT haplotype (1236*T/3435*T) has been found to be significantly lesser among the HIV-infected individuals with hepatotoxicity than their non-hepatotoxic counterparts (0.05% versus 0.22%, OR=0.16, 95%CI: 0.04-0.059, P=0.0065), whereas the incidence of TC haplotype (1236*T/3435*C) was significantly more in individuals with hepatotoxicity than the non-hepatotoxic ones (0.30% versus 0.11%, OR=1.96, 95%CI: 0.98-3.94, P=0.06). This suggest that haplotype TC was associated with increased severity of hepatotoxicity because of synergistic effect of gene-gene interaction. The occurrence of CC (1236*C/3435*C) and TT (1236*T/3435*T) haplotypes was lesser among the people with hepatotoxicity than healthy individuals (0.14% versus 0.30%, OR=0.34, 95%CI: 0.12- 0.94, P=0.039, 0.05% versus 0.22%, OR=0.09, 95%CI: 0.02-0.44, P=0.0032). Whereas, the incidence of TC (1236*T/3435*C) haplotype was predominantly higher in patients with hepatotoxicity compared to the control population (0.30% versus 0.13%, OR=1.94, 95%CI: 0. 87-4.37, P=0.11). The incidence of MDR1 haplotypes among the HIV infected individuals without hepatotoxicity was not significantly different from the healthy population
3.4 MDR1 polymorphisms and stages of HIV-1
The incidence of MDR1 polymorphism among people in different stages of HIV infection and the healthy controls was also studied as outlined in table 5. A reduced frequency of MDR1 1236TT genotype was found among individuals intermediate stage of HIV infection than control population (24.2% versus 41.94%, OR=0.43, P=0.09). MDR1 1236TT genotype was likely to be related with the decreased risk for progression of HIV disease. The incidence of MDR1 3435CT and 3435TT genotypes did not vary among the individuals in different stages of HIV infection and healthy population.
3.5 Gene-environment interaction
The distribution of MDR1 polymorphisms among HIV infected individuals with and without hepatotoxicity and the control group was analyzed by categorizing them on the basis of tobacco and alcohol consumption and NNRTI regimen as shown in tables 6-9. The occurrence of polymorphisms of MDR1 (1236C/T and 3435C/T) was not different among the people consuming tobacco in both the study populations and the control group. MDR1 1236TT genotype was overrepresented among the tobacco consumers than the non-consumers in the hepatotoxic group (28.6% versus 14.8%) (Table-6). Also its occurrence was higher among the alcohol consumers than the non-consumers in the hepatotoxic group (28.6% versus 14.8%, OR=1.50, 95% CI: 0.13 - 17.35, P=0.88). An increased incidence of 3435CT genotype of MDR1 was observed among the alcohol consumers than the nonusers in the HIV-infected non-hepatotoxic people (50.0% versus 32.2%, OR=2.47, 95%CI: 0.79 -7.70, P=0.12) (Table-7). The occurrence of genotype 1236TT of MDR1 was greater in nevirapine taking non-hepatotoxic individuals than efavirenz users (14.1%versus 8.7%, OR=1.93, 95%CI: 0.39- 9.45, P=0.42). Also it was greater in patients on nevirapine with hepatotoxicity than efavirenz users (21.7% versus 9. 1%, OR= 2.11, 95%CI: 0. 18 - 24.66, P=0.55). This suggest that MDR11236TT genotype along with nevirapine usage was likely to be related with the increased risk for severity of hepatotoxicity because of combined effect of gene polymorphism and environment. The occurrence of MDR1 1236CT and 1236TT genotypes were also higher in the non-hepatotoxic HIV-infected people on nevirapine than efavirenz users (43.7% versus 33 .3%, OR= 1.66, 95%CI: 0. 44 - 6.24, P=0.45 and 12.6% versus 8.3%, OR=1. 96, 95%CI: 0. 22 - 17.42, P=0. 55) (Table-8). Among the HIV-infected individuals with hepatotoxicity, who were on nevirapine and consumed alcohol, the dispersion of MDR1 1236TT genotype was greater when contrasted to the alcohol nonusers on nevirapine (40.0% versus 16.67%, OR= 2.21, 95%CI: 0. 17-29.21, P=0.55). This suggest that MDR1 1236TT genotype with nevirapine and consumed alcohol was likely to be associated with increased severity of hepatotoxicity because of combined effect of gene polymorphism and environment. The incidence of 3435CT genotype of MDR1 was greater among the alcohol consumers on navirapine than alcohol non-consumers on navirapine, in the non-hepatotoxic group (44.74% versus 33.33%, OR= 2.04, 95%CI: 0. 64 - 6.53, P=0. 23) (Table 9).