Anti - HDV and anti - HEV antibodies were identified active and as previous infections that can be used to study the HEV and HDV epidemiology. Previous HDV and HEV studies have reported the presence of HEV and HDV infections in different regions of the Iran (
13,
22); however, there is not enough information regarding HIV co - infection in the Iran. In another study, HIV infected patients has also been reported a low anti - HDV prevalence in the Iran, however, the number of patients is increasing (
21).
The finding of the present study showed that ALT mean levels among group II and group III patients were higher than that among group I patients. The progression in the liver cirrhosis and damages was caused by increasing ALT levels (
23,
24). HEV and HDV infections cause increased ALT levels, thus, developing liver cirrhosis. Moreover, results were reported that active HDV and HEV infections were an increased risk of liver cirrhosis compared to chronic HDV and HEV infections. In addition, raised anti- and proinflammatory cytokine levels during acute HEV infection correlated with ALT levels (
25). Therefore, ALT released from the damaged liver cells causes development of liver tissue destruction. In addition, in the present study, ALT mean levels in HIV, HCV, and HEV co - infection patients was higher due to HCV increased distraction of tissue of the liver; however, this difference was not significant.
HIV viral load and HEV/HDV antibodies presence among patients were in a direct relationship that was similar with previous studies (
26). In addition, HIV load level in group II patients was higher than group I patients. In addition, among HCV, HIV, and HEV co - infected patients, HIV viral load significantly increased. In order to support the former result, most patients from group II and III were included in untreated HIV infected patients. Although all of the patients were HIV infected, however HEV and HDV infections were reported more among active HIV infected patients with higher ALT levels. However, in another study there was no difference in anti - HEV seroprevalence between patients with HIV infection and control subjects (
27). Analysis of CD4 count showed that the majority of II and III group patients had CD4 < 250. Mentioned outcomes that indicated immune system suppression by HIV infection was caused to increase the risk of HEV and HDV infections as well as liver cirrhosis that was against some previous studies (
28). Among group II patients, the rate of anti - HEV IgG was higher than HIV, HCV, and HEV co - infection patients. The presence of HCV cause changes in the host immune system and reduce humoral immunity, therefore, co - infection of these patients with HCV probably cause a reduced immune system against the HEV infection.
This discrepancy was attributed to the regional differences in HEV prevalence in different countries: owing to endemic characteristics and high-accelerated HEV prevalence in the developing countries (
29), liver cirrhosis had a high progression rating. Transmission route of HEV is oral fecal (
30) and difference with transmission of HCV and HBV as well as being unknown of rate of HEV infection in population of developing countries have caused increasing of prevalence of HEV. HIV co - infected patients with HDV were shown higher liver cirrhosis (
31). It was related to the presence of the HBV as a crucial factor in this co - infection. In this study, group II patients were compared with group III. The majority of parameter had no significant difference, however, only the ALT of group III patients was significantly higher than group II patients. Due to this, HDV infected patients had multiple co - infections of HIV and HCV, which caused increase of destroying the liver tissue (
9,
32). However, the rate of prevalence of HEV was significantly higher than HDV infection, probably one of the reasons being endemic of HEV in Iran.
This investigation was indicated the most infected patients belonged to low levels of literacy section and urban residents, which some previous studies approved (
33). Thus, the absence of enough information about endemic HEV, the low level of public awareness about disease and its transmission like HEV transmission through the fecal - oral, don’t have enough information about co - infection HDV and HBV, and does not check HDV in HBV infected patients were the main reasons for high prevalence among the population. Generally, the study indicated prevalence of HIV co - infection with HDV or HEV was considerable.
The higher liver damage was reported among group III patients or group II patients compared to group I patients, it was attributed to weak immune system and high ALT levels among patients. Many studies have suggested that acute HEV was considered a subclinical and self - limiting disease (
34); however, co - infection of HEV with HIV cause chronicity of HEV infection and the period of time in which fibrosis progression occurred was alarmingly short. Thus, in co - infection HEV with HIV, progression to cirrhosis may be even faster than descried in HBV or HCV/HIV co - infection (
35). Early diagnosis of HIV and HEV co - infection and starting antiviral therapy can lead to reduce clinical complications and hazardous consequences for the patient and clear HEV. Due to interfering between HDV with replication of HBV (
36), HDV infected patients were shown as a failure to identify HBV individuals. Medical teams can take appropriate treatment and diagnosis for HEV and HDV infections by having enough information about disease prevalence and characteristics. Moreover, the medical team should investigate not only HCV and HBV but also HEV and HDV.