HBV and HCV Seroprevalence in Hospital Admissions for Thalassemia Major in Bengbu, China

In this cross-sectional study, the study population included all patients with thalassemia major referred to Bengbu Hospital in China during the years 2018 to 2019. The study sample consisted of 630 patients with thalassemia major eligible for the present study who were selected by census sampling.

Inclusion criteria for the study were all patients with thalassemia major referred to Bengbu Hospital in China from 2018 to 2019, whose case information was complete and they did not have hepatitis B before the blood transfusion. Also, people who had hepatitis B before the start of the blood transfusion and patients who died during the study were excluded from the study. Vaccination response rate based on antibody titer (HBs-Ab) is defined in two ways: titer greater than 10 IU / ml as a complete response and titer less than 10 IU / ml as an incomplete response to the vaccine. In this study, SPSS-22 software, t-test and Chi-square tests, descriptive statistics, central indices and dispersion were used for analysis. Patient information was recorded completely confidential and all information of the patient was confidential and was not made available to any natural or legal entity. The conditions of the study were described to the subjects and their consent was obtained and no additional costs were imposed on the patients.

Out of 630 patients, 319 (50.6%) were female and 311 (49.4%) were male. The age range was 6-67 and the mean age was 31.05 ±7.61. Also, most of the people were in the age group of 26-35. The average number of visits for blood transfusion in the whole sample is 10.88± 5.8. The results of Table I show that 529 patients (84%) had Rh positive blood type and 101 patients (16%) had Rh negative blood type. In ABO blood group, the highest prevalence belongs to group O (35.7%).

HBs-Ab titer was divided into two groups, including greater than 10 (IU / ml) as adequate response and less than or equal to 10 (IU / ml) as non-vaccine response and requiring reminder dose. Of the 630 thalassemia major patients who required frequent blood transfusions, 566 (89.8%) had adequate response and only 64 (10.2%) individuals had antibody levels less than 10 (IU / ml). three (0.9%) women aged 26 to 35 years were HBs-Ag positive and 45 patients (7.1%) including 19 men (6.1%) and 26 women (8.1%) were HCV-Ab positive as well.

Table II shows a comparison of HBV antibody responses by mean age, mean number of blood transfusions per year, gender, and HBs-Ag status. Examining this table, we find that out of 566 patients (89.8%) with antibody titers greater than 10 (IU / ml), 281 (90.3%) were male and 285 (89.3%) were female. On the other hand, in the group of patients with a titer less than or equal to 10 (IU / ml), 30 (9.6%) were male and 34 (10.6%) were female. The results of mean age in the two groups with t-test showed that individuals with antibody titers greater than 10 are significantly younger than the other group (p = 0.03). The mean age of individuals with a titer greater than or less than 10 (IU / ml) was 31.11 ± 7.12 and 42.12 ± 9.21, respectively. Also, one patient (0.2%) had HBs-Ag positive with HBs-Ab titer greater than 10 (IU / ml) and 2 patients (3.1%) had HBs-Ag positive with HBs-Ab titer less than 10 (IU / ml). The mean number of blood transfusions in two groups of patients with antibody levels less than and more than 10 (IU / ml) in the table above shows that these two values were not significantly different between the two groups and this difference was not statistically significant (p = 0.09).

Table III shows the comparison of the frequency and percentage of HBs-Ab and HCV-Ab titers by age groups of patients in this study. In the table above, antibody titers against hepatitis B virus surface antigen and also HCV infection status were compared in different age groups.

Examining this table, we find that in older age groups, the percentage of people who had an antibody titer greater than 10 (IU / ml) decreases. Similarly, with increasing of age the percentage of HCV infection in these patients increases that these results were statistically significant.

Table IV shows a comparison of HCV-Ab status by number of injections, gender, and mean age. Examining this table, we find that 45 patients including 19 (6.1%) males and 26 (8.1%) females were HCV-Ab positive, no difference concerning gender (p> 0.05) was observed. The mean age was 42.2 ± 5.12 in infected individuals and 31.4 ± 4.66 years in healthy ones. Mean age in HCV-Ab positive individuals was significantly higher than healthy individuals (P <0.05). The mean of referrals for blood transfusion in HCV-Ab positive and negative patients was 14.25 ± 4.7 and 5.34 ± 10.13, respectively. Although HCV patients had more transfusions, this relationship was not significant (P = 0.6).

Despite the use and development of accurate HBV screening methods using modern equipment and the implementation of these methods by blood transfusion centers in various countries, including China, cases of hepatitis B after blood transfusion are still reported. In the present study, out of 630 patients with thalassemia major, three were HBs-Ag positive and 45 were HCV-Ab positive, with a prevalence of 0.5% and 7.1%, respectively. There wasn’t any significant relationship between the number of injections and HBs-Ab and HCV-Ab positivity. Also, 89.8% of subjects had antibody titers above 10 IU / ml, which is consistent with previous studies (Sharifi et al., 2010; Rehman et al., 2012; Azarkeivan et al., 2009).

In the present study, frequency of people with HCV were higher in older age groups. The mean age of these patients was higher than the other group, which has been confirmed in previous studies (Covas et al., 1993). For example, a study in the United States in 2004 showed that the prevalence of HCV positive was significantly correlated with the age of patients. This may be because these patients have received blood or blood products for a longer period of time and were more likely to be exposed to the contamination of unscreened blood.

The results of this study showed that 35 patients (36.4%) were HBV-DNA positive while only one of these patients was HBs-Ag positive. In frequency of latent HBV infection in the two groups of complete and incomplete response to the vaccine was not any differece, which is in line with previous studies (Sabat et al., 2015).

Sabat et al. (2015) conducted a study on 174 patients in 2015 to investigate latent HBV infection in patients with transfusion-dependent thalassemia. The results of their study showed that one patient (0.5%) was HBs-Ag positive, 38 patients (21.8%) were HBc-Ab positive, 53 patients (30.4%) were HBs-Ab positive and 6 patients were (3.4%)

Table II. Comparison of HBV antibody titer response (IU/ml) by mean age, mean number of blood transfusions per year, sex and status of HBs-Ag.

HCV-Ab positive. Also in their results, HBV-DNA was positive in 9 patients (15%), and 50% of people who were only HBc-Ab positive were HBV-DNA positive as well.

One of the limitations of this study is that it is a retrospective study and its working method is file reading, which causes the exclusion of some samples due to information deficiencies. Another limitation of the present study is that the information available in patients’ records is qualitative as well as the lack of information about HBc-Ab, because in recent studies much attention has been paid to the latent HBV infection (OBI). Present study suggests that further studies be performed by performing HBV-DNA and HBc-Ab tests, as well as estimating the prevalence of HBV in other patients requiring frequent blood transfusions, such as those with hemophilia or thalassemia cycle.

Transfusion-transmitted infections are one of the most important problems in patients with thalassemia major. Estimating the prevalence of these infections, especially HBV, we can be aware of the results of disease prevention strategies, look for causes of them and think of new solutions to solve this problem. In the present study, the prevalence of HBs-Ag positive in thalassemia patients admitted to Bengbu Hospital in China was 0.2% and 89.8% of patients had a HBs-Ab titer of more than 10, indicating that the majority of participants had good vaccination coverage.

The research is supported by key project of Anhui Provincial Department of Education, Establishment and clinical application of a new confirmatory test method for hepatitis C virus infection (No. KJ2018A1024).

The authors have declared no conflict of interest.