Current status of liver diseases in Korea: Hepatitis A

The chronological changes in the seroprevalence of anti-hepatitis A virus IgG from 2005 to 2019: Experience at four centers in the capital area of South Korea

Although universal vaccination has been administered to toddlers, South Korea has had periodic nationwide outbreaks of acute hepatitis A since the late 2000s. We examined the chronological changes in the seroprevalence of anti-hepatitis A virus (HAV) immunoglobulin G (IgG) over the past 15 years (2005-2019). We retrospectively collected data from 45,632 subjects who underwent anti-HAV IgG testing without evidence of acute HAV infection at four centers in the capital area of South Korea between January 2005 and December 2019. The seroprevalence of anti-HAV IgG was analyzed according to age and compared among seven age groups and five time periods. Additionally, age-period-cohort analyses were used to identify the age, period, and cohort effects of the seroprevalence of anti-HAV IgG. The mean age of the enrolled subjects was 39.2 ± 19.2 years, and the average anti-HAV IgG positivity rate was 66.4%. During the 15 years, the seroprevalence of anti-HAV IgG in people aged 0 to 19 years significantly increased over time (P < .001). In people aged 20 to 29 years, the seroprevalence slightly decreased to that of the early 2010s (31.3% in 2005-2007 to 19.7% in 2011-2013) but rebounded to 39.5% in 2017 to 2019. In contrast, the seroprevalence of anti-HAV IgG in those aged 30 to 49 years decreased over time (P < .001). The seroprevalence of anti-HAV IgG in those aged 20 to 39 years in 2017 to 2019 was still less than 40%. In addition, the seroprevalence of anti-HAV IgG in people aged 50 to 59 years has recently decreased. Since the introduction of the universal vaccination, the seroprevalence of anti-HAV IgG in children and young adults has gradually increased. However, the seroprevalence of anti-HAV IgG in people in their 20s remains low, and the seroprevalence of anti-HAV IgG in people in their 30s and 40s is gradually decreasing. Therefore, a new strategy for HAV vaccination is needed for those in their 20s to 40s.

Seropositive rate of the anti-hepatitis A immunoglobulin G antibody in maintenance hemodialysis subjects from two hospitals in Korea

BACKGROUND/AIMS

Hepatitis A virus (HAV) is a self-limiting infectious disease, but 1% of subjects develop fulminant hepatitis. The prevalence of the anti-HAV immunoglobulin G (IgG) antibody in hemodialysis subjects in Korea remains unknown. The purpose of this study was to describe and compare the seropositive rate of anti-HAV antibody among hemodialysis subjects in two hospitals according to age group.

METHODS

A total of 170 hemodialysis subjects were evaluated for the seropositive rate of the anti-HAV IgG antibody and its titer.

RESULTS

Of the 170 maintenance hemodialysis subjects in two hospitals (Kangnam 92 vs. Chuncheon 78), 79 (46.5%) were male. The mean age was 53.2 years old, and 94.1% of the subjects were over 40 years old. The median vintage of hemodialysis was 29.0 months. Anti-HAV antibody was found in 163 subjects (95.9%), with no significant difference between the two areas (Kangnam 97.8% [n = 90] vs. Chuncheon 93.6% [n = 73]). Subjects younger than 40 years old showed a seropositive rate of 50%, while the seropositive rate increased with age for subjects aged 40 or older (p for trend < 0.001). Seropositive subjects from Kangnam showed a higher anti-HAV antibody titer than those from Chuncheon (median: Kangnam 14.2 vs. Chuncheon 11.7). Only age influenced seropositivity. The only factor that influenced the antibody level was the location of hospital (p < 0.001).

CONCLUSION

The seropositive rate of the anti-HAV antibody in hemodialysis subjects was 95%, which is similar to findings in the general population. Active immunization against hepatitis A is strongly recommended for hemodialysis subjects under 40 years of age after anti-HAV testing.

Phenotypic Characteristics of PD-1 and CTLA-4 Expression in Symptomatic Acute Hepatitis A

Background/Aims

The immunoregulatory molecules programmed death 1 (PD-1) and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) are associated with the dysfunction of antiviral effector T-cells, which leads to T-cell exhaustion and persistent viral infection in patients with chronic hepatitis C and chronic hepatitis B. Little is known about the role of PD-1 and CTLA-4 in patients with symptomatic acute hepatitis A (AHA).

Methods

Peripheral blood mononuclear cells were isolated from seven patients with AHA and from six patients with nonviral acute toxic hepatitis (ATH) during the symptomatic and convalescent phases of the respective diseases; five healthy subjects acted as controls. The expression of PD-1 and CTLA-4 on T-cells was measured by flow cytometry.

Results

PD-1 and CTLA-4 expression during the symptomatic phase was significantly higher in the T-cells of AHA patients than in those of ATH patients or healthy controls (PD-1: 18.3% vs 3.7% vs 1.6%, respectively, p<0.05; CTLA-4: 23.5% vs 6.1% vs 5.9%, respectively, p<0.05). The levels of both molecules decreased dramatically during the convalescent phase of AHA, whereas a similar pattern was not seen in ATH.

Conclusions

Our findings are consistent with a viral-protective effect of PD-1 and CTLA-4 as inhibitory molecules that suppress cytotoxic T-cells and thereby prevent the destruction of virus-infected hepatocytes in AHA.

Prognostic indicators for acute liver failure development and mortality in patients with hepatitis A: consecutive case analysis

PURPOSE

Due to the seroepidemiological shift in hepatitis A (HA), its severity, mortality, and complications have increased in recent years. Thus, the aim of this study was to identify predictive factors associated with poor prognosis among patients with HA.

MATERIALS AND METHODS

A total of 304 patients with HA admitted to our institution between July 2009 and June 2011 were enrolled consecutively. Patients with complications defined as acute liver failure (ALF) were evaluated, and mortality was defined as death or liver transplantation.

RESULTS

The mean age of patients (204 males, 100 females) was 32 years. Eighteen (5.9%) patients had progressed to ALF. Of the patients with ALF, 10 patients (3.3%) showed spontaneous survival while 8 (2.6%) died or underwent liver transplantation. Multivariate regression analysis showed that Model for End-Stage Liver Disease (MELD) and systemic inflammatory response syndrome (SIRS) scores were significant predictive factors of ALF. Based on receiver operating characteristics (ROC) analysis, a MELD≥23.5 was significantly more predictive than a SIRS score≥3 (area under the ROC: 0.940 vs. 0.742, respectively). In addition, of patients with a MELD score≥23.5, King's College Hospital criteria (KCC) and SIRS scores were predictive factors associated with death/transplantation in multivariate analysis.

CONCLUSION

MELD and SIRS scores≥23.5 and ≥3, respectively, appeared to be related to ALF development. In addition, KCC and SIRS scores≥3 were valuable in predicting mortality of patients with a MELD≥23.5.

Changes in the seroprevalence of IgG anti-hepatitis A virus between 2001 and 2013: experience at a single center in Korea

Background/Aims

The incidence of symptomatic hepatitis A reportedly increased among 20- to 40-year-old Korean during the late 2000s. Vaccination against hepatitis A was commenced in the late 1990s and was extended to children aged <10 years. In the present study we analyzed the changes in the seroprevalence of IgG anti-hepatitis A virus (HAV) over the past 13 years.

Methods

Overall, 4903 subjects who visited our hospital between January 2001 and December 2013 were studied. The seroprevalence of IgG anti-HAV was analyzed according to age and sex. In addition, the seroprevalence of IgG anti-HAV was compared among 12 age groups and among the following time periods: early 2000s (2001-2003), mid-to-late 2000s (2006-2008), and early 2010s (2011-2013). The chi-square test for trend was used for statistical analysis.

Results

The seroprevalence of IgG anti-HAV did not differ significantly between the sexes. Furthermore, compared to the seroprevalence of IgG anti-HAV in the early 2000s and mid-to-late 2000s, that in the early 2010s was markedly increased among individuals aged 1-14 years and decreased among those aged 25-44 years (P<0.01). We also found that the seroprevalence of IgG anti-HAV in individuals aged 25-44 years in the early 2010s was lower than that in the early 2000s and mid-to-late 2000s.

Conclusions

The number of symptomatic HAV infection cases in Korea is decreasing, but the seroprevalence of IgG anti-HAV is low in the active population.

Seroepidemiology of hepatitis a in South Korea: a nationwide study by the Eone Reference Laboratory

Background

We evaluated the recent prevalence of serologic markers of hepatitis A virus (HAV) in South Korea.

Methods

The study data were the results of 60 126 anti-HAV (total) tests and 30 786 anti-HAV IgM tests that were performed during April 2009 through March 2010 by the Eone Reference Laboratory at the request of 1935 institutions throughout Korea.

Results

The overall positivity rate was 51.06% on the anti-HAV (total) test and 11.20% on the anti-HAV IgM test. As compared with the other age groups the rate of anti-HAV (total) positivity was significantly lower (P < 0.001), and the rate of anti-HAV IgM positivity was significantly higher (P < 0.001), among Koreans aged 11 to 40 years. The seroprevalence of anti-HAV IgM significantly differed according to region but not by referral date.

Conclusions

This was the largest nationwide study in South Korea by 1 laboratory, and it provides useful recent baseline data on hepatitis A in Asia. The findings suggest that active immunization of younger Koreans should be made a priority.

Does chronic hepatitis B infection affect the clinical course of acute hepatitis A?

The impact of chronic hepatitis B on the clinical outcome of acute hepatitis A remains controversial. The aim of present study was to evaluate the clinical characteristics of acute hepatitis A in cases with underlying chronic hepatitis B compared to cases of acute hepatitis A alone. Data on 758 patients with acute hepatitis A admitted at two university-affiliated hospitals were reviewed. Patients were classified into three groups: group A, patients with both acute hepatitis A and underlying chronic hepatitis B (n = 27); group B, patients infected by acute hepatitis A alone whose sexes and ages were matched with patients in group A (n  = 54); and group C, patients with acute hepatitis A alone (n = 731). None of the demographic features of group A were significantly different from those of group B or C, except for the proportion of males and body weight, which differed from group C. When comparing to group B, clinical symptoms were more frequent, and higher total bilirubin and lower albumin levels were observed in group A. When comparing to group C, the albumin levels were lower in group A. There were no differences in the duration of hospital stay, occurrence of acute kidney injury, acute liver failure, prolonged cholestasis, or relapsing hepatitis. This study revealed that clinical symptoms and laboratory findings were less favorable for patients with acute hepatitis A and chronic hepatitis B compared to those with acute hepatitis A alone. However, there were no differences in fatal outcomes or serious complications.

Seroprevalence of hepatitis virus infection in men who have sex with men aged 18-40 years in Taiwan

BACKGROUND/PURPOSE

Men who have sex with men (MSM) are at increased risk for hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infections than the general population. Comparisons of the seroprevalence rates of these hepatitis viruses between HIV-positive and HIV-negative MSM are rarely performed in Taiwan.

METHODS

Between January 2009 and June 2010, data on the serologies for HAV, HBV, and HCV were collected from two groups of patients: HIV-negative MSM, aged 18-40 years, who sought voluntary counseling and testing (VCT) for HIV infection, and HIV-positive MSM of the same age group who sought HIV care at the National Taiwan University Hospital. Both groups of patients were also tested for syphilis.

RESULTS

During the 18-month study period, 690 HIV-negative MSM and 438 HIV-positive MSM were enrolled and tested for anti-HAV antibody, HBV surface antigen (HBsAg), hepatitis B core antibody (anti-HBc antibody), and anti-HCV antibody. HIV-positive MSM were older than HIV-negative MSM (30.5 ± 5.4 vs. 25.8 ± 4.7 years, p < 0.01). For HIV-positive MSM, the mean CD4 lymphocyte count was 477.6 ± 230.0 cells/μL and 46% of them had undetectable plasma HIV RNA load (< 40 copies/mL by reverse transcription-polymerase chain reaction assay). The overall seroprevalence rates of HAV, HBsAg, and HCV in HIV-positive MSM were 15.1%, 16.4%, and 5.5%, respectively, while in HIV-negative MSM, they were 7.4%, 6.2%, and 0.4%, respectively. In the multivariate analysis, age was significantly associated with seropositivity for HAV (OR [per one age group increase]: 1.96; 95% CI: 1.6-2.5), HBsAg (OR: 2.02; 95% CI: 1.6-2.6), anti-HBc (OR: 2.68; 95% CI: 2.3-3.2), anti-HCV (OR: 1.67; 95% CI: 1.0-2.7), and anti-HBs (OR: 1.25; 95% CI: 1.0-1.5). HIV infection was associated with seropositivity for HBsAg (OR: 1.73; 95% CI: 1.1-2.7), anti-HBc (OR: 2.44; 95% CI: 1.8-3.3), HCV (OR: 8.91; 95% CI: 2.5-31.4), and syphilis (OR: 11.21; 95% CI: 6.7-18.9).

CONCLUSION

HIV-positive MSM have a higher seroprevalence rate of HBV and HCV infection than HIV-negative MSM in Taiwan. Vaccination and safe-sex counseling should be provided to prevent the transmission of hepatitis viruses among MSM who may be engaged in high-risk behaviors.

Epidemiological changes in hepatitis A in Korea: increasing age and its effect on clinical outcomes

Korea has recently experienced an increasing number of acute hepatitis A cases. We investigated the dynamics of hepatitis A and changes in the mean age of patients in a hospital in Seoul, Korea. Mean age increased consistently from 19 years in 1996 to 30 years in 2009 (P < 0·0001). Between two acute hepatitis A outbreaks in 1998–1999 and in 2008–2009, mean age increased from 23 to 30 years (P < 0·001). However, the hepatitis A clinical outcomes were similar between the outbreaks. Duration of hospital stay, creatinine level and prothrombin time did not differ. Throughout the study period, individuals born in the 1970s and 1980s comprised the largest proportion (84%) of patients. As this susceptible generation ages, the mean age of hepatitis A patients in Korea will increase consistently. However, at present, the impact of increasing age on clinical outcomes is not apparent.

Comparison of the Clinical Features of Hepatitis A between HBsAg-Positive and HBsAg-Negative Patients

BACKGROUND/AIMS

The notion that acute hepatitis A superimposed on chronic hepatitis B infection leads to a worse outcome than acute hepatitis A alone remains controversial. The aim of this study was to determine the influence of the presence of hepatitis B surface antigen (HBsAg) on the severity of acute hepatitis A.

METHODS

We retrospectively analyzed 449 patients hospitalized for acute hepatitis A from January 2000 to February 2010 and compared clinical outcomes based on the presence of HBsAg.

RESULTS

Of the 449 patients, 30 patients were in the HBsAg-positive group and 419 in the HBsAg-negative group. The HBsAg-positive group was older than the HBsAg-negative group (36.1±8.3 vs 31.8±8.5 years, p=0.004); however, other baseline characteristics were similar between the 2 groups. Mean peak values of prothrombin time, serum total bilirubin, and serum creatinine at admission were significantly higher in the HBsAg-positive group. When comparing clinical outcomes between the 2 groups, gastrointestinal bleeding, acute renal failure, and acute liver failure were more frequently observed in the HBsAg-positive group. In particular, the incidence of acute liver failure was approximately 9-fold higher in the HBsAg-positive group than in the HBsAg-negative group (23.3% vs 3.3%; odds ratio [OR], 8.80; p<0.001). Multivariate analysis showed that HBsAg (OR, 7.43; 95% confidence interval [CI], 2.56 to 21.57) and age (OR, 1.07; 95% CI, 1.02 to 1.13) were independent risk factors for the occurrence of acute liver failure.

CONCLUSIONS

In patients with chronic hepatitis B infection, acute hepatitis A is associated with more severe clinical outcomes, including acute liver failure, compared with patients with acute hepatitis A alone.

Prevalence of IgG anti-HAV in patients with chronic hepatitis B and in the general healthy population in Korea

Background/Aims

Few studies have investigated hepatitis A virus (HAV) seroepidemiology in Koreans with chronic liver disease (CLD). This study compared the prevalence of IgG anti-HAV between the general healthy population and patients with hepatitis B virus-related CLD (HBV-CLD), with the aim of identifying predictors of HAV prior exposure.

Methods

In total, 1,319 patients were recruited between June 2008 and April 2010. All patients were tested for IgG anti-HAV, hepatitis B surface antigen (HBsAg), and antibodies to hepatitis C virus. The patients were divided into the general healthy population group and the HBV-CLD group based on the presence of HBsAg. The seroprevalence of IgG anti-HAV was compared between these two groups.

Results

The age-standardized seroprevalence rates of IgG anti-HAV in the general healthy population and patients with HBV-CLD were 52.5% and 49.1%, respectively. The age-stratified IgG anti-HAV seroprevalence rates for ages ≤19, 20-29, 30-39, 40-49, 50-59, and ≥60 years were 14.3%, 11.2%, 45.5%, 90.5%, 97.6% and 98.3%, respectively, in the general healthy population, and 0%, 9.8%, 46.3%, 91.1%, 97.7%, and 100% in the HBV-CLD group. In multivariate analysis, age (<30 vs. 30-59 years: OR=19.339, 95% CI=12.504-29.911, P<0.001; <30 vs. ≥60 years: OR=1060.5, 95% CI=142.233-7907.964, P<0.001) and advanced status of HBV-CLD (OR=19.180, 95% CI=4.550-80.856, P<0.001) were independent predictors of HAV prior exposure.

Conclusions

The seroprevalence of IgG anti-HAV did not differ significantly between the general-healthy-population and HBV-CLD groups. An HAV vaccination strategy might be warranted in people younger than 35 years, especially in patients with HBV-CLD.

Seroprevalence of hepatitis a and associated socioeconomic factors in young healthy korean adults

BACKGROUND/AIMS

An epidemiologic shift of hepatitis A virus (HAV) seroprevalence is expected due to an improvement in socioeconomic status in young adults in Korea. We investigated the age-specific seroprevalence and socioeconomic factors associated with HAV seropositivity in young, healthy Korean adults.

METHODS

Between March 2009 and February 2010, a total of 5,051 persons from 20 to 49 years of age presenting for a health check-up were included and responded to a questionaire. The seroprevalence of HAV was investigated by measuring immunoglobulin G (IgG) anti-HAV. A total of 984 pairs of cases and age- and sex-matched controls were analyzed for associated socioeconomic factors.

RESULTS

The prevalence of seropositive HAV was 6.2% in the 20 to 29 age range, 33.1% in the 30 to 39 range and 82.4% in the 40 to 49 range (p<0.001). There were no significant differences in any group according to gender. A multivariate analysis for paired cases indicated that HAV seropositivity was significantly higher in the low monthly income (below five million won, approximately 4,300 dollars) group and the Helicobacter pylori (H. pylori)-positive group (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.27-2.14; p<0.001; OR, 1.45; 95% CI, 1.19-1.76; p<0.001, respectively).

CONCLUSIONS

HAV seropositivity in young adults presenting for a health checkup appears to be decreasing, and the prevalence was significantly higher in the low monthly income group and the H. pylori-positive group.