Characterization of M2 antibodies in asymptomatic Chinese population

Epidemiology and distribution of 207 rare diseases in China: A systematic literature review

Epidemiological data on rare diseases in China are currently limited. The objective of this study was to provide a comprehensive understanding of the prevalence and incidence of rare diseases by systematically analyzing the available epidemiological data. We conducted a comprehensive search of English and Chinese databases, the Incidence and Prevalence Database, the Chinese Rare Disease Guideline, and the Taiwan Health Promotion Administration from 2010 to 2023. We identified the top diseases and regions based on epidemiological data and present the maximum, minimum, and median prevalence and incidence values in tables and forest plots. 1,264 prevalence and incidence data were retrieved from 277 studies, guidelines and official websites, covering 110 rare diseases (53.1%) and 32 regions (94.1%). In terms of geographical regions, incidence or prevalence data were available for 32 regions (94.1%), excluding Tibet Hui Autonomous Region and Macao Special Administrative Region. In terms of rate, 60 and 77 out of 207 diseases (29.0% and 37.2%) had available incidence and prevalence data, respectively. Eight diseases had an incidence rate equal to or greater than that of 1,000 patients per million. The present study provides a comprehensive epidemiological analysis and valuable insights into the prevalence and incidence of rare diseases in China. Our findings underscore the pressing need for sustained drug research and medical support for individuals and families impacted by rare diseases.

The risk of development of primary biliary cholangitis among incidental antimitochondrial M2 antibody-positive patients

Background and Aim

This study investigated the risk of the development of primary biliary cholangitis (PBC) in individuals who were incidentally identified as having positive antimitochondrial antibodies (AMA)-M2.

Materials and Methods

We retrospectively reviewed extractable nuclear antibody (ENA) panel test results to identify the incidental AMA-M2-positive patients. Patients who filled the diagnostic criteria for PBC were excluded. AMA-M2-positive patients were further evaluated by physical examination, liver biochemistry, liver ultrasonography, and transient elastography (TE) and were also closely followed.

Results

We included 48 (n=45, 93% female) individuals with a median age of 49 (range: 20-69) years. The median follow-up duration was 27 months (range: 9-42) after the detection of AMA-M2. Thirty-three (69%) patients had concomitant autoimmune/inflammatory disorders. Twenty-eight (58%) individuals showed seropositivity for ANA, and 21 had (43%) positive AMA. Fifteen (31%) patients developed typical PBC according to the international PBC diagnostic criteria during the follow-up, and five of them (18%) had significant fibrosis (≥8.2 kPA) by TE at the time of PBC diagnosis.

Conclusion

Two-thirds of the incidental AMA-M2-positive patients developed typical features of PBC after a median 27-month follow-up. Our results suggest that AMA-M2 patients should be closely followed up to detect the late development of PBC.

Primary biliary cirrhosis-specific autoantibodies in first degree relatives of Greek primary biliary cirrhosis patients

AIM: To determine the prevalence and significance of primary biliary cirrhosis (PBC)-specific autoantibodies in first-degree relatives (FDRs) of Greek PBC patients.

METHODS: The presence of antimitochondrial antibodies (AMA) and PBC-specific antinuclear antibodies (ANA) were determined using indirect immunofluorescence assays, dot-blot assays, and molecularly based enzyme-linked immunosorbent assays in 101 asymptomatic for liver-related symptoms FDRs of 44 PBC patients. In order to specify our results, the same investigation was performed in 40 healthy controls and in a disease control group consisting of 40 asymptomatic for liver-related symptoms FDRs of patients with other autoimmune liver diseases namely, autoimmune hepatitis-1 or primary sclerosing cholangitis (AIH-1/PSC).

RESULTS: AMA positivity was observed in 19 (only 4 with abnormal liver function tests) FDRs of PBC patients and none of the healthy controls. The prevalence of AMA was significantly higher in FDRs of PBC patients than in AIH-1/PSC FDRs and healthy controls [18.8%, 95% confidence interval (CI): 12%-28.1% vs 2.5%, 95% CI: 0.1%-14.7%, P = 0.01; 18.8%, 95% CI: 12%-28.1% vs 0%, 95% CI: 0%-10.9%, P = 0.003, respectively]. PBC-specific ANA positivity was observed in only one FDR from a PSC patient. Multivariate analysis showed that having a proband with PBC independently associated with AMA positivity (odds ratio: 11.24, 95% CI: 1.27-25.34, P = 0.03) whereas among the investigated comorbidities and risk factors, a positive past history for urinary tract infections (UTI) was also independently associated with AMA detection in FDRs of PBC patients (odds ratio: 3.92, 95% CI: 1.25-12.35, P = 0.02).

CONCLUSION: In FDRs of Greek PBC patients, AMA prevalence is significantly increased and independently associated with past UTI. PBC-specific ANA were not detected in anyone of PBC FDRs.

Update on the epidemiology of primary biliary cirrhosis

The epidemiology of primary biliary cirrhosis was described as early as the 1970s, yet decades later the true frequency of this disease and its associated risk factors are still in question. There has been a wealth of data documenting the various incidence and prevalence rates across the world, demonstrating potential risk factors inherent to geographic differences. Studies that follow primary biliary cirrhosis in a set population over time have offered the most reliable picture of disease frequency. Analysis of clustering effects through region and time has offered valuable information on the complexity of the disease development. Improved epidemiologic surveillance of primary biliary cirrhosis around the world will be necessary to provide definitive evidence on the phenomenon of clustering and its associations with proposed risk factors in the literature.

Prevalence of primary biliary cirrhosis in adults referring hospital for annual health check-up in Southern China

BACKGROUND

Primary biliary cirrhosis (PBC) is an autoimmune liver disease characterized by the presence of anti-mitocondrial autoantibodies (AMA) which has an essential role also for diagnosis. In addition, also some anti-nuclear antibodies (ANA) have been shown to be highly specific PBC. The purpose of this study was to assess the prevalence of PBC among the adults referring hospital for annual health check-up in Southern China by screening sera for PBC-specific autoantibodies.

METHODS

AMA and ANA were screened in 8,126 adults (mean age 44 ± 15 years, 48% females) by indirect immunofluorenscence (IIF). Positive sera were tested by ELISA/immunoblotting for AMA-M2, anti-sp100 and anti-gp210. A diagnosis of PBC was re-assessed six months after the initial testing.

RESULTS

Out of 8,126 individuals 35 were positive for AMA and 79 positive for ANA. Nineteen, 4, and 3 of the subjects positive for AMA and/or ANA showed reactivity for AMA-M2, anti-sp100 or gp210, respectively, further tested with ELISA/immunoblotting. Fourteen in the 39 individuals positive for AMA at IIF, AMA-M2, anti-gp210, or anti-sp100 had abnormal cholestatic liver functional indices. One definite and 3 probable PBC diagnosis could be made in 4 cases including 3 females and 1 male after half a year.

CONCLUSIONS

We found a point prevalence rate of PBC among Southern Chinese adults attending for yearly health check-up of 492 cases per million (95% CI, 128 to 1,093) and 1,558 cases per million (95% CI, 294 to 3,815) for women over 40, a finding similar to prevalence reported in other geographical areas.

Usefulness of liver infiltrating CD86-positive mononuclear cells for diagnosis of autoimmune hepatitis

AIM: Although the pathogenic mechanism underlying autoimmune hepatitis (AIH) remains unclear, the immune system is thought to be critical for the progression of the disease. Cellular immune responses may be linked to the hepatocellular damage in AIH. Recently, much attention has been focused on the critical functions of costimulatory molecules expressed on mononuclear cells in the generation of effective T cell-mediated immune responses. Analysis of costimulatory molecule expressed on mononuclear cells from the patients with AIH may give us insight into the pathogenic mechanism of hepatocellular damage in AIH.

METHODS: Peripheral blood mononuclear cells (PBMC) were taken from the patients with AIH (34 cases) and healthy controls (25 cases). Liver infiltrating mononuclear cells (LIMCs) were taken from the patients with AIH (18 cases), the patient with chronic hepatitis C (CH-C) (13 cases) and the patients with fatty liver (2 cases). Using flow cytometry, the cells were analyzed for the expression of costimulatory molecules, such as CD80, CD86, and CD152 (CTLA-4). The results were compared with clinical data such as the level of gammaglobulin, histological grade, presence or absence of corticosteroids administration and the response to corticosteroids.

RESULTS: The levels of CD80+, CD86+ and CD152+ PBMC were significantly reduced in the patients with AIH as compared with healthy controls. By contrast, those cells were significantly higher in LIMC than in PBMC of the patients with AIH. Especially, the level of CD86+ LIMC showed a marked increase irrespective of the degree of disease activity in the patients with AIH, although CD86+ cells were rarely present in PBMC. The levels of CD86+ cells were present in significantly higher frequency in patients with AIH than in the patients with CH-C. Furthermore, the patients with AIH with high levels of CD86+ LIMC showed good responses to corticosteroids, whereas 2 cases of AIH with low levels of CD86+ LIMC did not respond well.

CONCLUSION: These results suggest that LIMC over-expressing costimulatory molecules such as CD80 and CD86 appears to play a role in the pathogenesis of AIH. Especially, CD86 molecule expressed on the LIMC may be useful for the diagnosis of AIH and for the prediction of the therapeutic effects of corticosteroids on AIH.

A retrospective study on clinical features and prognostic factors of biopsy-proven primary biliary cirrhosis in Chinese patients

OBJECTIVES

Though extensive research has been performed on primary biliary cirrhosis (PBC) in Caucasian patients, little is known about the disease in the Asian population.

PATIENTS AND METHODS

This was a retrospective study of Chinese patients with biopsy-proven PBC. Electronic records of results from all liver biopsies (n = 1,021) performed between January 1996 and April 2004, together with records of patients labeled as "biliary cirrhosis," were retrieved. Patients with biopsy-proven PBC were identified, and their medical notes were reviewed. The demographic, clinical, biochemical, and histological parameters of these patients were analyzed for mortality predictors.

RESULTS

Thirty-nine patients with biopsy-proven PBC and a median follow-up of 44 (range: 5-114) months were identified. Twelve patients (30.8%) were asymptomatic at diagnosis. The patients were approximately equally divided into one-thirds at stages I, II, and III of the histological disease. Hepatic decompensation or hepatocellular carcinoma developed in 14 (35.9%) patients during the follow-up period. The overall 5-yr survival probability was 81.4%. Hypoalbuminemia was found to be the only independent predictor of mortality on multivariate analysis (hazard ratio = 0.50 per 1 g/L increase, 95% CI 0.30-0.84, p= 0.008). Using the median serum albumin level as the cutoff, the 5-yr survival probability was significantly higher for patients with serum albumin levels >35 g/L than for those with serum albumin levels < or =35 g/L (100% vs 69%, p= 0.007). No significant difference was found when baseline serum albumin was compared with the Mayo Risk Score and the model for end-stage liver disease (MELD) score for prediction of patient survival (p= 0.68) and death (p= 0.12) at 5 yr.

CONCLUSIONS

In this longitudinal cohort study of biopsy-proven PBC with up to 9 yr of follow-up, we found that Chinese patients with PBC had significant morbidity and mortality. Hypoalbuminemia at presentation was an independent and strong predictor of mortality.