Primary biliary cirrhosis developing in a patient with Crohn's disease during the course of infliximab treatment: the first case in the literature

The causal effects of inflammatory bowel disease on primary biliary cholangitis: A bidirectional two-sample Mendelian randomization study

BACKGROUND

Observational studies have indicated that the incidence of primary biliary cholangitis (PBC) is higher in inflammatory bowel disease (IBD) patients than that in healthy people. However, whether the correlation is causal remains unclear.

METHODS

The genetic associations with IBD were obtained from publicly available genome-wide association studies (GWAS) of European ancestry with 31 665 cases and 33 977 controls, consisting of 17 897 Crohn's disease (CD) and 13 768 ulcerative colitis (UC) cases. The genetic associations with PBC were obtained from a European GWAS with 2764 cases and 10 475 controls. A bidirectional two-sample Mendelian randomization (MR) design was implemented to determine the causal relationship between IBD and PBC. In the forward MR, the IBD was treated as the exposure while the PBC was the exposure in the reverse MR. The inverse-variance-weighted (IVW) method was utilized as the main statistic method, and a series of sensitivity analyses were performed to detect heterogeneity and horizontal pleiotropy.

RESULTS

A total of 99 valid instrumental variables (IVs) were selected for IBD and the number of IVs for PBC was 18. The forward MR analysis indicated that genetically predicted IBD (UC and CD) was significantly associated with an increased risk of PBC (IVW OR = 1.343; 95% CI: 1.220-1.466). Similar casual associations were observed in UC (IVW OR = 1.244; 95% CI: 1.057-1.430) and CD (IVW OR = 1.269; 95% CI: 1.159-1.379). Such results were still consistent in multiple MR methods. The reverse MR analysis implicated that genetic susceptibility to PBC might not alter the risk of IBD (IVW OR = 1.070; 95% CI: 0.984-1.164).

CONCLUSION

Our study found that genetically predicted IBD can increase the risk of PBC while not vice versa in the European population, which may enlighten the aetiology of PBC, together with the IBD patient management.

A Case of Autoimmune Hepatitis/Primary Biliary Cholangitis Overlap Syndrome during Treatment with Brodalumab for Generalized Pustular Psoriasis

Psoriasis is a chronic inflammatory skin disease characterized by accelerated tumor necrosis factor-α (TNF-α) /interleukin (IL) -23/IL-17 axis, epidermal hyperproliferation, and dysregulated differentiation. Psoriasis is occasionally associated with autoimmune liver diseases such as autoimmune hepatitis (AIH) or primary biliary cholangitis (PBC), caused by autoimmunity against hepatocyte- or cholangiocyte-specific autoantigens, respectively. Overlap syndrome is a condition in which patients have features of both AIH and PBC. It has been reported that AIH, PBC, or the overlap syndrome can be triggered by certain drug therapies. A 65-year-old Japanese man developed increased serum levels of aspartate and alanine aminotransferases, and positive anti-nuclear and anti-mitochondrial M2 antibodies, along with neutropenia, at 4 weeks of treatment with an anti-IL-17 receptor A antibody brodalumab for generalized pustular psoriasis. Histological evaluation of the liver revealed interface hepatitis and non-suppurative destructive cholangitis, which is compatible with the overlap syndrome of AIH and PBC. This is the first case of AIH/PBC overlap syndrome during treatment with brodalumab for generalized pustular psoriasis. The relationship between brodalumab and AIH/PBC overlap syndrome should be further elucidated. The risk of autoimmune liver diseases in patients with psoriasis treated with brodalumab should be carefully considered.

Primary biliary cholangitis in patients with inflammatory bowel disease

BACKGROUND & AIMS

Inflammatory bowel diseases (IBD) are associated with various hepatobiliary disorders. There is a strong association for primary sclerosing cholangitis (PSC). Primary biliary cholangitis (PBC), another autoimmune cholestatic liver disease, is not usually associated with IBD. The aim of this study is to report cases of PBC-associated IBD, their clinical features, response to therapy, and long-term outcome.

METHODS

Retrospective analysis of a prospectively collated database identified patients presenting with PBC-associated IBD from 2006 to 2016. PBC has been diagnosed according to accepted criteria, and staged according to Ludwig classification. A magnetic resonance cholangiopancreatography (MRCP) was performed to rule out PSC. Response to ursodeoxycholic acid (UDCA) therapy has been assessed by using the Paris II criteria.

RESULTS

A total of six patients (five females) with PBC-associated IBD were identified. Median age at IBD diagnosis was 44.7 years (range 22.5-48.8). Three had Crohn's disease and three ulcerative colitis. PBC was diagnosed in all after IBD had been diagnosed. All patients presented with cholestasis, all were positive for anti-mitochondrial antibodies. MRCP was normal in all. Liver biopsy was consistent with PBC (stage I in one, stage II in five). One year after initiation of UDCA, all patients responded to therapy.

CONCLUSION

Herein we describe the largest series reported to date of PBC-associated IBD. Although the coexistence of the two conditions is rare, PBC should be considered during the work-up of abnormal liver function tests in patients with IBD.

Increased cholestatic enzymes in two patients with long-term history of ulcerative colitis: consider primary biliary cholangitis not always primary sclerosing cholangitis

Several hepatobiliary disorders have been reported in ulcerative colitis (UC) patients with primary sclerosing cholangitis (PSC) being the most specific. Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, rarely occurs in UC. We present two PBC cases of 67 and 71 years who suffered from long-standing UC. Both patients were asymptomatic but they had increased cholestatic enzymes and high titres of antimitochondrial antibodies (AMA)-the laboratory hallmark of PBC. After careful exclusion of other causes of cholestasis by MRI/magnetic resonance cholangiopancreatography (MRCP), virological and microbiological investigations, a diagnosis of PBC associated with UC was established. The patients started ursodeoxycholic acid (13 mg/kg/day) with complete response. During follow-up, both patients remained asymptomatic with normal blood biochemistry. Although PSC is the most common hepatobiliary manifestation among patients with UC, physicians must keep also PBC in mind in those with unexplained cholestasis and repeatedly normal MRCP. In these cases, a reliable AMA testing can help for an accurate diagnosis.