Primary sclerosing cholangitis associated with lupus nephritis: a rare association

Causal relationship between primary sclerosing cholangitis and systemic lupus erythematosus: a bidirectional Mendelian randomization study

BACKGROUND

Observational studies have found a link between two autoimmune diseases, namely, primary sclerosing cholangitis (PSC) and systemic lupus erythematosus (SLE). However, the relationship remains unclear.

METHODS

Bidirectional Mendelian randomization (MR) analysis and statistical methods, including inverse variance weighting, weighted median, and MR-Egger tests, were performed using data from genome-wide association studies to detect a causal relationship between PSC and SLE. Sensitivity analyses were subsequently performed to assess the robustness of the results. Univariate MR methods were also investigated.

RESULTS

Results of MR analysis suggested that PSC was associated with an increased risk for SLE (odds ratio: 1.33, 95% confidence interval: 1.10-1.61, P=0.0039) However, SLE had no significant causal relationship with PSC.

CONCLUSION

Results of MR analysis revealed that patients with PSC were at an increased risk for SLE, which provides new insights into the relationship between these two autoimmune diseases.

Identifying the genetic association between systemic lupus erythematosus and the risk of autoimmune liver diseases

BACKGROUND

Previous studies on the relationship between systemic lupus erythematosus (SLE) and autoimmune liver diseases (AILDs) are inconclusive. Therefore, we employed Mendelian randomization (MR) to explore the causal associations between SLE and AILDs.

METHODS

A two-sample MR analysis was performed using summary-level statistics sourced from genome-wide association study (GWAS) datasets. Inverse-variance weighting (IVW), MR‒Egger, and weighted median (WM) were further supported by several sensitivity analyses.

RESULTS

We detected causal genetic associations between SLE and primary biliary cholangitis (PBC) (odds ratio (OR) = 1.31, 95% CI = 1.15-1.51, P < 0.01; adjusted OR = 1.63, 95% CI = 1.39-1.90, P < 0.01) and between SLE and primary sclerosing cholangitis (PSC) (OR = 1.09, 95% CI = 1.01-1.08, P = 0.03; adjusted OR = 1.10, 95% CI = 1.00-1.21, P = 0.04). No causal association was found between SLE and autoimmune hepatitis.

CONCLUSIONS

We are the first to use MR analysis to explore the causal relationships between SLE and various AILDs, revealing an increased risk of PBC and PSC in individuals with SLE.

Autoimmune liver diseases in systemic rheumatic diseases

Systemic rheumatic diseases (SRDs) are chronic, inflammatory, autoimmune disorders with the presence of autoantibodies that may affect any organ or system. Liver dysfunction in SRDs can be associated with prescribed drugs, viral hepatitis, alternative hepatic comorbidities and coexisting autoimmune liver diseases (AILDs), requiring an exclusion of secondary conditions before considering liver involvement. The patterns of overlap diseases depend predominantly on genetic determinants with common susceptible loci widely distributing in both disorders. In AILDs, it is important to identify the overlapping SRDs at an early stage since such a coexistence may influence the disease course and prognosis. Commonly co-occurring SRDs in AILDs are Sjögren syndrome (SS), rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) in autoimmune hepatitis (AIH), and SS, RA or systemic sclerosis in primary biliary cholangitis. Owing to different disease complications and therapies, it is imperative to differentiate between SLE liver involvement and SLE-AIH overlap disease. Therapeutic options can be personalized to control coexisting conditions of liver autoimmunity and rheumatic manifestations in AILD-SRD overlap diseases. The collaboration between hepatologists and rheumatologists can lead to significant advances in managing such a complex scenario. In this review, we provide a comprehensive overview on coexisting AILDs in different SRDs and the therapeutic approach in managing these overlap diseases.

Towards a practical management of fatigue in systemic lupus erythematosus

Significant fatigue is reported by two-thirds of patients with SLE and severe fatigue by one-third. The assessment and treatment of fatigue remains a major challenge in SLE, especially in patients with no disease activity. Here, we suggest a practical algorithm for the management of fatigue in SLE. First, common but non–SLE-related causes of fatigue should be ruled out based on medical history, clinical and laboratory examinations. Then, presence of SLE-related disease activity or organ damage should be assessed. In patients with active disease, remission is the most appropriate therapeutic target while symptomatic support is needed in case of damage. Both anxiety and depression are major independent predictors of fatigue in SLE and require dedicated assessment and care with psychological counselling and pharmacological intervention if needed. This practical algorithm will help in improving the management of one the most common and complex patient complaints in SLE.

Challenge of liver disease in systemic lupus erythematosus: Clues for diagnosis and hints for pathogenesis

Systemic lupus erythematosus (SLE) encompass a broad spectrum of liver diseases. We propose here to classify them as follows: (1) immunological comorbilities (overlap syndromes); (2) non-immunological comorbilities associated to SLE; and (3) a putative liver damage induced by SLE itself, referred to as "lupus hepatitis". In the first group, liver injury can be ascribed to overlapping hepatopathies triggered by autoimmune mechanisms other than SLE occurring with higher incidence in the context of lupus (e.g., autoimmune hepatitis, primary biliary cirrhosis). The second group includes non-autoimmune liver diseases, such as esteatosis, hepatitis C, hypercoagulation state-related liver lesions, hyperplasic parenchymal and vascular lesions, porphyria cutanea tarda, and drug-induced hepatotoxicity. Finally, the data in the literature to support the existence of a hepatic disease produced by SLE itself, or the occurrence of a SLE-associated prone condition that increases susceptibility to acquire other liver diseases, is critically discussed. The pathological mechanisms underlying each of these liver disorders are also reviewed. Despite the high heterogeneity in the literature regarding the prevalence of SLE-associated liver diseases and, in most cases, lack of histopathological evidence or clinical studies large enough to support their existence, it is becoming increasingly apparent that liver is an important target of SLE. Consequently, biochemical liver tests should be routinely carried out in SLE patients to discard liver disorders, particularly in those patients chronically exposed to potentially hepatotoxic drugs. Diagnosing liver disease in SLE patients is always challenging, and the systematization of the current information carried out in this review is expected to be of help both to attain a better understanding of pathogenesis and to build an appropriate work-up for diagnosis.

Investigations and management of gastrointestinal and hepatic manifestations of systemic lupus erythematosus

Gastrointestinal (GI) manifestations of systemic lupus erythematosus (SLE) are protean. Any part of the GI tract and the hepatobiliary system can be involved. Up to two-third of SLE patients develop GI symptoms at some stage of their illnesses. Clinical presentations of GI lupus are non-specific and can be difficult to differentiate from infective, thrombotic, therapy-related and non-SLE etiologies. Clinical acumen and appropriate endoscopic, biopsy and imaging procedures are essential for establishing the correct diagnosis. Acute abdominal pain in SLE patients can herald an intra-abdominal catastrophe and should be evaluated promptly. Surgical intervention should be instituted without delay if conservative management fails or when there is clinical or radiological suspicion of visceral perforation or intra-abdominal collections.