[Drug-induced lupus]

Mendelian randomization study on causal association of FAM210B with drug-induced lupus

OBJECTIVE

Due to the complexity of drug-induced lupus (DIL) pathogenesis, more susceptibility factors need to be discovered. FAM210B is a new mitochondrial protein whose function has not been fully elucidated. This study will explore whether there is a correlation between FAM210B and the risk of DIL.

METHODS

At first, we extracted three FAM210B genetic variants from the GTEx database (n = 948), and extracted their corresponding genome-wide association study (GWAS) summary statistics from DIL (101 DIL cases and 218691 controls). Then, we performed a Mendelian randomization (MR) study to evaluate the causal association of the expression of FAM210B with DIL using inverse-variance weighted (IVW), the weighted median, MR-Egger, and MR-PRESSO test.

RESULTS

We successfully extracted three FAM210B single-nucleotide polymorphisms (SNPs) (rs116032784, rs34361943 and rs33923703) from the GTEx_Analysis_v8_eQTL data that can reduce FAM210B expression. The results of the MR analysis showed that genetically reduced expression of FAM210B was significantly associated with increased risk of DIL in European ancestry based on the IVW method (β = 1.037, p = 0.001, odds ratio [OR] = 2.821, 95% confidence interval [CI]:1.495-5.322).

CONCLUSION

MR analysis showed a causal relationship between FAM210B expression and the risk of DIL disease. Our results suggested that FAM210B may be a marker that can mark susceptibility of DIL in the future. It provides evidence for the study of DIL, but its specific mechanism of action in DIL needs to be further studied. Key Points •This is the first MR analysis to examine the association between FAM210B and DIL. •The findings of this study suggested that reduced FAM210B expression is associated with the increased risk of DIL. •FAM210B may be a marker that can mark susceptibility of DIL in the future.

Recommendations for the use of anti-dsDNA autoantibodies in the diagnosis and follow-up of systemic lupus erythematosus - A proposal from an expert panel

Anti-dsDNA autoantibodies are listed as one of the classification criteria for systemic lupus erythematosus (SLE) and are relatively effective indicators for monitoring disease activity and treatment response. Therefore, clinicians rely on them to diagnose and adjust medication and treatment strategies for SLE patients. However, the use of anti-dsDNA antibodies is not free from controversy. Part of this controversy stems from the fact that anti-dsDNA antibodies are found in several disorders, besides SLE. In addition to this, anti-dsDNA antibodies are a heterogeneous group of antibodies, and their determination still lacks proper standardization. Moreover, anti-dsDNA testing specificity and diagnostic performance change depending on the population under study. These and other issues result in inconsistency and encumber the clinical use of anti-dsDNA antibodies. A panel of medical laboratory and clinical experts on SLE discussed such issues based on their clinical experience in a first meeting, establishing a series of recommendations. The proceedings of this first meeting, plus an exhaustive review of the literature, were used to compose a paper draft. The panel subsequently discussed and refined this draft in a second meeting, the result of which is this paper. This document is relevant to clinical laboratories as it guides to improving diagnosis and monitoring of SLE. Simultaneously, it will help laboratories compile more informative reports, not limited to a mere number. It is also relevant to clinical doctors who wish to better understand laboratory methods so that they can do a more efficient, better-aimed laboratory test ordering.

Severe lupus induced by the tumor necrosis factor-alpha inhibitor Anbainuo: a case report

In rare cases, clinical inhibitors of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) can induce symptoms of lupus erythematosus (drug-induced lupus, DIL), but this adverse response usually resolves rapidly upon drug withdrawal. We report the case of a 25-year-old Asian woman with rheumatoid arthritis exhibiting severe prolonged DIL even after the termination of TNF-α inhibitor treatment. The patient had been treated intermittently using Traditional Chinese Medicine for 11 years, but this therapy failed to effectively control her clinical symptoms. Subsequently, methotrexate and hydroxychloroquine were prescribed, but a reduced white blood cell count was detected. Finally, the TNF-α inhibitor Anbainuo was prescribed. However, after 2 months of treatment, the patient exhibited elevated serum creatinine, anti-double-stranded DNA (+++), anti-nuclear antibody (1:1000), and urine protein (+++) accompanied by buccal erythema, hair loss, and hand shaking, consistent with Anbainuo-induced lupus, lupus nephritis, and lupus encephalopathy. Moreover, her serum creatinine level remained high after Anbainuo withdrawal and prolonged steroid and immunosuppressive therapy. Careful and sustained monitoring for adverse reactions to Anbainuo (and other TNF-α inhibitors) is recommended.

Clinical Characteristics of Hydralazine-induced Lupus

Introduction The use of hydralazine has been associated with the development of lupus erythematosus and lupus-like syndromes. We performed this retrospective study to identify clinical characteristics of individuals who developed hydralazine-induced lupus. Material and methods We performed a single-center retrospective review of seven individuals who had a diagnosis of hydralazine-induced lupus by International Classification of Diseases, Ninth Revision (ICD9) code and were on hydralazine prior to their diagnosis. Clinical and laboratory data were obtained from a review of the medical record up to 12-month follow-up. Results Of the seven individuals with hydralazine-induced lupus, five were Caucasian (71%) and two were African-American. The mean age at the time of diagnosis was 62 years. Four (57%) were male. The majority of individuals were exposed to hydralazine for more than 12 months (83%). Four individuals had biopsy-proven lupus nephritis and four individuals had cardiopulmonary and skin involvement. Six patients were positive for antinuclear antibody (ANA) with a homogenous pattern, and five of those were positive for anti-histone antibody. Additionally, positive anti-double-stranded DNA (anti-dsDNA) antibody, anti-cardiolipin antibodies, low complements, positive lupus anticoagulant, and leukopenia were seen in 42% of our cohort. Of the five individuals in whom anti-myeloperoxidase (MPO) antibody was strongly positive, all had renal involvement defined by an elevated creatinine with three having biopsy-proven lupus nephritis. Three other individuals with MPO positivity had concurrent cardiopulmonary and skin involvement. Four individuals were positive for anti-proteinase 3 (PR3) antibody, three of whom were strongly positive with renal involvement defined by an elevated creatinine with two having biopsy-proven lupus nephritis. The level of anti-dsDNA antibody and anti-PR3 antibody normalized at three months while anti-MPO antibody took 12 months to normalize following cessation of hydralazine. When checked, low complement component 3 (C3) and anti-histone antibody persisted past 12 months. In addition to the withdrawal of hydralazine, six individuals were treated with hydroxychloroquine and five with mycophenolate mofetil. Three of four individuals with renal involvement received plasmapheresis and two received cyclophosphamide and hemodialysis. Conclusion Hydralazine can aggravate and unmask incipient lupus. Since the presentation can be varied, early recognition of symptoms is critical. Precautions should be taken before initiating this medication in individuals with certain risk factors. Once diagnosed, potential serological findings such as a positive anti-MPO/anti-PR3 antibody could predict more severe manifestations such as pulmonary-renal complications.

Drug-induced lupus erythematosus: an update on drugs and mechanisms

PURPOSE OF REVIEW

Rapid introduction of newly developed drugs in the absence of clear understanding of the pathophysiologic mechanisms behind drug-induced lupus erythematosus (DILE) can sometimes make DILE difficult to recognize in clinical practice. The purpose of this review is to summarize drugs most recently reported to be involved in DILE and discuss the current landscape of diverse mechanisms involved.

RECENT FINDINGS

A large number of proton pump inhibitor (PPI)-induced subacute cutaneous lupus erythematosus cases have been reported, suggesting a shift over time in the spectrum of drugs implicated in DILE. Twenty-two articles comprising 29 DILE case reports published within the last 2 years are summarized in this review, including 12 (41.4%) systemic DILE. Antitumor necrosis factor (anti-TNF) drugs were the most frequently (41.7%) reported to introduce systemic DILE in these cases. Chemotherapeutic drugs were the most common drug class (54.5%) involved in subacute cutaneous lupus erythematosus, with an observed higher incidence in female patients. Enhanced neutrophil extracellular trap (NET) formation induced by procainamide and hydralazine could be a new mechanism contributing to the pathogenesis of DILE.

SUMMARY

The list of drugs implicated in triggering DILE is expanding as new drugs with novel mechanisms of action are being developed. It is important to recognize culprit drugs that may induce lupus erythematosus, as discontinuation usually results in improvement of drug-induced manifestations. Characterizing the mechanisms involved might help better understand the cause of idiopathic autoimmunity.

Autoantibodies in psoriatic patients treated with anti-TNF-α therapy

BACKGROUND

TNF-α inhibitors have been associated with induction of autoantibodies and autoimmune diseases. We retrospectively evaluated the incidence of autoantibodies ANA, ENA, anti-dsDNA, the occurrence of clinical symptoms and possibly related treatment failure.

PATIENTS AND METHODS

The titers of ANA, ENA and anti-dsDNA were evaluated from blood samples every six months in 128 patients receiving a TNF-α inhibitor (adalimumab, etanercept, infliximab).

RESULTS

Overall 37% of 128 patients treated with anti-TNF-α drug developed autoantibodies, mostly induced by infliximab; 48.48 % of patients who received infliximab presented autoantibodies. One patient developed a drug-induced lupus erythematosus. Forty-five patients were switched to one or more additional TNF-α inhibitors and 25 developed autoantibodies.

CONCLUSIONS

An increased autoantibody titer is not predictive of treatment failure; particular attention to all phenomena suggestive for autoimmunity is needed in patients with a positive autoantibody titer. Further studies are needed to clarify the role of autoantibodies during anti-TNF- α therapy.

Drug-induced lupus: Including anti-tumour necrosis factor and interferon induced

Drug-induced lupus erythematosus is defined as a syndrome with clinical and serological features similar to systemic lupus erythematosus that is temporally related to continuous drug exposure and which resolves after discontinuation of this drug. More than 90 drugs, including biological modulators such as tumour necrosis factor-α inhibitors and interferons, have been identified as likely ‘culprits’. While there are no standard diagnostic criteria for drug-induced lupus erythematosus, guidelines that can help to distinguish drug-induced lupus erythematosus from systemic lupus erythematosus have been proposed and several different patterns of drug-induced lupus erythematosus are emerging. Distinguishing drug-induced lupus erythematosus from systemic lupus erythematosus is important because the prognosis of drug-induced lupus erythematosus is usually good when the drug is withdrawn. This review discusses the differences between drug-induced lupus erythematosus and systemic lupus erythematosus, the mechanisms of action of drug-induced lupus erythematosus and drugs that are usually associated with drug-induced lupus erythematosus, with particular focus on the biological treatments.