Autoantibody profiles associated with morbidity and mortality in scleroderma renal crisis

Autoantibodies as putative biomarkers and triggers of cell dysfunctions in systemic sclerosis

PURPOSE OF REVIEW

Antinuclear autoantibodies represent a serological hallmark of systemic sclerosis (SSc), with anticentromere, antitopoisomerase-I, and anti-RNA polymerase III antibodies routinely assessed for diagnosis, clinical subset classification, and prognosis. In addition, an increasing number of autoantibodies have been demonstrated to play a pathogenic role by mediating different SSc manifestations. This review aims to give an overview on autoantibodies as putative biomarkers in SSc and discuss their possible pathogenic role as triggers of cell dysfunctions.

RECENT FINDINGS

Over the years, different autoantibodies have been proposed as biomarkers aiding in diagnosis, disease subtype classification, disease progression prediction, organ involvement, as well as in understanding treatment response. Increasing literature also indicates functional autoantibodies as direct contributors to SSc pathogenesis by exerting agonistic or antagonistic activities on their specific cognate targets.

SUMMARY

In SSc, search and validation of novel autoantibodies with higher diagnostic specificity and more accurate predictive values are increasingly needed for early diagnosis and specific follow-up, and to define the best therapeutic option according to different disease subsets. Moreover, since autoantibodies are also emerging as functional pathogenic players, a better unraveling of their possible pathomechanisms becomes essential to identify new targets and develop promising therapeutic agents able to neutralize their effects.

Scleroderma renal crisis, an increasingly rare but persistently challenging condition: a retrospective cohort study

Objective

Scleroderma renal crisis (SRC) is associated with high morbidity and mortality and there remain unmet needs regarding early identification and treatment. We aimed to assess risk factors for and the outcomes of SRC at a large Australian tertiary hospital.

Methods

Seventeen incident SRC cases were diagnosed between 2012 and 2022. Demographic, SSc manifestations and treatment data were extracted. Using data from the Australian Scleroderma Cohort Study (n = 483), logistic regression analysis was performed to identify risk factors for SRC.

Results

The prevalence of SRC was 3.52%. The median SSc disease duration at SRC onset was 2 years [interquartile range (IQR) 1-4]. Peak creatinine occurred at a median of 11 days (IQR 5-14) post-SRC diagnosis, with a median peak creatinine of 144 µmol/l (IQR 86-306). Nine (52.94%) SRC patients had evidence of acute neurologic and/or cardiac complications. Acute haemofiltration was required in 3 (17.65%) patients. Over the follow-up period, 7 (41.18%) SRC patients died 2.75 years (IQR 0.74-7.25) after SRC onset. Patients with SRC were more likely to be male [odds ratio (OR) 9.73 (95% CI 3.57, 26.56)], have diffuse disease [OR 23.16 (95% CI 5.22, 102.80)] and have antibodies to Scl70 [OR 3.34 (95% CI 1.24, 9.04)] or RNA polymerase III (RNAPIII) [OR 5.15 (95% CI 1.91, 13.89)].

Conclusion

SRC is an uncommon manifestation, but outcomes remain poor. A significant proportion of patients presenting with SRC in Australia are positive for Scl70 or RNAPIII antibody. Despite relatively low peak serum creatinine and rates of renal replacement therapy, SRC was still associated with significant mortality.

[High anti-topoisomerase-1 autoantibodies levels are associated with the extension of skin fibrosis and vascular progression in patients with systemic sclerosis]

BACKGROUND

Anti-centromere antibodies, anti-topoisomerase-1 antibodies (ATA), and anti-RNA-polymerase III antibodies are three Systemic Sclerosis (SSc)-specific autoantibodies. Their detection is helpful in determining the prognosis. We aimed to evaluate whether ATA levels were associated with disease severity at diagnosis or disease progression during follow-up in ATA positive patients.

METHODS

We conducted a single-centre French retrospective observational study, between 2014 and 2021. ATA positive patients fulfilling the ACR/EULAR 2013 classification criteria for SSc with a minimal follow-up of 1 year and 2 ATA dosages were included. SSc patients with high IgG ATA levels at baseline (>240IU/mL) were compared with SSc patients with low levels (≤240IU/mL), at inclusion and at 1 and 3 years. A variation of at least 30 % of ATA levels was considered significant.

RESULTS

Fifty-nine SSc patients were included and analysed. There was a predominance of women and of patients with diffuse interstitial lung disease. Patients with high ATA levels exhibited a higher skin sclerosis assessed by the modified Rodnan skin score (P=0.0480). They had a lower carbon monoxide transfer coefficient (P=0.0457), a lower forced vital capacity (FVC) (P=0.0427) and more frequently had a FVC under 80 %, when compared to patients with low ATA levels (P=0.0423). Initial high ATA levels were associated with vascular progression at one year (21.95 % vs. 0 %; P=0.0495).

CONCLUSION

ATA levels are associated with skin sclerosis and vascular progression in SSc. Beyond the detection of ATA, quantifying this autoantibody might be of interest in predicting disease severity and prognosis in SSc.

Severe immune thrombocytopenia in two patients with systemic sclerosis

Thrombocytopenia in the context of systemic sclerosis (SSc) is rare. It should primarily raise the possibility of scleroderma renal crisis. Immune thrombocytopenia (ITP) is another cause of low platelets that is common in systemic lupus erythematosus, but tremendously rare in patients with SSc. We herein report two cases of severe ITP in patients with SSc. The first case is a 29-year-old woman with very low platelet counts (2×109/L) that did not increase despite receiving corticosteroids, intravenous immunoglobulins (IVig), rituximab and romiplostim. Because of a symptomatic acute subdural haematoma, emergency splenectomy was performed and subsequently platelet counts normalised without neurological sequelae. The second case is a 66-year-old woman in whom self-limited mild epistaxis revealed low platelet counts (8×109/L). The patient did not improve after the use of IVig and corticosteroids. Secondarily rituximab and romiplostim normalised the platelet counts after 8 weeks. To the best of our knowledge this is the first reported case of severe ITP in a patient with diffuse cutaneous SSc and anti-topoisomerase antibodies.

Comprehensive autoantibody profiles in systemic sclerosis: Clinical cluster analysis

Background

Systemic sclerosis (SSc) belongs to the group of connective tissue diseases and is associated with the occurrence of disease-specific autoantibodies. Although it is still controversial whether these antibodies contribute to pathogenesis, there are new insights into the development of these specific antibodies and their possible pathophysiological properties. Interestingly, they are associated with specific clinical manifestations, but for some rarer antibodies this association is not fully clarified. The aim of this study is a comprehensive analysis of the serum autoantibody status in patients with SSc followed by correlation analyses of autoantibodies with the clinical course of the disease.

Methods

Serum from SSc patients was analyzed using a line blot (EUROLINE, EUROIMMUN AG) for SSc-related autoantibodies. Autoantibodies to centromere, Topo-1, antimitochondrial antibodies (AMA) M2 subunit, angiotensin II type 1 receptors (AT1R) and endothelin-1 type-A-receptors (ETAR) were also determined by ELISA. We formed immunological clusters and used principal components analysis (PCA) to assign specific clinical characteristics to these clusters.

Results

A total of 372 SSc patients were included. 95.3% of the patients were antinuclear antibody positive and in 333 patients at least one SSc specific antibody could be detected. Four immunological clusters could be found by PCA. Centromere, Topo-1 and RP3 all formed own clusters, which are associated with distinct clinical phenotypes. We found that patients with an inverted phenotype, such as limited cutaneous SSc patients within the Topo-1 cluster show an increased risk for interstital lung disease compared to ACA positive patients. Anti-AT1R and anti-ETAR autoantibodies were measured in 176 SSc patients; no association with SSc disease manifestation was found. SSc patients with AMA-M2 antibodies showed an increased risk of cardiovascular events.

Conclusion

In our in large cluster analysis, which included an extended autoantibody profile, we were able to show that serologic status of SSc patients provides important clues to disease manifestation, co-morbidities and complications. Line blot was a reliable technique to detect autoantibodies in SSc and detected rarer autoantibodies in 42% of our patients.

Management of scleroderma renal crisis with left ventricular diastolic dysfunction in a resource-limited setting: A rare case report

Scleroderma renal crisis with left ventricular diastolic dysfunction can lead to significant mortality. We presented the case of a 32-year-old female with anuria for 2 days. On further inquiry, she had joint pain, difficulty turning her head sidewise, and associated difficulty in finger movement. Also, hyperpigmentation with superimposed hypopigmentation was reported, which reduced during her pregnancy and worsened post-partum. Her family history suggested similar complaints in her mother. In addition, she had a blurring of vision. She had hypertension, microangiopathic hemolytic anemia, deranged renal function, and retinopathy on ophthalmologic examination. Radiological investigations revealed pulmonary edema, pleural effusion, and left ventricular diastolic dysfunction. Hence, a diagnosis of scleroderma renal crisis complicated by left ventricular diastolic dysfunction was made. She was managed conservatively using anti-hypertensive medications and hemodialysis, which resulted in gradual improvement. Our case highlighted the management approach to this rare presentation with anti-hypertensives and hemodialysis in a resource-limited setting.

Scleroderma autoantibodies in guiding monitoring and treatment decisions

PURPOSE OF REVIEW

One of the key clinical challenges of systemic sclerosis (SSc) is diversity in clinical presentation, organ involvement and disease progression. Antinuclear autoantibodies (ANA) are central to the diagnosis of SSc. ANA specificities associated with distinct clinical patterns of organ and skin involvement. Understanding of the molecular differences and pathogenesis of scleroderma has helped further inform clinical acumen. Here, we provide an update on ANA on clinical profiling, management and future direction of SSc.

RECENT FINDINGS

There has been further development in delineating clinical patterns in ANA, genetic susceptibility and antigen triggers predisposing to ANA subtypes. Sub-group analysis of recent clinical trials shows differing treatment responses to novel therapeutics.

SUMMARY

ANA subtyping is likely to be firmly embedded into future classification systems. Beyond informing current management and monitoring of scleroderma patients, ANA subsets have implication on future research and clinical trial design.