Renal involvement in systemic sclerosis

Acute Kidney Injury in Systemic Sclerosis Beyond Scleroderma Renal Crisis: A Case-Control Study

BACKGROUND AND OBJECTIVES

Renal involvement in systemic sclerosis remains a significant concern with the focus often centered on scleroderma renal crisis (SRC). However, the broader spectrum of renal manifestations, beyond SRC, remains underrecognized. In our case-control analysis, we describe other causes, risk factors, and renal outcomes of acute kidney injury (AKI) in systemic sclerosis other than SRC.

METHODS

Patients diagnosed with SSC, with and without AKI, between 2017 and 2023 at Albany Medical Center, were included in the case-control study using International Classification of Diseases , 10th Revision codes and electronic medical records. Patients with SRC were carefully excluded. Data were collected and compared between AKI and non-AKI groups for patients' demographics, clinical characteristics, and baseline treatment. Additionally, data were collected for baseline, peak, and follow-up creatinine, etiology of AKI, treatment, and outcomes. Statistical analysis was performed using R (version 4.3.0) and Minitab (V19). Categorical variables were presented as frequencies/percentages, and continuous variables as means/standard deviations. Associations between categorical variables were assessed by χ 2 test and Fisher exact test. Odds ratios and 95% confidence intervals were calculated using binary logistic regression to separately assess the effect of each independent variable on the odds of AKI. Statistical significance was set at p < 0.05.

RESULTS

A total of 74 cases were identified. Out of these 74 cases, 27 had AKI and 47 did not have AKI. Out of the 27 AKI cases, 4 with SRC were excluded. Advanced age, chronic kidney disease, and heart failure were identified as risk factors for AKI development. The predominant cause of AKI was prerenal etiology, accounting for 47.8% (n = 11) of cases. This was followed by cardiorenal syndrome and acute tubular necrosis, accounting for 21.7% and 17.3% of the cases, respectively. Most of the cases with AKI had complete renal recovery 78% (n = 18), whereas 17% (n = 4) had progression of the underlying chronic kidney disease. One patient progressed to end-stage renal disease requiring hemodialysis.

CONCLUSIONS

This analysis highlights the risk factors and variable clinicopathological courses of renal involvement in patients with scleroderma. This may range from mild AKI with good prognosis to life-threatening SRC.

Late-age onset systemic sclerosis-clinical and serological characteristics

The clinical course and serological profile of the late-age onset systemic sclerosis (LAO SSc) and the early-age onset SSc (EAO SSc) was compared. The study enrolled 157 patients that fulfilled the American College of Rheumatology (ACR)/European League against Rheumatism (EULAR) classification criteria for systemic sclerosis (SSc). Among them, 69 had diffuse cutaneous SSc (dcSSc) and 88 limited cutaneous SSc (lcSSc). Within this population, 39 patients developed the disease over the age of 60 years old (LAO SSc) and 118 prior to that age (EAO SSc). The subtype of SSc, the incidence of internal organ involvement, the prevalence of malignancy, mortality, and serological profile were compared between both groups. The LAO SSc was observed in 39 of total 157 patients with SSc and exhibited a notably higher prevalence of pulmonary arterial hypertension (p = 0.014), heart involvement (p = 0.0014), and renal involvement (p = 0.0002). The occurrence of arthralgias was less common in the LAO SSc group (p = 0.02) than in the EAO SSc group. Furthermore, in the LAO SSc group, the prevalence of anti -RNA polymerase III antibodies (p = 0.008) and antiPM/Scl antibodies (p = 0.048) were significantly lower than in the EAO SSc group. On the other hand, higher anti-Th/To antibody levels (p = 0.014) were recorded in the LAO SSc group. Approximately 25% of SSc patients experienced a delayed onset of the disease after the age of 60 years old. Some clinical and serological features of late-onset SSc were markedly different from that in early-onset disease. Particularly noteworthy is the fact that involvement of internal organs such as heart and kidneys, as well as pulmonary arterial hypertension were much more often observed among patients with LAO SSc which in our suggestion may be referred to age-related co-morbidities. Key Points • Significant differences in clinical and serological profile of the disease were found between late-age onset (LAO) and early-age onset (EAO) SSc. • Incidence of dcSSc as well as prevalence of anti-RNA polymerase III and anti-PM/Scl antibodies were found to be lower in patients over 60 years old compared to those before 60, but regardless of the age of the disease onset. • Internal organ morbidity, notably pulmonary arterial hypertension, renal impairment and heart disease were significantly more common in elder SSc patients as well as in those with late disease onset. • These findings may suggest an impact of age-related co-morbidities on the course of late-age onset SSc.

Neurological, cardiac, musculoskeletal, and renal manifestations of scleroderma along with insights into its genetics, pathophysiology, diagnostic, and therapeutic updates

Background

Scleroderma, also referred to as systemic sclerosis, is a multifaceted autoimmune condition characterized by abnormal fibrosis and impaired vascular function. Pathologically, it encompasses the persistent presence of inflammation, abnormal collagen buildup, and restructuring of blood vessels in various organs, resulting in a wide range of clinical symptoms. This review incorporates the most recent scientific literature on scleroderma, with a particular emphasis on its pathophysiology, clinical manifestations, diagnostic approaches, and treatment options.

Methodology

A comprehensive investigation was carried out on numerous databases, such as PubMed, MEDLINE, Scopus, Web of Science, and Google Scholar, to collect pertinent studies covering diverse facets of scleroderma research.

Results

Scleroderma presents with a range of systemic manifestations, such as interstitial lung disease, gastrointestinal dysmotility, Raynaud's phenomenon, pulmonary arterial hypertension, renal complications, neurological symptoms, and cardiac abnormalities. Serological markers, such as antinuclear antibodies, anti-centromere antibodies, and anti-topoisomerase antibodies, are important for classifying diseases and predicting their outcomes.

Discussion

The precise identification of scleroderma is crucial for promptly and correctly implementing effective treatment plans. Treatment approaches aim to improve symptoms, reduce complications, and slow down the progression of the disease. An integrated approach that combines pharmacological agents, including immunosuppressants, endothelin receptor antagonists, and prostanoids, with nonpharmacological interventions such as physical and occupational therapy is essential for maximizing patient care.

Conclusion

Through the clarification of existing gaps in knowledge and identification of emerging trends, our goal is to improve the accuracy of diagnosis, enhance the effectiveness of therapeutic interventions, and ultimately enhance the overall quality of life for individuals suffering from scleroderma. Ongoing cooperation and creative research are necessary to advance the field and achieve improved patient outcomes and new therapeutic discoveries.

Protein profiling in systemic sclerosis patients with different pulmonary complications using proteomic antibody microarray

BACKGROUND

Pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD) are leading causes of systemic sclerosis (SSc)-related death. In this study, we aimed to identify biomarkers for detecting SSc pulmonary complications that are mild and in the early stages to improve the prognosis.

METHODS

We screened for serum biomarkers using a proteomic antibody microarray that simultaneously assessed 1000 proteins. Differentially expressed proteins were further verified using ELISA. Finally, we performed a correlation analysis using clinical data.

RESULTS

We identified 125 differentially expressed proteins, of which calcitonin, sclerostin (SOST), CD40, and fibronectin were selected for further verification. Serum calcitonin and SOST levels were significantly elevated in all SSc pulmonary complication subgroups, whereas serum calcitonin levels were higher in the SSc with PAH subgroup than in the SSc without PAH and ILD subgroup. Serum SOST levels were possibly associated with the presence of ILD and positively related to the presence of cardiac and gastrointestinal involvement. Serum CD40 and calcitonin levels appeared to be positively related to the presence of renal involvement, and serum calcitonin was also positively related to the presence of gastrointestinal involvement.

CONCLUSIONS

This study indicated that serum calcitonin and SOST levels may be promising biomarkers for SSc-related PAH and ILD, respectively. Further research is needed to verify this result and understand the underlying mechanisms.

Risk of kidney failure in patients with systemic sclerosis: a nationwide population-based study

OBJECTIVE

Data from a decade ago have shown that patients with systemic sclerosis (SSc) have a higher risk of kidney failure than the general population. However, as the incidence of kidney failure due to SSc has been declining, the comparative risk of kidney failure between patients with SSc and the general population could have changed over time. We investigated the risk of kidney failure in patients with SSc compared with the general population, up to more recent years.

METHODS

This was a nationwide population-based study using the Korean National Health Insurance Service database. Patients with claims data for SSc between 2010 and 2017 (n=2591) and 1:5 age-matched and sex-matched controls (n=12 955) were selected. The index date was the earliest date of claim for SSc between 2010 and 2017. The follow-up duration was from the index date to 2019. The adjusted HRs (aHRs) and 95% CI for kidney failure were estimated using multivariable Cox proportional hazard models.

RESULTS

Over 5.2±2.6 years, the incidence rates of kidney failure in patients with SSc and controls were 2.88 and 0.35 per 1000 person-years, respectively. Patients with SSc had a significantly higher risk of kidney failure than controls (aHR=7.244, 95% CI=4.256 to 12.329). The effect size was larger in patients diagnosed with SSc between 2014 and 2017 (aHR=9.754, 95% CI=3.254 to 29.235) than in those diagnosed before 2010 (aHR=6.568, 95% CI=2.711 to 15.571) or between 2010 and 2013 (aHR=6.553, 95% CI=2.721 to 15.781).

CONCLUSION

The risk of kidney failure remains higher in patients with SSc than in the general population.

Research progress on mesenchymal stem cells and their exosomes in systemic sclerosis

Systemic sclerosis (SSc) is a connective tissue disease with an unknown etiology. Clinically, it is characterized by localized or diffuse skin thickening and fibrosis. The pathogenesis of SSc includes microvascular injury, autoimmune-mediated inflammation, and fibroblast activation. These processes interact and contribute to the diverse clinicopathology and presentation of SSc. Given the limited effectiveness and substantial side effects of traditional treatments, the treatment strategy for SSc has several disadvantages. Mesenchymal stem cells (MSCs) are expected to serve as effective treatment options owing to their significant immunomodulatory, antifibrotic, and pro-angiogenic effects. Exosomes, secreted by MSCs via paracrine signaling, mirror the effect of MSCs as well as offer the benefit of targeted delivery, minimal immunogenicity, robust reparability, good safety and stability, and easy storage and transport. This enables them to circumvent the limitations of the MSCs. When using exosomes, it is crucial to consider preparation methods, quality standards, and suitable drug delivery systems, among other technical issues. Therefore, this review aims to summarize the latest research progress on MSCs and exosomes in SSc, offering novel ideas for treating SSc.