Kidney Involvement in Systemic Sclerosis

Bibliometric insights into systemic sclerosis with renal involvement: trends, contributions, and future directions

BACKGROUND

Renal involvement is not uncommon in patients with systemic sclerosis (SSc) and presents in various forms, particularly progressing to scleroderma renal crisis (SRC), which is associated with poor prognosis. Therefore, understanding the research trends in this field is critical for advancing clinical management and therapeutic strategies.

METHODS

A bibliometric analysis was conducted using the Web of Science Core Collection, examining publications related to SSc and renal involvement from January 2000 to November 2024. We analyzed publication trends, key contributors, institutions, and countries.

RESULTS

A total of 1,339 publications were identified in the field of SSc and renal involvement, demonstrating an upward trend in publication volume from 2000 to 2024. These articles have been cited a total of 61,234 times, with the majority of contributions coming from the United States, Italy, and East Asian countries. The University of Michigan and University College London were particularly prominent in terms of both publication volume and collaboration networks. Keyword analysis revealed a shift in research focus, with increasing attention on clinical aspects, pathophysiological mechanisms, and vascular complications.

CONCLUSIONS

This study provides a comprehensive overview of the research landscape on SSc with renal involvement, highlighting the key contributors and emerging trends.

Case of successful treatment with glucocorticoid for isolated anti-centromere antibody-positive acute interstitial nephritis

Acute interstitial nephritis (AIN) is known to cause acute kidney injury and is characterized by immunocyte infiltration and interstitial fibrosis. Primary etiologies include drugs, infections, and autoimmune disorders. Herein, we presented the case of a 78-year-old woman patient with AIN with anti-centromere antibody (ACA) positivity, secondary to an idiopathic immune system disorder. Her serum creatinine (sCr) was 0.67 mg/dL 2 months prior to consulting us, which increased to 2.79 mg/dL. The renal biopsy revealed an AIN comprising interstitial infiltration with immunocytes and CD138 + cells. Furthermore, all other antibodies tested negative using immunofluorescence on both glomeruli and tubulointerstitial lesions. The ACA was elevated to a level of ≥ 500 U/mL. The ACA positive has been known to be accompanied by worsening kidney function in patients with systemic sclerosis and primary biliary cholangitis. However, any autoimmune disease were not diagnosed. Successful treatment with an initial dose of 30 mg/day of glucocorticoids tapered to 25 mg/day resulted in a decrease in the sCr to 1.53 mg/dL 4 weeks later. Nine months later, glucocorticoids was tapered, based on the threshold of a sCr of 1.03 mg/dL and the titer of ACA of 291 U/mL. In this case, glucocorticoid treatment remarkably improved renal function in AIN containing CD138 + cells accompanied by a reduction of ACA titer. The etiology of ACA-positive AIN was unknown; however, the incidence of ACA-positive AIN should always be deliberated.

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.

Nintedanib in systemic sclerosis treatment: a case report

BACKGROUND

Nintedanib was approved for the treatment of scleroderma and scleroderma-related interstitial lung disease, as it decrease the forced expiratory volume.

CASE PRESENTATION

A 48-year-old Asian female patient with systemic scleroderma 6 years ago developed breathlessness, nausea, heart palpation, and sudden severe occipital headache over the preceding week. She was receiving aspirin 81 mg/day and amlodipine 5 mg/day. Her diagnosis was diffuse scleroderma with pulmonary hypertension, interstitial lung involvement, and renal crisis. The modified Rodnan score was 18. We begin captopril at a dose of 12.5 mg, progressively escalating to 200 mg/day, and oral nintedanib was started at 150 mg. A total of 12 months after initiation of treatment, the patient's kidney function was normal. The pulmonary function tests improved. The modified Rodnan score was reduced to 10. We did not encounter any side effects in our case due to nintedanib treatment.

CONCLUSION

Treatment with nintedanib is crucial for slowing lung function decline. Diarrhea was the most common adverse event. Scleroderma renal crisis occurs in 10% of patients and typically presents with an abrupt onset of hypertension and kidney failure. The optimal antihypertensive agent for scleroderma renal crisis is an ACE inhibitor. The mainstay of therapy in scleroderma renal crisis has been shown to improve or stabilize renal function in approximately 70% of patients and improve survival in nearly 80% at 1 year. Nintedanib may be effective, and fairly safe to use. Further exploration is anticipated to advance a new period of systemic sclerosis treatment.

Studying the Role of C5-Inhibition Therapy in Scleroderma Renal Crisis-Induced Thrombotic Microangiopathy - A Review of Literature

BACKGROUND

The pathogenesis of scleroderma renal crisis (SRC) remains poorly understood but a growing body of evidence suggests that activation of the complement system may be involved in the disease. Recent studies have shown that Eculizumab (monoclonal antibody directed against the complement component C5) is effective in treating patients with SRC who present with symptoms of thrombotic microangiopathy (SRC-TMA).

OBJECTIVES

In this study, we conducted a systematic review to characterize the published experience of the presentation and outcome of patients with SRC who were treated with C5 inhibitor, Eculizumab.

METHODS

A literature search was conducted from inception to December 2022 using Medical Subject Headings (MeSH) terms for 'scleroderma', 'scleroderma renal crisis, and 'Eculizumab'. We included case reports, case series, and observational studies which reported the use of Eculizumab with or without Angiotensin-converting enzyme inhibitors (ACE-I) for the treatment of scleroderma renal crisis (SRC) in patients with systemic sclerosis.

RESULTS

The study included 17 patients, all of whom were treated with Eculizumab. Additionally, the use of ACE-I was reported in 11/17 (64.7%) patients. Further, plasmapheresis was used in 9/17 (52.9%), steroids in 5/17 (29.4%), cyclophosphamide in 3/17 (17.6%), calcium channel blockers in 3/17 (17.6%), and Rituximab in 3/17 (17.6%) patients. Renal replacement therapy was required in 11/17 (64.7%) patients. 14/17 patients (82.3%) were reported to have clinical (renal or hematologic) improvement with Eculizumab therapy (Table 1).

CONCLUSION

These findings should prompt testing on a larger cohort of SRC-TMA patients. This would help us determine whether aggressive treatment combining ACE-I and Eculizumab can target the various underlying endothelial, inflammatory, and immunologic mechanisms involved in SRC-TMA, and improve patient outcomes.

National Trends in Mortality and Urgent Dialysis after Acute Hypertension in Japan From 2010 Through 2019

BACKGROUND

Despite increasing incidences of hypertension, recent trends in mortality and urgent dialysis following acute hypertension (AHT) remain undetermined.

METHODS

This retrospective observational cohort study evaluated 50 316 hospitalized AHT patients from 2010 to 2019, using an administrative claims database in Japan. We examined trends in incidence, urgent dialysis, mortality, and its risk factors using Poisson regression models. Using International Classification of Disease and Related Health Problems, 10th Revision codes, AHT was categorized into 5 spectrums: malignant hypertension (n=1792), hypertensive emergency (n=17 907), hypertensive urgency (n=1562), hypertensive encephalopathy (n=6593), and hypertensive heart failure (HHF; n=22 462).

RESULTS

The median age of the patients was 76 years, and 54.9% were women. The total AHT incidence was 70 cases per 100 000 admission year. The absolute death rate increased from 1.83% (95% CI, 1.40-2.40) to 2.88% ([95% CI, 2.42-3.41]; Cochran-Armitage trend test, P<0.0001). Upward trends were observed in patients aged ≥80, with lean body mass index ≤18.4, and with HHF. Urgent dialysis rates increased from 1.52% (95% CI, 1.12-2.06) to 2.60% (2.17-3.1; Cochran-Armitage trend test; P=0.0071) in 48 235 patients, excluding maintenance dialysis patients. Older age, men, lean body mass, malignant hypertension, HHF, and underlying chronic kidney disease correlated with higher mortality risk; greater hospital volume correlated with lower mortality risk; and malignant hypertension, HHF, diabetes, chronic kidney disease, and scleroderma correlated with a higher risk of urgent dialysis.

CONCLUSIONS

Mortality and urgent dialysis rates following AHT have increased. Aging, complex comorbidities, and HHF-type AHT contributed to the rising trend of mortality.

Biomarkers in Systemic Sclerosis: An Overview

Systemic sclerosis (SSc) is a complex autoimmune disease characterized by significant fibrosis of the skin and internal organs, with the main involvement of the lungs, kidneys, heart, esophagus, and intestines. SSc is also characterized by macro- and microvascular damage with reduced peripheral blood perfusion. Several studies have reported more than 240 pathways and numerous dysregulation proteins, giving insight into how the field of biomarkers in SSc is still extremely complex and evolving. Antinuclear antibodies (ANA) are present in more than 90% of SSc patients, and anti-centromere and anti-topoisomerase I antibodies are considered classic biomarkers with precise clinical features. Recent studies have reported that trans-forming growth factor β (TGF-β) plays a central role in the fibrotic process. In addition, interferon regulatory factor 5 (IRF5), interleukin receptor-associated kinase-1 (IRAK-1), connective tissue growth factor (CTGF), transducer and activator of transcription signal 4 (STAT4), pyrin-containing domain 1 (NLRP1), as well as genetic factors, including DRB1 alleles, are implicated in SSc damage. Several interleukins (e.g., IL-1, IL-6, IL-10, IL-17, IL-22, and IL-35) and chemokines (e.g., CCL 2, 5, 23, and CXC 9, 10, 16) are elevated in SSc. While adiponectin and maresin 1 are reduced in patients with SSc, biomarkers are important in research but will be increasingly so in the diagnosis and therapeutic approach to SSc. This review aims to present and highlight the various biomarker molecules, pathways, and receptors involved in the pathology of SSc.