Renal disorders in rheumatologic diseases: the spectrum is changing (Part 1: connective tissue diseases)

[Clinical characteristics and labial gland pathological features in children with systemic lupus erythematosus complicated by Sjögren's syndrome]

OBJECTIVES

To study the clinical manifestations, laboratory features, and labial gland pathological features in children with systemic lupus erythematosus (SLE) complicated by Sjögren's syndrome (SS).

METHODS

A retrospective analysis was conducted on 102 children with SLE who underwent labial gland biopsies at Renji Hospital, Shanghai Jiao Tong University School of Medicine from January 2013 to December 2022. The children were divided into two groups based on the presence of SS: the SLE with SS group (SLE-SS; 60 children) and the SLE-only group (42 children). According to the focus score (FS) of the labial glands, children in the SLE-SS group were further subdivided into FS≥4 subgroup (26 children) and FS<4 subgroup (34 children). The clinical data of the groups were compared.

RESULTS

Compared to the SLE-only group, children in the SLE-SS group had less skin and mucosal involvement, were more likely to have positive anti-SSA and anti-SSB antibodies, and had higher levels of rheumatoid factor (P<0.05). There was no significant difference in treatment protocols between the two groups (P>0.05). Compared to the FS<4 subgroup, the FS≥4 subgroup had more frequent musculoskeletal involvement (P<0.05), but there was no significant difference in SLE disease activity or other major organ involvement between the subgroups (P>0.05).

CONCLUSIONS

Children with SLE complicated by SS are less likely to have skin and mucous membrane involvement and exhibit specific serological characteristics. The SLE-SS children with an FS≥4 are more likely to experience musculoskeletal involvement. However, FS is not associated with disease activity or other significant organ damage.

Postoperative acute kidney injury after on-pump cardiac surgery in patients with connective tissue disease

Objective

Patients with connective tissue disease have a poor prognosis after receiving cardiac surgery. This study described the clinical scenarios and investigated factors correlated with acute kidney injury (AKI) after on-pump cardiac surgery in patients with systemic lupus erythematosus (SLE) or vasculitis.

Methods

Patients with SLE or vasculitis who underwent on-pump cardiac surgery from March 2002 to March 2022 were enrolled, while patients with preoperative renal dysfunction were excluded. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Uni- and multivariable analyses were performed to identify potential factors associated with postoperative AKI.

Results

Among 123 patients enrolled, 39 (31.7%) developed AKI within seven days after receiving on-pump cardiac surgery. Four patients died in the hospital, resulting in an overall in-hospital mortality of 3.3%, and all deaths occurred in the AKI group. Patients in the AKI group also had longer ICU stays (median difference 3.0 day, 95% CI: 1.0-4.0, P < 0.001) and extubation time (median difference 1.0 days, 95% CI: 0-2.0, P < 0.001) than those in the non-AKI group. Multivariable logistic regression revealed that BMI over 24 kg/m2 (OR: 3.00, 95% CI: 1.24-7.28) and comorbid SLE (OR: 4.73, 95% CI: 1.73-12.93) were independently correlated with postoperative AKI.

Conclusion

Factors potentially correlated with AKI following on-pump cardiac surgery in patients with connective tissue disease were explored. Clinicians should pay more attention to preoperative evaluation and intraoperative management in patients with risk factors.

Related factors of renal injury in primary Sjögren's syndrome

BACKGROUND

Primary Sjögren's syndrome (pSS) is a common chronic systemic autoimmune disorder which primarily affects the exocrine glands. Patients may have extraglandular disease involving multiple organs, including the kidneys. This study aimed at investigating the clinical data and laboratory markers which were associated with renal function damage or renal involvement.

METHOD

One thousand two hundred eighty-eight adult pSS patients from the Department of Rheumatology and Clinical Immunology were enrolled in this retrospective cohort study. And there were 334 patients of them followed up for more than two years for analyzing demographic, clinical data and laboratory markers. Statistical analysis was performed by R software (Version 3.6.2).

RESULT

Nearly 95% of 1288 pSS patients were women, and the positive rates of anti-SSA (Sjögren's syndrome A) and anti-SSB were 63% and 27% respectively. 12% of the pSS patients presented renal involvement with eGFR < 60 mL/min/1.73 m2, and the mean age of hospital presentation, serum creatinine and urea were the highest (P < 0.001), and ANA (antinuclear antibody)-positive, anti-SSB-positive and anti-scl-70-positive were more prevalent in this group. Multivariate analyses showed that age, urea, chlorine and anti-SSA indicate a significant association with renal dysfunction. Potassium, sodium and Jo-1 were also confirmed to be related with decreased renal function. The receiver operating characteristic (ROC) analysis including the above factors showed a good performance on the evaluation of renal injury including eGFR < 60 mL/min/1.73 m2 and eGFR 60 -90 mL/min/1.73 m2 in pSS, with area under curve (AUC) values of 0.957 and 0.821, and high sensitivity (71.1% and 84.4%) and specificity (95.5% and 70.5%). After a more than two years follow-up of anti-SSA positive patients, 34.14% of them developed decreased renal function, and 13.58% of them experienced a progression of renal injury with a 23.64% decrease in eGFR.

CONCLUSION

Age, urea, chlorine, and anti-SSA were highly associated with renal injury in pSS. Early screening for autoantibodies would be meaningful for evaluation and prevention of renal injury in pSS.

Renal tubular acidosis without interstitial nephritis in Sjögren's syndrome: a case report and review of the literature

BACKGROUND

Renal tubular acidosis is the principal clinical feature associated with tubulointerstitial nephritis in patients with primary Sjögren's syndrome. Renal tubular dysfunction due to interstitial nephritis has been considered the underlying pathophysiology connecting renal tubular acidosis and primary Sjögren's syndrome. However, the detailed mechanisms underlying the pathophysiology of renal tubular acidosis in primary Sjögren's syndrome is not fully understood.

CASE PRESENTATION

A 30-year-old woman was admitted with complaints of weakness in the extremities. The patient was hospitalized thirteen years earlier for similar issues and was diagnosed with hypokalemic paralysis due to distal renal tubular acidosis with primary Sjögren's syndrome. This diagnosis was based on a positive Schirmer's test. Besides, anti-Sjögren's syndrome-related antigen A was also detected. Laboratory tests indicated distal RTA; however, a renal biopsy showed no obvious interstitial nephritis. Laboratory tests conducted during the second admission indicated distal renal tubular acidosis. Therefore, a renal biopsy was performed again, which revealed interstitial nephritis. Histological analysis of acid-base transporters revealed the absence of vacuolar type H+-ATPases in the collecting duct. The vacuolar type H+-ATPase was also absent in the past renal biopsy, suggesting that the alteration in acid-base transporters is independent of interstitial nephritis.

CONCLUSIONS

This case study demonstrates that vacuolar-type H+-ATPases are associated with distal renal tubular acidosis, and distal renal tubular acidosis precedes interstitial nephritis in patients with primary Sjögren's syndrome.

Thrombotic Microangiopathy and Multiple Organ Failure in Scleroderma Renal Crisis: A Case Report

This case report can be considered a rare occurrence of scleroderma renal crisis (SRC) presenting with a severe clinical course and multiple organ failure. A patient diagnosed with systemic sclerosis four years earlier was admitted to the hospital because of severe malignant systolic-diastolic arterial hypertension and acute kidney injury (AKI). Exacerbating disease suggested thrombotic microangiopathy (TMA) and the PLASMIC (Platelet count; combined hemoLysis variable; absence of Active cancer; absence of Stem-cell or solid-organ transplant; MCV; INR; Creatinine) score was used in the differential diagnosis. Despite the timely initiation of therapy with ACE inhibitors (ACE-I), the progressive renal failure required hemodialysis treatment, but renal function never recovered. Disease duration, skin involvement, and previous specific pharmacological therapy represented multiple risk factors that determined a clinical course complicated by pericardial tamponade with acute heart failure, acute pancreatitis, and ischemic stroke, with fatal evolution. These complications presented a challenging clinical sequence of events requiring an interdisciplinary course of action. Timely ascertainment of the SRC is important given the possible severe organ involvement as well as mortality. A diagnosis of scleroderma renal crisis should be considered in cases of acute kidney injury associated with known risk factors. Early treatment and collaboration between rheumatology and renal physicians can improve patient outcomes.

Recommendations for evaluation and diagnosis of extra-glandular manifestations of primary sjogren syndrome: results of an epidemiologic systematic review/meta-analysis and a consensus guideline from the Brazilian Society of Rheumatology (articular, pulmonary and renal)

Sjogren's Syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration of the exocrine glands and other organs, associated with sicca syndrome but also with systemic involvement with varying degrees of severity. Despite their importance, these systemic manifestations are not routinely evaluated and there is no homogenous approach to their diagnosis or evaluation. To close this gap, a panel of experts from the Brazilian Society of Rheumatology conducted a systematic review and meta-analysis on the identification of epidemiologic and clinical features of these manifestations and made recommendations based on the findings. Agreement between the experts was achieved using the Delphi method. The first part of this guideline summarizes the most important topics, and 11 recommendations are provided for the articular, pulmonary, and renal care of SS patients.