Attribution of cause of end-stage renal disease among patients with systemic lupus erythematosus: the Georgia Lupus Registry

Diagnostic Utility of Galactose-Deficient Immunoglobulin A1 Immunostaining in the Differentiation of Lupus Nephritis and Immunoglobulin A Nephropathy

Background

Renal biopsy plays an important role in the establishment of the diagnosis and the management of patients with lupus nephritis. Immunoglobulin A (IgA) nephropathy rarely has been reported in kidney biopsy of lupus patients. Lupus nephritis and IgA nephropathy can be readily diagnosed on renal biopsy when the classic patterns are present. However, atypical patterns can become a diagnostic challenge. Galactose-deficient IgA1 (Gd-IgA1) is a key element in the pathogenesis of primary IgA nephropathy. Glomerular Gd-IgA1 deposits, detected by immunofluorescent staining of KM-55 (a Gd-IgA1-specific monoclonal antibody), are consistently identified in the mesangium of IgA nephropathy but are significantly less or absent in lupus nephritis accompanied by significant IgA deposition.

Case Presentation

Here we report the case of an 11-year-old girl who was recently diagnosed with systemic lupus erythematosus (SLE) and was found to have hematuria and proteinuria. Renal biopsy showed focal mesangial hypercellularity with IgA dominant, "full house" like pattern of mesangial deposition. The biopsy findings present a diagnostic dilemma with the differential diagnosis of IgA nephropathy versus lupus nephritis with atypical immunofluorescence, and IgA nephropathy is favored, in the absence of strong straining of C1q or C3, extraglomerular deposits, tissue antinuclear antibodies, and endothelial tubuloreticular inclusions. However, no detectable glomerular KM-55 staining was seen in the kidney biopsy.

Conclusions

We demonstrate the unique diagnostic utility of immunostaining for KM-55 in a challenging kidney biopsy of an SLE patient with features suggestive of IgA nephropathy. The absence of KM-55 staining excludes IgA nephropathy, supporting a diagnosis of lupus nephritis with atypical immunofluorescence in this patient with SLE.

Quality of Care for the Screening, Diagnosis, and Management of Lupus Nephritis Across Multiple Health Care Settings

OBJECTIVE

We examined quality measures for screening, diagnosis, and treatment of lupus nephritis (LN) among participants of the California Lupus Epidemiology Study across 25 different clinical sites to identify gaps in quality of care.

METHODS

Data from 250 participants with lupus were analyzed across 3 sources (medical records, physician examination, and patient interviews). Overall performance on 8 quality measures was calculated separately for participants with and without LN. We used generalized estimating equations in which the outcome was performance on measures, adjusting for participant demographics, lupus disease severity, and practice characteristics.

RESULTS

Of 148 patients without LN, 42% underwent screening laboratory tests for nephritis, 38% underwent lupus activity serum studies, and 81% had their blood pressure checked every 6 months. Of 102 LN patients, 67% had a timely kidney biopsy, at least 81% had appropriate treatment, and 78% achieved target blood pressure within 1 year of diagnosis. Overall performance in participants across quality measures was 54% (no LN) and 80% (LN). Significantly higher overall performance for screening measures for LN was seen at academic (63.4-73%) versus community clinics (37.9-38.4%). Similarly, among those with LN, higher performance in academic (84.1-85.2%) versus community clinics (54.8-60.2%) was observed for treatment measures.

CONCLUSION

In this quality-of-care analysis across 25 diverse clinical settings, we found relatively high performance on measures for management of LN. However, future work should focus on bridging the gaps in lupus quality of care for patients without nephritis, particularly in community settings.

A review of non-immune mediated kidney disease in systemic lupus erythematosus: A hypothetical model of putative risk factors

About half of patients with systemic lupus erythematosus (SLE) are diagnosed with lupus nephritis (LN). Patients with SLE are also at increased risk for diabetes, hypertension and obesity, which together account for >70% of end-stage renal disease in the general population. The frequencies of non-LN related causes of kidney disease, and their contribution to kidney disease development and progression among patients with SLE have been inadequately studied. We hypothesize that a substantial, and increasing proportion of kidney pathology in patients with SLE might not directly relate to LN but instead might be explained by non-immune mediated factors such as diabetes, hypertension, and obesity. The goal of the manuscript is to draw attention to hypertension, diabetes and obesity as potential alternative causes of kidney damage in patients with SLE. Further, we suggest that misclassification of kidney disease etiology in patients with SLE might have important ramifications for clinical trial recruitment, epidemiologic investigation, and clinical care. Future studies aiming to elucidate and distinguish discrete causes of kidney disease - both clinically and histologically - among patients with SLE are desperately needed as improved understanding of disease mechanisms is paramount to advancing therapeutic discovery. Collaboration among rheumatologists, pathologists, nephrologists, and endocrinologists, and the availability of dedicated research funding, will be critical to the success of such efforts.

Rapidly Progressive Glomerulonephritis Secondary to IgA Nephropathy in a Patient with Systemic Lupus Erythematosus

Lupus nephritis is a common manifestation of systemic lupus erythematosus (SLE). IgA nephropathy is a common type of primary glomerulonephritis. Renal manifestations in SLE patients are often due to lupus nephritis; however, renal diseases unrelated to lupus nephritis are rarely reported. While crescentic IgA nephropathy with rapid clinical progression is rare, its development in patients with SLE in the absence of lupus nephritis is even more unusual. A 74-year-old woman with a history of SLE without known renal involvement, chronic kidney disease stage IIIa, congestive heart failure, hypertension, and type 2 diabetes mellitus presented with acute kidney injury. Her creatinine continued to rise rapidly. Renal biopsy revealed mesangial proliferative glomerulonephritis with crescent formation. Immunofluorescent staining showed IgA and C3 mesangial deposition and absence of C4 and C1q, consistent with IgA nephropathy. She received a course of methylprednisolone and plasmapheresis. Unfortunately, her renal function continued to deteriorate, and she was started on hemodialysis which was continued after hospital discharge. This case illustrates crescentic IgA nephropathy without lupus nephritis as the cause of acute kidney injury in a patient with SLE. It highlights the observation that renal diseases other than lupus nephritis can develop in SLE patients.

Sex Differences in Health Care Utilization, End-Stage Renal Disease, and Mortality Among Medicaid Beneficiaries With Incident Lupus Nephritis

OBJECTIVE

While systemic lupus erythematosus and lupus nephritis (LN) disproportionately affect females, previous studies suggest that males may experience poorer outcomes. We undertook this study to investigate sex differences in health care utilization, end-stage renal disease (ESRD), and mortality among patients with LN receiving Medicaid, public insurance for low-income individuals.

METHODS

Within the Medicaid Analytic eXtract (MAX) from 29 states (from 2000 to 2010), we used billing claims to identify individuals ages 5-65 years with incident LN (positive predictive value 80%). MAX data were linked to the US Renal Data System to determine ESRD and to Social Security Death Index files to determine death. We estimated adjusted incidence rate ratios (IRRs) by sex for health care utilization using Poisson regression, and we used multivariable proportional hazards models to compare risks of ESRD and death by sex.

RESULTS

Of 2,750 patients with incident LN, 283 (10%) were male. The mean ± SD follow-up period for both sexes was 3.1 ± 2.3 years. The mean ± SD age was 29.6 ± 13.9 years among females and 24.7 ± 14.1 years among males (P < 0.01). Males had fewer outpatient visits (IRR 0.88 [95% confidence interval (95% CI) 0.80-0.97]) and fewer emergency department visits (IRR 0.75 [95% CI 0.63-0.90]). The 5-year cumulative incidence of ESRD was 22.3% in males and 21.2% in females. The 5-year cumulative incidence of death was 9.4% in males and 9.8% in females. Comparing males to females, there were no sex differences in ESRD (subdistribution hazard ratio [HR] 1.05 [95% CI 0.76-1.45]) or death (HR 0.81 [95% CI 0.47-1.35]).

CONCLUSION

In this cohort of patients with incident LN, ESRD and mortality were extremely high overall but were not increased among males compared to females. In this vulnerable population, biologic and health care utilization differences by sex may not significantly affect outcomes.

Validation of Systemic Lupus Erythematosus Diagnosis as the Primary Cause of Renal Failure in the US Renal Data System

OBJECTIVE

Using American College of Rheumatology (ACR) and Systemic Lupus International Collaborating Clinics (SLICC) criteria for systemic lupus erythematosus (SLE) classification as gold standards, we determined sensitivity, specificity, positive and negative predictive values (PPV and NPV) of having SLE denoted as the primary cause of end-stage renal disease (ESRD) in the US Renal Data System (USRDS).

METHODS

ESRD patients were identified by International Classification of Diseases, Ninth Revision codes in electronic medical records of 1 large tertiary care center, Montefiore Hospital, from 2006 to 2012. Clinical data were extracted and reviewed to establish SLE diagnosis. Data were linked by social security number, name, and date of birth to the USRDS, where primary causes of ESRD were ascertained.

RESULTS

Of 7,396 ESRD patients at Montefiore, 97 met ACR/SLICC SLE criteria, and 86 had SLE by record only. Among the 97 SLE patients, the attributed causes of ESRD in the USRDS were 77 SLE and 12 with other causes (unspecified glomerulonephritis, hypertension, scleroderma), and 8 missing. Sensitivity, specificity, PPV, and NPV for SLE in the USRDS were 79%, 99.9%, 93%, and 99.7%, respectively. Of the 60 patients with biopsy-proven lupus nephritis, 44 (73%) had SLE as primary ESRD cause in the USRDS. Attribution of the primary ESRD causes among SLE patients with ACR/SLICC criteria differed by race, ethnicity, and transplant status.

CONCLUSION

The diagnosis of SLE as the primary cause of ESRD in the USRDS has good sensitivity, and excellent specificity, PPV, and NPV. Nationwide access to medical records and biopsy reports may significantly improve sensitivity of SLE diagnosis.

iTRAQ-Based Proteomics of Chronic Renal Failure Rats after FuShengong Decoction Treatment Reveals Haptoglobin and Alpha-1-Antitrypsin as Potential Biomarkers

Background. Chronic renal failure (CRF) has become a global health problem and bears a huge economic burden. FuShengong Decoction (FSGD) as traditional Chinese medicine has multiple pharmacological effects. Objectives. To understand the underlying molecular mechanism and signaling pathway involved in the FSGD treatment of CRF and screen differentially expressed proteins in rats with CRF treated with FSGD. Methods. Thirty-three male Sprague-Dawley rats were randomly divided into control group, CRF group, and FSGD group. Differentially expressed proteins were screened by iTRAQ coupled with nanoLC-MS/MS, and these identified proteins were later analyzed by GO, KEGG, and STRING. Additionally, haptoglobin (HP) and alpha-1-antitrypsin (AAT) were finally verified by ELISA, Western blot, and real time PCR. Results. A total of 417 proteins were identified. Nineteen differentially expressed proteins were identified in the FSGD group compared with the model group, of which 3 proteins were upregulated and 16 proteins were downregulated. Cluster analysis indicated that inflammatory response was associated with these proteins and complement and coagulation cascade pathways were predominantly involved. The validation methods further confirmed that the levels of HP and AAT were significantly increased. Conclusions. HP and AAT may be the important biomarkers in the pathogenesis of CRF and FSGD therapy.

Comparison of vascular access outcomes in patients with end-stage renal disease attributed to systemic lupus erythematosus vs. other causes: a retrospective cohort study

BACKGROUND

U.S. hemodialysis patients with systemic lupus erythematosus (SLE) and end-stage renal disease (ESRD) are less likely than other ESRD patients to have a permanent vascular access (fistula or graft) in place at the dialysis start. We examined whether vascular access outcomes after dialysis start differed for SLE vs. other ESRD patients.

METHODS

Among U.S. patients initiating hemodialysis in 2010 with only a catheter (n = 40,911; 384 with SLE) and using a permanent access on first dialysis (n = 13,073; 48 with SLE), we examined the association of SLE status with time to first placement of a permanent access (among catheter-only patients) and to loss of access patency (among patients using a permanent access on first dialysis), both censored 1 year after dialysis start, using multivariable Cox proportional hazards models.

RESULTS

Among catheter-only patients, 46.1 % vs. 54.5 % of those with SLE-ESRD vs. other ESRD had a permanent access placed within 1 year after dialysis start. However, with adjustment, there was no association of 1-year placement with SLE status [HR = 1.00 (95 % CI, 0.86-1.17)]. SLE-ESRD vs. other ESRD patients starting dialysis with a permanent access were less likely to experience a 1-year loss of patency (43.8 % vs. 55.0 %), but this association was not statistically significant after adjustment [HR = 0.88 (0.57-1.37)].

CONCLUSION

These results suggest that SLE-ESRD patients starting dialysis with a catheter are not more likely to have a permanent access placed in the first year of dialysis, despite an observed lack of association of SLE status with subsequent loss of vascular access patency among those starting dialysis with a permanent access.