Monitoring anti-PLA2R antibody titres to predict the likelihood of spontaneous remission of membranous nephropathy

Background

In anti-phospholipase A2 receptor (PLA2R) membranous nephropathy (MN) there is controversy whether spontaneous remission (SR) can be predicted using a single titre or by assessing the dynamic changes in anti-PLA2R antibody (ab) titres. The study objective was to identify the optimal dynamics of anti-PLA2Rab titres to predict SR in MN.

Methods

A total of 127 nephrotic patients with anti-PLA2R-MN were prospectively followed up for 6 months under conservative treatment. Anti-PLA2Rabs and proteinuria were assessed at diagnosis and monthly thereafter. The primary endpoint (PEP) was a reduction of proteinuria ≥50% at 6 months. Logistic models with baseline and evolutive anti-PLA2Rab titres were developed to predict the PEP.

Results

A total of 28 patients (22%) reached the PEP. These patients were more frequently female and had significantly lower baseline proteinuria and anti-PLA2Rab titres. An anti-PLA2R titre ≤97.5 RU/mL at diagnosis had a sensitivity of 71% and a specificity of 81% to predict the PEP. The model including baseline anti-PLA2Rabs and a reduction ≥15% at 3 months predicted the PEP with a sensitivity of 93% and a specificity of 80%, with an area under the curve that was significantly greater than that obtained with relative changes of proteinuria in the same period of time {odds ratio [OR] 0.95 [95% confidence interval (CI) 0.91–0.98 versus OR 0.79 [95% CI 0.70–0.88], respectively; P = 0.0013}.

Conclusions

Combining the baseline anti-PLA2Rab titres with their relative changes at 3 months after diagnosis gives the earliest prediction for achieving a reduction of urinary protein excretion ≥50% at 6 months in MN, thereby shortening the observation period currently recommended to make individualized decisions to start immunosuppressive therapy.

Association between urinary biomarkers and disease progression in adults with autosomal dominant polycystic kidney disease

Background

Height-adjusted total kidney volume (htTKV) is considered as the best predictor of kidney function in patients with autosomal dominant polycystic kidney disease (ADPKD), but its limited predictive capacity stresses the need to find new biomarkers of ADPKD progression. The aim of this study was to investigate urinary biomarkers of ADPKD progression.

Methods

This observational study included ADPKD patients, and two comparator groups of ischaemic and non-ischaemic kidney injury: benign nephroangiosclerosis patients and non-ischaemic chronic kidney disease (CKD) patients. Proteinuria, htTKV and urinary levels of molecules are associated with ischaemia and/or tubular injury. The slope of estimated glomerular filtration rate (eGFR) was used as a dependent variable in univariate and multivariate models of kidney function decline.

Results

The study included 130 patients with ADPKD, 55 with nephroangiosclerosis and 40 with non-ischaemic CKD. All patients had increased urinary concentrations of biomarkers associated with tubular lesions (liver fatty acid-binding protein, kidney injury molecule-1, β2-microglobulin) and molecules overexpressed under ischaemic conditions [hypoxia-inducible factor-1α, vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1)]. These biomarkers correlated positively with htTKV and negatively with the eGFR slope. htTKV was the single best predictor of the eGFR slope variability in univariate analyses. However, a multivariate model including urinary levels of β2-microglobulin, MCP-1 and VEGF improved the capacity to predict the decline of eGFR in ADPKD patients compared with htTKV alone.

Conclusions

The urinary levels of molecules associated with either renal ischaemia (VEGF and MCP-1) or tubular damage (β2-microglobulin) are associated with renal function deterioration in ADPKD patients, and are, therefore, candidates as biomarkers of ADPKD progression.

Long-term effectiveness of cinacalcet in non-dialysis patients with chronic kidney disease and secondary hyperparathyroidism

Background

Secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease (CKD). Cinacalcet use is controversial in non-dialysis patients.

Methods

This retrospective observational study recruited patients receiving cinacalcet (off-label use) in 2010 and 2011. Patients were followed for three years from the beginning of treatment using an intention-to-treat approach.

Results

Forty-one patients were studied: 14 CKD stage 3 (34.1%), 21 CKD stage 4 (51.2%), and 6 CKD stage 5 (14.6%). Median baseline parathyroid hormone (PTH) was 396 (101–1,300) pg/mL. Upon cinacalcet treatment (22 ± 12 months), PTH levels decreased by ≥ 30% in 73.2% of patients (P < 0.001; 95% confidence interval [CI], 59–87%), with a mean time for response of 18.7 months (95% CI, 15.4–22.1). Sixteen patients were followed for 36 months and treated for 32 ± 9 months. Mean reduction in their PTH levels was 50.1% (P < 0.001; 95% CI, 33.8–66.4%) at 36 months, with 62.5% of patients (P < 0.001; 95% CI, 35.9–89.1%) presenting reductions of ≥ 30%. Serum calcium levels decreased from 9.95 ± 0.62 mg/dL to 9.21 ± 0.83 and 9.12 ± 0.78 mg/dL at 12 and 36 months, respectively (P < 0.001). Serum phosphorus levels increased from 3.59 ± 0.43 to 3.82 ± 0.84 at 12 months (P = 0.180), remaining so at 36 months (P = 0.324). At 12 and 36 months, 2 (12.5%) patients experienced hypocalcemia. Meanwhile, 1 (6.3%) and 4 (25.0%) patients reported hyperphosphatemia at 12 and 36 months, respectively.

Conclusion

Cinacalcet remained effective for at least 36 months in non-dialysis patients with SHPT. Electrolytic disturbances were managed with concurrent use of vitamin D and its analogs or phosphate binders.

Prevalence and Risk Factors for Major Infections in Patients with Antineutrophil Cytoplasmic Antibody-associated Vasculitis: Influence on the Disease Outcome

OBJECTIVE

To analyze the role that infections play on the antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) outcome.

METHODS

A retrospective study of adult patients with AAV diagnosed in a tertiary center. Clinical features, laboratory findings, treatment, relapses, major infections, and outcome were evaluated.

RESULTS

Included were 132 patients [51 microscopic polyangiitis (MPA), 52 granulomatosis with polyangiitis (GPA), 29 eosinophilic GPA (EGPA)] with a mean followup of 140 (96-228) months. ANCA were positive in 85% of cases. A total of 300 major infections, mainly bacterial (85%), occurred in 60% patients during the followup. Lower respiratory tract (64%) and urinary tract infections (11%) were the most frequent, followed by bacteremia (10%). A total of 7.3% opportunistic infections were observed, most due to systemic mycosis. Up to 46% of all opportunistic infections took place in the first year of diagnosis, and 55% of them under cyclophosphamide (CYC) treatment. Bacterial infections were associated with Birmingham Vasculitis Activity Score (version 3) > 15 at the disease onset, a total cumulative CYC dose > 8.65 g, dialysis, and development of leukopenia during the followup. Leukopenia was the only factor independently related to opportunistic infections. Forty-four patients died, half from infection. Patients who had major infections had an increased mortality from any cause.

CONCLUSION

Our results confirm that major infections are the main cause of death in patients with AAV.

The European Renal Association - European Dialysis and Transplant Association (ERA-EDTA) Registry Annual Report 2016: a summary

Background

This article summarizes the ERA-EDTA Registry’s 2016 Annual Report, by describing the epidemiology of renal replacement therapy (RRT) for end-stage renal disease (ESRD) in 2016 within 36 countries.

Methods

In 2017 and 2018, the ERA-EDTA Registry received data on patients undergoing RRT for ESRD in 2016 from 52 national or regional renal registries. In all, 32 registries provided individual patient data and 20 provided aggregated data. The incidence and prevalence of RRT and the survival probabilities of these patients were determined.

Results

In 2016, the incidence of RRT for ESRD was 121 per million population (pmp), ranging from 29 pmp in Ukraine to 251 pmp in Greece. Almost two-thirds of patients were men, over half were aged ≥65 years and almost a quarter had diabetes mellitus as their primary renal diagnosis. Treatment modality at the start of RRT was haemodialysis for 84% of patients. On 31 December 2016, the prevalence of RRT was 823 pmp, ranging from 188 pmp in Ukraine to 1906 pmp in Portugal. In 2016, the transplant rate was 32 pmp, varying from 3 pmp in Ukraine to 94 pmp in the Spanish region of Catalonia. For patients commencing RRT during 2007–11, the 5-year unadjusted patient survival probability on all RRT modalities combined was 50.5%. For 2016, the incidence and prevalence of RRT were higher among men (187  and 1381 pmp) than women (101 and 827 pmp), and men had a higher rate of kidney transplantation (59 pmp) compared with women (33 pmp). For patients starting dialysis and for patients receiving a kidney transplant during 2007–11, the adjusted patient survival probabilities appeared to be higher for women than for men.

Value of urinary levels of interleukin-6, epidermal growth factor, monocyte chemoattractant protein type1 and transforming growth factor β1 in predicting the extent of fibrosis lesions in kidney biopsies of patients with IgA nephropathy

OBJECTIVE

To analyse the associations between urinary levels of IL-6 EGF, MCP-1 and TGFβ1 and clinical, biochemical and histopathological characteristics in patients with primary IgA nephropathy and their ability to predict the extent of lesions of glomerular and/or interstitial sclerosis.

PATIENTS AND METHODS

A total of 58 patients with IgA nephropathy were studied. We determined the urine levels of IL-6, EGF, MCP-1, and TGFβ1 at the time of diagnosis. The extent of glomerular and interstitial fibrosis was analyzed by quantitative morphometry and kidney biopsies were classified according to the Oxford criteria. We analysed the ability of these molecules to predict the extent of glomerular and interstitial fibrosis lesions.

RESULTS

IL-6, TGFβ1 and MCP-1 were associated with focal glomerulosclerosis and interstitial fibrosis extension but not with the presence of mesangial, extracapillary or endocapillary proliferation. EGF showed a negative association with interstitial fibrosis. By categorising patients according to the Oxford classification, patients with T1 and T2 scores had significantly higher levels of IL-6, MCP-1, TGF-β1 and significantly lower levels of EGF than patients with T0 scores. By multiple regression and logistic regression analyses, the levels of MCP-1, IL-6 and EGF were independent predictors of the fibrosis surface, after adjusting for age and eGFR.

CONCLUSION

The urinary concentration of IL-6, EGF and MCP-1 provides additional information that significantly improves the estimation of the surface of interstitial fibrosis in patients with IgA nephropathy.

Study of the variables associated with local complement activation in IgA nephropathy

OBJECTIVES

1. To identify the variables that are associated with urinary levels of properdin, MBL, C4d, and C5b-9 in patients with idiopathic IgA nephropathy. 2. To analyse whether urinary levels of MBL and/or C4d are useful for identifying the presence of mesangial deposits of C4d/MBL.

PATIENTS AND METHOD

A total of 96 patients with IgA nephropathy were studied. Demographic, clinical and biochemical variables were recorded at the time of diagnosis. Renal lesions were quantified using the Oxford classification. Immunohistochemical staining for MBL, MASP-2, properdin, C4d, and C5b-9 was performed in kidney biopsies, and in urine, the levels of properdin, MBL, C4d and C5b-9 were determined.

RESULTS

In multivariate analysis, the independent predictors of C4d and MBL levels in urine were the mesangial deposits of each protein and, to a lesser extent, the urinary protein excretion. The independent predictors of urinary levels of C5b-9 were MBL properdin and proteinuria. Urinary excretion of C4d had a sensitivity of 90% (95% CI: 58,7 to 99) and a specificity of 73% (95% CI: 54-87) for detecting mesangial C4d deposits, and the level of MBL had a sensitivity of 83.9% (95% CI: 62-95) and a specificity of 81.6% (95% CI: 65-92) for identifying mesangial deposits of MBL.

CONCLUSION

The main predictor of urinary concentration of C4d and MBL was the presence of their respective mesangial deposits. Urine MBL may contribute to complement activation in the tubular luz through the lectin pathway. Urinary levels of MBL and C4d could be sensitive and specific biomarkers for the identification of patients with mesangial deposits of MBL and C4d.

Effectiveness of Cinacalcet in Patients with Chronic Kidney Disease and Secondary Hyperparathyroidism Not Receiving Dialysis

Background

Secondary hyperparathyroidism (SHPT) is a common complication in chronic kidney disease (CKD) patients. Cinacalcet could be a therapeutic option although its use is controversial in patients not receiving dialysis. Thus, the aim of this study is to assess the effectiveness and safety of cinacalcet in patients with CKD and SHPT without renal replacement treatment (RRT) and without renal transplantation (RT).

Methods

A retrospective observational study was conducted. Patients were included if they had collected cinacalcet, under off-label use, during 2010 and 2011. Patients selected were followed from the beginning of cinacalcet therapy for one year of treatment.

Results

A total of 37 patients were included with CKD stage 3 (38%), 4 (51%) and 5 (11%). Baseline mean PTH value was 400.86 ± 168.60 mg/dl. At 12 months, a 67% of patients achieved at least a 30% reduction in their PTH value (p<0.001; CI 49.7–83.6), and the overall mean reduction of PTH values was 38% (p< 0.001; IC -49.1, -27.5). A 28% of the patients achieved KDOQI PTH goals (p = 0.003, CI 12%-50%). At 12 months, mean serum calcium values decreased by 6% and mean serum phosphorus values increased by 13%. A 19% of patients experienced hypocalcemia episodes while an increase of 24% in hyperphosphatemia episodes was observed. A 25% of patients finished cinacalcet before a year of treatment. Main withdrawal reasons were: gastrointestinal and other discomfort (8%), hypocalcaemia (8%), non-compliance (3%), interactions (3%) and excess of efficacy (3%).

Conclusions

Cinacalcet was effective in patients with CKD and SHPT not receiving dialysis. Electrolytic imbalances could be managed with administration of vitamin D and analogues or phosphate binders.

[Clinical features and prognosis of patients with scleroderma renal crisis]

BACKGROUND AND OBJECTIVE

Scleroderma renal crisis is a severe complication of systemic sclerosis, which causes arterial hypertension and acute renal failure. Early treatment of these patients with ACE inhibitors may improve prognosis. We aimed to analyze the frequency, clinical and epidemiological characteristics, morbidity and mortality and prognosis of scleroderma renal crisis.

PATIENTS AND METHODS

Retrospective study of a cohort of 328 patients with SSc, of whom 194 had the limited form, 64 the diffuse form, 49 the sine scleroderma and 21 preescleroderma. We considered different subtypes of disease: limited (188), diffuse (63), scleroderma sine scleroderma (46) and preescleroderma (21). The data were obtained from a review of medical records. The differences in the prevalence of variables were analyzed by the Fisher's test.

RESULTS

A renal crisis was observed in 14 patients (4.26%), 3 men and 11 women, 64% had the diffuse form of the disease, 28% had the limited form, and 7.69% had the scleroderma sine scleroderma. The average time was 48 months. All received ACE inhibitors. The mortality was 85% (18 months) and 85% required dialysis.

CONCLUSIONS

Renal crisis is a rare manifestation of scleroderma which mainly affects patients with diffuse involvement of the disease in the early stages. These patients have a poor prognosis despite treatment with ACE inhibitors.

Activation of the signal transducer and activator of transcription-1 in diffuse proliferative lupus nephritis

Difuse proliferative lupus nephritis (DPLN) is the most common and severe form of lupus nephritis. A predominance of IFN-gamma-producing T cells in both peripheral and renal tissues of patients with DPLN has been identified which suggests an important role for cell-mediated immunity in the pathogenesis of this complication in SLE. The biological effects of IFN-gamma rely mainly on the activity of the transcription factor called signal transducer and activator of transcription (STAT)-1. To assess the IFN-gamma/STAT-1 pathway in DPLN, we examined the expression of STAT-1 in renal biopsies from 15 DPLN patients by immunohistochemical staining with an anti-STAT-1 antibody. The expression of STAT-1 in renal tissues was correlated with several clinical and laboratory findings in these DNPN patients.STAT-1 was activated in the tubular cells in all DPLN patients. Seven of 15 DPLN biopsies (46.7%) showed positive cells in glomeruli. Five of these seven DPLN biopsies (71.4%) with positive glomerular cells showed a serum creatinine >1.5 mg/mL at the time the biopsy was carried out whereas only one of eight DPLN biopsy specimens (12.5%) without positive glomerular cells, showed a serum creatinine >1.5 mg/mL (P = 0.041). Moreover, the percentage of DPLN patients with a worse renal outcome in those who showed expression of STAT-1 in glomerulari were higher in comparison to those without STAT-1 expression (P = 0.041). Our results show that STAT-1 is activated in DPLN suggesting that biological effects of IFN-gamma in renal tissues depend, at least in part, on the activation of STAT-1.