Raised serum creatinine at presentation does not adversely affect steroid response in primary focal segmental glomerulosclerosis in adults

Clinical course and outcome of adult patients with primary focal segmental glomerulosclerosis with kidney function loss on presentation

BACKGROUND

Kidney function loss or renal insufficiency indicated by elevated creatinine levels and/or an estimated glomerular filtration rate (eGFR) < 60 mL/minute/1.73 m² at presentation in patients with primary focal segmental glomerulosclerosis (FSGS) is commonly seen as a poor prognostic marker for kidney survival. However, a pre>vious study from our center suggested this may be due to hemodynamic factors.

AIM

To observe the clinical and biochemical parameters, treatment response, kidney survival, and overall outcomes of adult patients with primary FSGS presenting with kidney function insufficiency.

METHODS

This retrospective observational study was conducted at the Department of Nephrology, Sindh Institute of Urology and Transplantation, Karachi, Pakistan, from January 1995 to December 2017. During this period, 401 biopsy-proven primary FSGS patients were identified, of which 98 (24.4%) presented with kidney function loss or renal insufficiency defined as eGFR < 60 mL/minute/1.73 m² at presentation and were studied in detail.

RESULTS

Among the 98 patients with renal function loss on presentation, the mean age was 30.9 years ± 13.6 years with a male-to-female ratio of 2.5:1. The mean serum creatinine level was 2.2 mg/dL ± 1.3 mg/dL and mean eGFR 37.1 mL/minute/1.73 m² ± 12.8 mL/minute/1.73 m². The mean 24-hour urinary protein excretion was 5.9 g/day ± 4.0 g/day, and the mean serum albumin was 2.1 g/dL ± 1.0 g/dL (median: 1.5 g/dL). The mean systolic blood pressure (BP) was 132.7 mmHg ± 19.8 mmHg, and the mean diastolic BP was 87.4 mmHg ± 12.7 mmHg. Steroid treatment was given to 81 (82.6%) of 98 patients for an average duration of 19.9 weeks ± 14.4 weeks, with a mean total steroid dose of 4.4 g ± 1.5 g. Treatment response showed that 20 (24.6%) patients achieved complete remission, 9 (11.1%) achieved partial remission, and 52 (64.1%) did not respond. The baseline eGFR was significantly lower in the non-responsive group (P = 0.006). The distribution of FSGS variants was also significantly different among steroid-responsive and non-responsive groups (P = 0.012).

CONCLUSION

Renal function loss in FSGS patients at presentation does not necessarily indicate irreversible kidney function loss and a significant number of patients respond to appropriate treatment of the underlying disease.

Clinicopathological features and medium-term outcomes of histologic variants of primary focal segmental glomerulosclerosis in adults: A retrospective study

BACKGROUND

The Columbia classification identified five histological variants of focal segmental glomerulosclerosis (FSGS). The prognostic significance of these variants remains controversial.

AIM

To evaluate the relative frequency, clinicopathologic characteristics, and medium-term outcomes of FSGS variants at a single center in Pakistan.

METHODS

This retrospective study was conducted at the Department of Nephrology, Sindh Institute of Urology and Transplantation, Karachi, Pakistan on all consecutive adults (≥ 16 years) with biopsy-proven primary FSGS from January 1995 to December 2017. Studied subjects were treated with steroids as a first-line therapy. The response rates, doubling of serum creatinine, and kidney failure (KF) with replacement therapy were compared between histological variants using ANOVA or Kruskal Wallis, and Chi-square tests as appropriate. Data were analyzed by SPSS version 22.0. P-value ≤ 0.05 was considered significant.

RESULTS

A total of 401 patients were diagnosed with primary FSGS during the study period. Among these, 352 (87.7%) had a designated histological variant. The not otherwise specified (NOS) variant was the commonest, being found in 185 (53.9%) patients, followed by the tip variant in 100 (29.1%) patients. Collapsing (COL), cellular (CEL), and perihilar (PHI) variants were seen in 58 (16.9%), 6 (1.5%), and 3 (0.7%) patients, respectively. CEL and PHI variants were excluded from further analysis due to small patient numbers. The mean follow-up period was 36.5 ± 29.2 months. Regarding response rates of variants, patients with TIP lesions achieved remission more frequently (59.5%) than patients with NOS (41.8%) and COL (24.52%) variants (P < 0.001). The hazard ratio of complete response among patients with the COL variant was 0.163 [95% confidence interval (CI): 0.039-0.67] as compared to patients with NOS. The TIP variant showed a hazard ratio of 2.5 (95%CI: 1.61-3.89) for complete remission compared to the NOS variant. Overall, progressive KF was observed more frequently in patients with the COL variant, 43.4% (P < 0.001). Among these, 24.53% of patients required kidney replacement therapy (P < 0.001). The hazard ratio of doubling of serum creatinine among patients with the COL variant was 14.57 (95%CI: 1.87-113.49) as compared to patients with the TIP variant.

CONCLUSION

In conclusion, histological variants of FSGS are predictive of response to treatment with immunosuppressants and progressive KF in adults in our setup.

Glomerular parietal epithelial expression of CD44 in minimal change nephrotic syndrome and primary focal segmental glomerulosclerosis: A clinico-pathological study

Introduction

Minimal change nephrotic syndrome (MCNS) and focal segmental glomerulosclerosis (FSGS) are the two common causes of nephrotic syndrome (NS) in both children and adults with overlapping clinical features, but with distinct prognostic and therapeutic implications. The distinction between these relies entirely on histopathology, which can sometimes be difficult. CD44 is expressed by activated parietal epithelial cells, plays a role in matrix deposition and thus in the pathogenesis of FSGS.

Aims

To assess the expression of CD44 in MCNS and FSGS and to evaluate its association with the known clinical and histopathological prognostic factors.

Materials and Methods

Thirty cases each of MCNS and FSGS were studied. The clinical, laboratory, histopathological, and CD 44 immunohistochemical data were recorded. The findings were analyzed and correlated. A P value of < 0.05 was considered statistically significant.

Results

Statistical association was noted between CD44 positivity and serum creatinine (p = 0.031), estimated glomerular filtration rate (p = 0.040), segmental sclerosis (p < 0.001), tubular atrophy (p = 0.027), interstitial fibrosis (p = 0.027), and histological diagnosis (p < 0.001). The sensitivity, specificity, positive predictive, and negative predictive values were 90%, 76.67%, 79.41% and 88.46%, respectively.

Conclusions

CD44 immunostain can effectively distinguish MCNS from FSGS. The congruent results of CD44 positivity with known prognostic factors support the possibility of using the CD44 marker as a predictive tool in selecting high-risk patients and offering appropriate therapeutic measures.

Efficacy and Safety of Immunosuppressive Therapy in Primary Focal Segmental Glomerulosclerosis: A Systematic Review and Meta-analysis

Rationale & Objective

Focal segmental glomerulosclerosis (FSGS) is a rare condition that can lead to kidney function decline and chronic kidney failure. Immunosuppressants are used to treat primary FSGS. However, their efficacy and safety in FSGS are not clearly established. We assessed current knowledge on clinical effectiveness and safety of immunosuppressants for primary FSGS.

Study Design

Systematic review of randomized controlled trials, interventional nonrandomized controlled trials, observational studies, retrospective studies, and registries.

Setting & Participants

Patients with primary and genetic FSGS.

Selection Criteria for Studies

Medline, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for English-language, primary-FSGS studies from inception to 2019. Clinical outcomes were changes from baseline in proteinuria, kidney function, and kidney survival.

Data Extraction

2 investigators independently screened studies and extracted data.

Analytical Approach

Study results were summarized using random-effects models either as ratios of means between follow-up and baseline measurements or as HRs.

Results

We included 98 articles. Substantial heterogeneity was observed in patient baseline characteristics and study designs. Most studies assessed treatment with corticosteroids alone or combined with other drugs, mainly immunosuppressants. Patients treated with immunosuppressants showed reduced proteinuria (14 studies; ratio of means, 0.36; 95% CI, 0.20-0.47), decreased creatinine clearance (mean difference, −25.03; 95% CI, −59.33 to −9.27) and (significantly) lower estimated glomerular filtration rates (mean difference, −7.61 mL/min/1.73 m²; 95% CI, −14.98 to 0.25 mL/min/1.73 m²). Immunosuppressant therapy had an uncertain effect on reducing the chronic kidney failure risk. Hypertension and infections were the most commonly reported adverse events.

Limitations

Heterogeneity in study designs, patient populations, and treatment regimens; no access to individual patient–level data.

Conclusions

This systematic review supports proteinuria reduction with immunosuppressant therapy in primary FSGS over varying follow-up periods. The effects of immunosuppressants on kidney survival remain uncertain. This review underscores the need for better-designed and adequately controlled studies to assess immunosuppressant therapy in patients with primary FSGS.

Glucocorticoids in the treatment of patients with primary focal segmental glomerulosclerosis and moderate proteinuria

BACKGROUND

To compare the efficacy of glucocorticoids in primary focal segmental glomerulosclerosis (pFSGS) patients with moderate proteinuria. Registered at http://www.chictr.org.cn/ , study No. ChiCTR-OPN-17012789.

METHODS

pFSGS patients with urine protein between 1.0 and 3.5 g/24 h were recruited from 2006 to 2016. No decline in urine protein > 50% was observed after 2 months of run-in angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers (ACEI/ARB) treatment. Patients were assigned to study group (glucocorticoids with ACEI/ARB) or control group (ACEI/ARB without glucocorticoids). Variables including 24-h urinary protein, serum albumin and serum creatinine during the trial were recorded. Remission was defined as proteinuria < 0.3 g/24 h or declined > 50%, and our composite end point as > 30% decrease of eGFR or eGFR < 30 ml/min.

RESULTS

A total of 102 patients were enrolled (study group N = 52, control group N = 50), and the median follow-up time was 36 (12-117) months without significant difference between groups. During the 12-month follow-up, the remission rate was significantly higher in study group [73.1 vs 50.0% (P = 0.01)], and the initial median response time was 3 months in the study group while 6 in the control group. The end point was reached by 22.2% cases in study group, and 42.0% in control. The medium survival times were study group 72 months and control 57 (P = 0.03). Minor adverse reactions were observed in 10 patients (study group N = 8, control group N = 2).

CONCLUSIONS

Additional glucocorticoids therapy is more efficacious compared to ACEI/ARB alone in the treatment of patients with pFSGS and moderate proteinuria.

Clinical presentation, treatment and outcome of focal segmental glomerulosclerosis in Far North Queensland Australian adults

AIM

The aim is to describe the clinical features, treatment and outcomes in Australian adults with focal segmental glomerulosclerosis and identify predictors of disease progression and all-cause mortality.

METHODS

The study included all patients with biopsy confirmed focal segmental glomerulosclerosis between January 1997 and June 2014 at participating hospitals. Clinical factors, histopathological findings, biochemical markers and treatments were analysed and potential predictors of doubling serum creatinine, end stage kidney disease or death identified.

RESULTS

A total of 98 patients were included with a median follow up of 4.3 years. Thirty-four (35%) patients were Aboriginal or Torres Strait Islander. Focal segmental glomerulosclerosis not-otherwise-specified was the most common variant. Seventeen (59%) patients initially treated with immunosuppression experienced an improvement in renal function. At the end of follow up, 43 (44%) patients had progressed to the composite outcome. Baseline tubulointerstitial scarring and lower haemoglobin predicted shorter time to doubling serum creatinine. Dual diagnosis, higher serum creatinine, lower estimated glomerular filtration rate and doubling creatinine were associated with shorter time to end stage kidney disease with remission the only protective factor. Age was the only variable associated with all-cause mortality.

CONCLUSION

Focal segmental glomerulosclerosis holds serious implications for patients. Concomitant diabetic nephropathy, higher serum creatinine and lower estimated glomerular filtration rate at renal biopsy were associated with poorer renal prognosis. Indigenous people had a female predominance and are over-represented in relation to their population size, however, were not associated with poorer prognosis. Remission was the only modifiable variable and thus should be at the forefront of patient management goals and future studies.

Focal Segmental Glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a leading cause of kidney disease worldwide. The presumed etiology of primary FSGS is a plasma factor with responsiveness to immunosuppressive therapy and a risk of recurrence after kidney transplant-important disease characteristics. In contrast, adaptive FSGS is associated with excessive nephron workload due to increased body size, reduced nephron capacity, or single glomerular hyperfiltration associated with certain diseases. Additional etiologies are now recognized as drivers of FSGS: high-penetrance genetic FSGS due to mutations in one of nearly 40 genes, virus-associated FSGS, and medication-associated FSGS. Emerging data support the identification of a sixth category: APOL1 risk allele-associated FSGS in individuals with sub-Saharan ancestry. The classification of a particular patient with FSGS relies on integration of findings from clinical history, laboratory testing, kidney biopsy, and in some patients, genetic testing. The kidney biopsy can be helpful, with clues provided by features on light microscopy (e.g, glomerular size, histologic variant of FSGS, microcystic tubular changes, and tubular hypertrophy), immunofluorescence (e.g, to rule out other primary glomerulopathies), and electron microscopy (e.g., extent of podocyte foot process effacement, podocyte microvillous transformation, and tubuloreticular inclusions). A complete assessment of renal histology is important for establishing the parenchymal setting of segmental glomerulosclerosis, distinguishing FSGS associated with one of many other glomerular diseases from the clinical-pathologic syndrome of FSGS. Genetic testing is beneficial in particular clinical settings. Identifying the etiology of FSGS guides selection of therapy and provides prognostic insight. Much progress has been made in our understanding of FSGS, but important outstanding issues remain, including the identity of the plasma factor believed to be responsible for primary FSGS, the value of routine implementation of genetic testing, and the identification of more effective and less toxic therapeutic interventions for FSGS.

Treatment Strategies of Adult Primary Focal Segmental Glomerulosclerosis: A Systematic Review Focusing on the Last Two Decades

Adult primary focal segmental glomerulosclerosis (FSGS) remains a therapeutic challenge for the treating physician. With the advent of novel immunosuppressive measures, our arsenal of therapeutic options increased considerably. The aim of this review was to summarize reports published over the last two decades which reported on treatment outcome. Most reports included patients with a steroid-resistant (SR) disease course, yet the cohort with the highest unmet need, since persistent nephrotic range proteinuria is associated with a poor renal prognosis and portends a high risk of developing end-stage renal disease. While in first-line treatment, steroid treatment remains the recommended standard with an overall remission rate of 50% and higher, optimal treatment strategies for steroid-dependent/multirelapsing (SD/MR) and SR patients have to be defined. In both entities, calcineurin inhibitors showed good efficacy, while mycophenolate mofetil was less effective in SR cases compared to those with SD/MR. The same was true for rituximab, a monoclonal antibody targeting B-cells. In resistant cases, addition of extracorporeal treatment options or treatment with alkylating agents may be considered. To shape the future for treatment of FSGS, international collaborations to conduct larger clinical trials are needed to identify potential novel efficacious immunosuppressive or immunomodulatory therapies.