Delphi: A Democratic and Cost-Effective Method of Consensus Generation in Transplantation.

The Thrombotic Microangiopathy Banff Working Group (TMA-BWG) was formed in 2015 to survey current practices and develop minimum diagnostic criteria (MDC) for renal transplant TMA (Tx-TMA). To generate consensus among pathologists and nephrologists, the TMA BWG designed a 3-Phase study. Phase I of the study is presented here. Using the Delphi methodology, 23 panelists with >3 years of diagnostic experience with Tx-TMA pathology listed their MDC suggesting light, immunofluorescence, and electron microscopy lesions, clinical and laboratory information, and differential diagnoses. Nine rounds (R) of consensus resulted in MDC validated during two Rs using online evaluation of whole slide digital images of 37 biopsies (28 TMA, 9 non-TMA). Starting with 338 criteria the process resulted in 24 criteria and 8 differential diagnoses including 18 pathologic, 2 clinical, and 4 laboratory criteria. Results show that 3/4 of the panelists agreed on the diagnosis of 3/4 of cases. The process also allowed definition refinement for 4 light and 4 electron microscopy lesions. For the first time in Banff classification, the Delphi methodology was used to generate consensus. The study shows that Delphi is a democratic and cost-effective method allowing rapid consensus generation among numerous physicians dealing with large number of criteria in transplantation.

Clinical and histopathological characteristics of COL4A3 c.2881+1G>A variant causing Alport spectrum disorders in Croatian population.

Alport syndrome (AS) and thin basement membrane nephropathy (TBMN) are part of the spectrum of kidney disorders caused by pathogenic variants in α3, α4, or α5 chains of the collagen type IV, the major structural component of the glomerular basement membrane (GBM). Using targeted next-generation sequencing (NGS), 34 AS/TBMN patients (58.8% male) from 12 unrelated families were found positive for heterozygous c.2881+1G>A variant of the COL4A3gene, that is considered disease-causing. All patients were from the continental or island part of Croatia. Clinical, laboratory, and histopathological data collected from the medical records were analyzed and compared to understand the clinical course and prognosis of the affected patients. At the time of biopsy or first clinical evaluation, the mean age was 31 years (median: 35 years; range: 1 - 72 years). Hematuria was present in 33 patients (97.1%) and 19 (55.9%) patients had proteinuria. There were 6 (17.6%) patients with hearing loss, 4 (11.8%) with ocular lesions, and 11 (32.4%) with hypertension. Twenty-three (67.6%) patients had proteinuria at follow-up, and 5 (14.7%) patients with the median age of 48 years (range: 27-55) progressed to kidney failure, started dialysis, or underwent kidney transplantation. Of the 13 patients who underwent kidney biopsy, 4 (30.8%) developed focal segmental glomerulosclerosis (FSGS), and 8 (66.7%) showed lamellation of the GBM, including all patients with FSGS. It is essential to conduct a detailed analysis of each collagen type IV genetic variant to optimize the prognosis and therapeutic approach for affected patients.

Resistant and Relapsing Collapsing Glomerulopathy Successfully Treated with Rituximab-A Case Report.

Collapsing glomerulopathy (CG) or collapsing focal segmental glomerulosclerosis (cFSGS) is an aggressive disease with a high tendency of progression to end-stage renal disease due to common resistance to conventional immunosuppressants. Rituximab (RTX), a monoclonal antibody against CD20 B cells, showed some benefit in the treatment of CG. We are reporting about female patients with an idiopathic form of CG presenting with nephrotic syndrome (NS) and renal insufficiency resistant to several immunosuppressive agents such as steroids (ST), calcineurin inhibitors (CNI), and cyclophosphamide (CYC). This multidrug-resistant disease responded to RTX with complete remission. Forty-four months after initial RTX administration, a relapse of CG with severe NS and acute renal insufficiency occurred. Repeated application of RTX led to complete remission again. To the best of our knowledge, we are reporting the first case of the relapsing multidrug-resistant form of CG, which responded to RTX. Current data about the treatment of CG with RTX is lacking and is based on rare case reports and small case series. Thus, our report can contribute to determining the role of RTX in the treatment of CG.

PULMONARY HEMORRHAGE AND CRESCENTIC GLOMERULONEPHRITIS IN A PATIENT WITH SEROPOSITIVE ANTI-GLOMERULAR BASEMENT MEMBRANE DISEASE AND ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODIES.

Anti-glomerular basement membrane (anti-GBM) disease is an acute and life-threatening systemic autoimmune disorder. The coexistence of circulating anti-neutrophil cytoplasmic antibodies (ANCA) and anti-GBM disease, the so-called double-positive disease (DPD), is exceptionally rare. We report a unique case of DPD manifesting as pulmonary-renal syndrome (PRS) in a 46-year-old woman who first presented with clinical and radiological suspicion of pneumonia. Chest computed tomography scan later revealed bilateral alveolar hemorrhage. Kidney biopsy showed necrotizing crescentic (100% glomeruli) glomerulonephritis. On immunofluorescence microscopy, glomeruli were global linear positive for IgG, confirming anti-GBM disease. Double positivity was detected for circulating anti-myeloperoxidase ANCA (p-ANCA) and anti-GBM antibodies. Acute renal failure evolved rapidly. Therapeutic plasma exchange (TPE) and hemodialysis (HD) were initiated early in combination with intravenous pulse corticosteroid therapy followed by oral methylprednisolone and cyclophosphamide. Pulmonary hemorrhage resolved, but renal function could not be preserved. The patient remains HD dependent. This case report highlights that pulmonary symptomatology may be the leading clinical presentation of PRS, with initially normal renal function at DPD onset. Early recognition and diagnosis are therefore crucial to timely clinical intervention. The role of prompt kidney biopsy and initiation of TPE and HD in PRS must not be underestimated.

Clinical and pathohistological characteristics of Alport spectrum disorder caused by COL4A4 mutation c.193-2A>C: a case series.

AIM: To present the pathohistological and clinical characteristics of five Croatian families with Alport spectrum disorders caused by splice acceptor pathogenic variant c.193-2A>C in COL4A4 at the genomic position chr2:227985866. METHODS: The study enrolled five probands with kidney biopsy analysis and five family members. Mutation screening was performed with Illumina MiSeq platform. The pathogenic variant was confirmed with standard dye-terminator sequencing. RESULTS: The only homozygous patient, aged two, had proteinuria and hematuria with preserved kidney function and no extrarenal manifestations. This patient had changes characteristic for Alport syndrome observed on electron microscopy of the kidney biopsy. In the heterozygous group, six patients had hematuria, four biopsied probands had proteinuria, and only one had moderately reduced kidney function. Heterozygous probands had variable kidney biopsy findings. Three patients had thin glomerular basement membrane nephropathy visible on electron microscopy and focal segmental glomerulosclerosis on light microscopy, two of them with focal lamellation on electron microscopy. One heterozygous patient had changes characteristic for Alport syndrome on electron microscopy without focal segmental glomerulosclerosis. CONCLUSION: The homozygous patient had hematuria and proteinuria with preserved kidney function. The heterozygous patients presented with reasonably mild clinical phenotype and variable pathohistological findings.

Expression Pattern of α-Tubulin, Inversin and Its Target Dishevelled-1 and Morphology of Primary Cilia in Normal Human Kidney Development and Diseases.

The spatiotemporal expression of α-tubulin, inversin and dishevelled-1 (DVL-1) proteins associated with the Wnt-signaling pathway, and primary cilia morphology were analyzed in developing kidneys (14th-38th developmental weeks), healthy postnatal (1.5- and 7-years old) and pathologically changed human kidneys, including multicystic dysplastic kidneys (MCDK), focal segmental glomerulosclerosis (FSGS) and nephrotic syndrome of the Finnish type (CNF). The analysis was performed by double immunofluorescence, electron microscopy, semiquantitative and statistical methods. Cytoplasmic co-expression of α-tubulin, inversin and DVL-1 was observed in the proximal convoluted tubules (pct), distal convoluted tubules (dct) and glomeruli (g) of analyzed tissues. During kidney development, the overall expression of α-tubulin, inversin and DVL-1 decreased, while in the postnatal period slightly increased. The highest expressions of α-tubulin and inversin characterized dct and g, while high DVL-1 characterized pct. α-tubulin, inversin and DVL-1 expression pattern in MCDK, FSGS and CNF kidneys significantly differed from the healthy control. Compared to healthy kidneys, pathologically changed kidneys had dysmorphic primary cilia. Different expression dynamics of α-tubulin, inversin and DVL-1 during kidney development could indicate that switch between the canonical and noncanonical Wnt-signaling is essential for normal kidney morphogenesis. In contrast, their disturbed expression in pathological kidneys might be associated with abnormal primary cilia, leading to chronic kidney diseases.

Autosomal recessive Alport syndrome caused by a novel COL4A4 splice site mutation: a case report.

Alport syndrome (AS) is a genetically heterogenic, structural disorder of the glomerular basement membrane (GBM) due to the mutation of COL4A3, COL4A4, or COL4A5 genes, which clinically presents as progressive hematuric nephritis with ultrastructural changes of the GBM, high tone sensorineural hearing loss, and ocular lesions. About 15% of AS cases have autosomal mutations of COL4A3 and COL4A4 genes, including homozygous and compound heterozygous mutations. Here, we present a case of a two-year-old boy with autosomal recessive Alport syndrome (ARAS) caused by a novel c.193-2A>C COL4A4 mutation. The patient had a delayed motor and sensory development coupled with speech and language delay, megalencephaly, hematuria and proteinuria, and normal tonal audiogram and ophthalmology exam. Extensive genetic, metabolic, and neurologic workup performed at the age of 10 months was unremarkable and patient's megalencephaly was described as familial benign megalencephaly. Kidney biopsy analysis showed characteristic signs of AS. Mutations screening with use of Illumina MiSeq platform revealed that the patient was homozygous for a newly discovered splice acceptor pathogenic variant c.193-2A>C found in COL4A4 at the genomic position chr2:227985866 and both parents were heterozygous carriers. The genetic heterogeneity of AS makes the diagnostic process challenging. Although renal biopsy provides information about the characteristic GBM changes and the degree of renal parenchyma damage (interstitial fibrosis and tubular atrophy ratio), genetic testing is a more sensitive and specific method that also gives insight into potential disease severity and clinical course, and provides the basis for genetic counseling.

Reproducibility of the Oxford classification of immunoglobulin A nephropathy, impact of biopsy scoring on treatment allocation and clinical relevance of disagreements: evidence from the VALidation of IGA study cohort.

BACKGROUND: The VALidation of IGA (VALIGA) study investigated the utility of the Oxford Classification of immunoglobulin A nephropathy (IgAN) in 1147 patients from 13 European countries. Methods. Biopsies were scored by local pathologists followed by central review in Oxford. We had two distinct objectives: to assess how closely pathology findings were associated with the decision to give corticosteroid/immunosuppressive (CS/IS) treatments, and to determine the impact of differences in MEST-C scoring between central and local pathologists on the clinical value of the Oxford Classification. We tested for each lesion the associations between the type of agreement (local and central pathologists scoring absent, local present and central absent, local absent and central present, both scoring present) with the initial clinical assessment, as well as long-term outcomes in those patients who did not receive CS/IS. RESULTS: All glomerular lesions (M, E, C and S) assessed by local pathologists were independently associated with the decision to administer CS/IS therapy, while the severity of tubulointerstitial lesions was not. Reproducibility between local and central pathologists was moderate for S (segmental sclerosis) and T (tubular atrophy/interstitial fibrosis), and poor for M (mesangial hypercellularity), E (endocapillary hypercellularity) and C (crescents). Local pathologists found statistically more of each lesion, except for the S lesion, which was more frequent with central review. Disagreements were more likely to occur when the proportion of glomeruli affected was low. The M lesion, assessed by central pathologists, correlated better with the severity of the disease at presentation and discriminated better with outcomes. In contrast, the E lesion, evaluated by local pathologists, correlated better with the clinical presentation and outcomes when compared with central review. Both C and S lesions, when discordant between local and central pathologists, had a clinical phenotype intermediate to double absent lesions (milder disease) and double present (more severe). CONCLUSION: We conclude that differences in the scoring of MEST-C criteria between local pathologists and a central reviewer have a significant impact on the prognostic value of the Oxford Classification. Since the decision to offer immunosuppressive therapy in this cohort was intimately associated with the MEST-C score, this study indicates a need for a more detailed guidance for pathologists in the scoring of IgAN biopsies.

IgM as a novel predictor of disease progression in secondary focal segmental glomerulosclerosis.

AIM: To determine the role of immunoglobulin M (IgM) deposits in clinical manifestations, disease outcome, and treatment response of idiopathic and secondary focal segmental glomerulosclerosis (FSGS). METHODS: Kidney biopsy specimens of 171 patients diagnosed with FSGS (primary and secondary) and 50 control patients were retrospectively included in the study. For each patient, clinical and outcome data were obtained and compared to morphological parameters, including immunofluorescence analysis of mesangial IgM and complement 3 (C3) deposits analyzed on kidney biopsy samples. RESULTS: There were significant positive correlations between IgM and C3 deposition in secondary FSGS (P<0.001) and between IgM and mesangial deposits detected by electron microscopy in secondary FSGS (P=0.015), which indicated that higher IgM deposition correlated with higher C3 deposition and mesangial deposits only in secondary FSGS. Patients with secondary FSGS and the deposition of IgM showed inferior renal outcomes at earlier time points in comparison with patients with negative IgM expression (P=0.022). CONCLUSIONS: We detected a positive correlation between IgM and C3 in secondary FSGS. The association between IgM deposition and worse renal outcome in secondary FSGS indicates that IgM may play a role in the progression of this disease.

ELF5 transcription factor expression during gestation in humans and rats - an immunohistochemical analysis.

OBJECTIVE: The purpose of this study was to measure immunohistochemically the expression of ELF5 protein in term human and rat placentas and in human placentas associated with gestational diabetes (GD) and intrauterine growth restriction (IUGR). METHODS: The results were quantitated stereologically using the stereological variable of volume density. A semiquantitative analysis was performed independently by a certified pathologist. RESULTS: Total expression of ELF5 protein was higher in pathological pregnancies than in corresponding control term placentas, with both methods of quantifications showing similar results. In addition, ELF5 expression was also higher in connective tissue and blood vessels in chorionic villi in IUGR placentas (but not in GD placentas) compared to healthy controls. ELF5 is higher in placenta as a whole and in most of its components in both pathologies. The two exceptions are chorionic plates in IUGR and decidua in GD, where its expression is lower than in healthy controls. CONCLUSIONS: We have shown that IUGR and GD are associated with significantly increased levels of ELF5 protein in placentas, which suggests that ELF5 may play an important role in normal placentation. However, these are term placentas and to study ELF5 in premature births would give better insight into human placentation in health and disease.

Non-diabetic renal disease in Croatian patients with type 2 diabetes mellitus.

AIM: Our study aimed to examine the prevalence of non-diabetic renal disease in selected patients with type 2 diabetes mellitus and to determine important risk factors for non-diabetic renal disease. METHODS: We conducted retrospective analysis of clinical, laboratory and pathohistological data of type 2 diabetes mellitus patients in whom renal biopsies were performed from January 2004 to February 2013 at Dubrava University Hospital Zagreb Croatia (n=80). RESULTS: According to renal biopsy findings, isolated diabetic nephropathy was found in 46.25%, non-diabetic renal disease superimposed on diabetic nephropathy in 17.5% and isolated non-diabetic renal disease in 36.25% of the patients. The most common non-diabetic renal diseases found were: membranous nephropathy, followed by IgA nephropathy and focal segmental glomerulosclerosis. In univariate analysis shorter duration of diabetes, independence of insulin therapy, lower levels of HbA1c and absence of diabetic retinopathy were found to be significant clinical predictors of non-diabetic renal disease. In multivariate analysis only independence of insulin therapy (OR 4.418, 95%CI=1.477-13.216) and absence of diabetic retinopathy (OR 5.579, 95%CI=1.788-17.404) were independent predictors of non-diabetic renal disease. CONCLUSIONS: This study confirmed usefulness of renal biopsy in patients with type 2 diabetes mellitus, due to the high prevalence of non-diabetic renal disease found. Since non-diabetic renal disease are potentially curable, we should consider renal biopsy in selected type 2 diabetes mellitus patients with renal involvement, especially in those with absence of diabetic retinopathy and independence of insulin therapy.

Epidemiologic data of adult native biopsy-proven renal diseases in Croatia.

PURPOSE: There is a paucity of epidemiological data on biopsy-proven renal disease in Croatia. The purpose of this report is a review of clinical and histological data, over a period of 15 years, from the single biggest adult native renal biopsy center in Croatia. METHODS: This report includes data from 922 adult native renal biopsies in patients referred from the whole country and performed in our center from 1996 till February 2012. Data on age, gender, serum creatinine, urine sediment, 24-h proteinuria, clinical syndrome and histological diagnosis were collected and analyzed retrospectively. In all patients, light, immunofluorescence and electron microscopic analysis was performed. RESULTS: The median age of the patients was 48 years (interquartile range 36-59 years), and the majority of patients were men (57.8 %). The most common indication for renal biopsy was nephrotic syndrome (40.3 %) followed by asymptomatic urinary abnormalities (31.7 %). The most common biopsy-proven renal disease in total was IgA glomerulonephritis (19.3 %), followed by focal segmental glomerulosclerosis (FSGS) (15.8 %) and membranous glomerulonephritis (9.2 %). In men, similar results were found, while in women, the most common were hereditary nephritis (13.4 %), FSGS (12.9 %) and connective tissue disease-related glomerular disorders (11.6 %). CONCLUSION: The presented data are an important contribution to the better understanding of the epidemiology of biopsy-proven renal disease in Croatia and Europe throughout comparison with other registry data. This data should be the basis for the formation of Croatian Registry of Renal Biopsies.