Collagen type IV nephropathy: genetic heterogeneity examinations in affected Hungarian families.

The Col4A3, Col4A4 and Col4A5 collagen type IV genes are found to be mutated in Col IV nephropathy. In males with a mutation in the Col4A5 gene (X-linked Alport syndrome: XL-AS), progressive renal disease always develops. Female carriers with a mutation in the Col4A5 gene can develop thin basement membrane nephropathy (TBMN). Males and females who carry 1 Col4A3 or Col4A4 mutation usually manifest TBMN with nonprogressive hematuria. In the event of 2 Col4A3 or Col4A4 gene mutations, the autosomal recessive AS will develop. We examined the cosegregation pattern of hematuria in 20 families. The renal biopsies led to diagnoses of AS in 7 families, and of TBMN in 6 families. In 7 others, the diagnosis of familial hematuria (FHU) was based on the clinical symptoms. Markers of the ColA3/Col4A4 and Col4A5 loci (Col4A3: CA11 and D2S401; Col4A4: HaeIII/RFLP; and Col4A5: DXS456, 2B6 and 2B20) were used to assess their linkage to the clinical symptoms and morphological alterations. Maximum likelihood and the FASTLINK version of the linkage program were applied to compute logarithm of the odds (LOD) scores. A linkage to the Col4A3/Col4A4 genes was identified in 5 families (FHU in 3, AS in 2 families, 25%, LOD score range: 0.20-3.51). The XL-AS pattern of inheritance seemed likely with Col4A5 in 9 families (45%, LOD: 0.43-4.20); we found 4 disease-causative mutations by high-resolution melting curve analysis (LC480) and sequencing in this group. In 2 FHU families, the linkage to chromosomes 2 and X was precluded. Knowledge of the genetic background of Col IV nephropathy is essential to avoid the misdiagnosis of FHU and early AS. The allele frequencies, heterozygosity content and polymorphism information content of the applied STR markers on unrelated Hungarian normal and affected chromosomes 2 and X were also calculated.

Extracorporeal cytokine adsorption in septic shock: A proof of concept randomized, controlled pilot study.

BACKGROUND: The aim of this proof of concept, prospective, randomized pilot trial was to investigate the effects of extracorporeal cytokine removal (CytoSorb®) applied as a standalone treatment in patients with septic shock. METHODS: 20 patients with early (<24 h) onset of septic shock of medical origin, on mechanical ventilation, norepinephrine>10 µg/min, procalcitonin (PCT) > 3 ng/mL without the need for renal replacement therapy were randomized into CytoSorb (n = 10) and Control groups (n = 10). CytoSorb therapy lasted for 24 h. Clinical and laboratory data were recorded at baseline (T0), T12, T24, and T48 hours. RESULTS: Overall SOFA scores did not differ between the groups. In the CytoSorb-group norepinephrine requirements and PCT concentration decreased significantly (norepinephrine: CytoSorb: T0 = 0.54[IQR:0.20-1.22], T48 = 0.16[IQR:0.07-0.48], p = .016; Controls: T0 = 0.43[IQR:0.19-0.64], T48 = 0.25[IQR:0.08-0.65] µg/kg/min; PCT: CytoSorb: T0 median = 20.6[IQR: 6.5-144.5], T48 = 5.6[1.9-54.4], p = .004; Control: T0 = 13.2[7.6-47.8], T48 = 9.2[3.8-44.2]ng/mL). Big-endothelin-1 concentrations were also significantly lower in the CytoSorb group (CytoSorb: T0 = 1.3 ±â€¯0.6, *T24 = 1.0 ±â€¯0.4, T48 = 1.4 ±â€¯0.8, *p = .003; Control: T0 = 1.1 ±â€¯0.7, T24 = 1.1 ±â€¯0.6, T48 = 1.2 ±â€¯0.6 pmol/L, p = .115). There were no CytoSorb therapy-related adverse events. CONCLUSIONS: This is the first trial to investigate the effects of early extracorporeal cytokine adsorption treatment in septic shock applied without renal replacement therapy. It was found to be safe with significant effects on norepinephrine requirements, PCT and Big-endothelin-1 concentrations compared to controls. TRIAL REGISTRATION: The study has been registered on ClinicalTrials.gov, under the registration number of NCT02288975, registered 13 November 2014.

Efficient Targeted Next Generation Sequencing-Based Workflow for Differential Diagnosis of Alport-Related Disorders.

Alport syndrome (AS) is an inherited type IV collagen nephropathies characterized by microscopic hematuria during early childhood, the development of proteinuria and progression to end-stage renal disease. Since choosing the right therapy, even before the onset of proteinuria, can delay the onset of end-stage renal failure and improve life expectancy, the earliest possible differential diagnosis is desired. Practically, this means the identification of mutation(s) in COL4A3-A4-A5 genes. We used an efficient, next generation sequencing based workflow for simultaneous analysis of all three COL4A genes in three individuals and fourteen families involved by AS or showing different level of Alport-related symptoms. We successfully identified mutations in all investigated cases, including 14 unpublished mutations in our Hungarian cohort. We present an easy to use unified clinical/diagnostic terminology and workflow not only for X-linked but for autosomal AS, but also for Alport-related diseases. In families where a diagnosis has been established by molecular genetic analysis, the renal biopsy may be rendered unnecessary.

[Collagen type IV nephropathy: from thin basement membrane nephropathy to Alport syndrome]. / IV-es típusú kollagén nephropathiák: a vékony bazális membrán nephropathiától az Alport-szindrómáig.

INTRODUCTION: Collagen type IV nephropathy includes the Goodpasture syndrome, thin basement membrane nephropathy and the Alport syndrome. Mutations in the coding Col(IV)A3/A4 and Col(IV)A5 genes are probable causes of the latter two. Thin basement membrane nephropathy is mostly familial and has an autosomal dominant inheritance, at least 40% of the families have hematuria that co-segregates with the Col(IV)A3 and/or Col(IV)A4 loci. 85% of Alport syndrome cases are transmitted as an X-linked semidominant form due to Col(IV)A5 mutations. About 14% of Alport syndrome cases exhibit autosomal recessive, and 1% autosomal dominant inheritance, both caused by mutations in the Col(IV)A3 or Col(IV)A4 genes in boys and in girls. AIM: The co-segregation pattern of hematuria was examined in two families with thin basement membrane nephropathy and one family with the Alport syndrome, using short tandem repeat markers, spanning the Col(IV)A3/A4 and Col(IV)A5 loci to assess their linkage to the clinical symptoms and morphological alterations in the renal biopsy specimens. METHODS: Markers: Col(IV)A3: CAll and D2S401; Col(IV)A4: HaeIII/RFLP; and Col(IV)A5: DXS456, 2B6 and 2B20. RESULTS: The hematuria displayed autosomal dominant inheritance and co-segregated with Col(IV)A3 markers in one of the thin basement membrane nephropathy families. In the second, the hematuria did not segregate with the Col(IV)A3/A4 or Col(IV)A5 loci, suggesting the possibility of another genetic locus for the disease. The Alport syndrome exhibited autosomal recessive inheritance and did not link to Col(IV)A5 markers, and the Col(IV)A3/A4 markers were informative only in part. CONCLUSION: Knowledge of the inheritance and genetic background of collagen type IV nephropathy will be very important in the diagnostics and genetic counseling in the future.

[The incidence of renal diseases as diagnosed by biopsy in Hungary]. / A biopsziával kórismézett vesebetegségek gyakorisága a Dél-Alföldön.

AIM AND METHODS: The authors analysed the incidence of renal diseases as diagnosed by biopsy in the population living on the southern Great Hungarian Plain. 798 biopsy specimens were examined between 1990 and 2002. RESULTS: The most common diseases in decreasing order of frequency were IgA nephropathy (15%), membranous nephropathy (12%), thin-basement-membrane nephropathy (8%), minimal change nephropathy (7%), lupus glomerulonephritis (7%), focal sclerosis (6%), hypertensive kidney disease and arteriolosclerosis (5%), diabetic nephropathy (5%), and crescentic glomerulonephritis (4%). The most frequent diseases in decreasing order of frequency in children were minimal change nephropathy, thin-basement-membrane nephropathy, Henoch-Schönlein nephropathy and IgA nephropathy; in adults were IgA nephropathy, membranous nephropathy, lupus glomerulonephritis and thin-basement-membrane nephropathy; and in the elderly were membranous nephropathy, amyloidosis, crescentic glomerulonephritis and diabetic nephropathy. The incidence of the diseases differed significantly between the genders in IgA nephropathy, thin-basement-membrane nephropathy, lupus glomerulonephritis, chronic sclerosing nephropathy and Alport nephropathy. At the time of the biopsy, 69 patients were suffering from diabetes mellitus. 37 patients were diagnosed as having diabetic nephropathy, and 32 as having non-diabetic nephropathy. In 6 cases, the diabetic nephropathy was accompanied by other glomerular disorders. In more than half of the diabetic patients with non-diabetic nephropathy, membranous nephropathy or focal sclerosis was diagnosed. Crescentic glomerulonephritis was diagnosed on 30 occasions, which was due to vasculitis in 20 cases, proliferative glomerulonephritis in 7 cases and anti-glomerular-basement-membrane nephritis in 3 cases. In the middle-aged and the elderly, the renal disease was relatively often a consequence of systemic disease. CONCLUSION: The incidence and the gender distribution of renal diseases diagnosed by biopsy were similar to those reported by other European kidney biopsy centres. IgA nephropathy was the most frequent disease in the biopsy registry of the authors. The high incidence of thin-basement-membrane nephropathy seems to be related to consequent biopsy examinations of glomerular haematuria. In diabetics and the elderly, the diagnosis of the renal disease may be challenging.

Thin basement membrane nephropathy: diffuse and segmental types.

CONTEXT: Diffuse thinning of the glomerular basement membrane (GBM) is the ultrastructural diagnostic criterion of thin basement membrane nephropathy (TBMN). However, there is no consensus regarding what diagnosis should be made if the attenuation is segmental. OBJECTIVE: To develop a diagnostic approach to TBMN in cases with segmental GBM thinning. DESIGN: We compared the diagnostic sensitivities of 2 methods used for the quantitative expression of GBM width in a consecutive series of renal biopsies from 26 patients (median age, 36 years; range, 15 to 59 years) with dysmorphic hematuria (a variable degree of proteinuria in 19 patients), a thin GBM, and absence of other renal disease. The harmonic GBM width was determined from orthogonal intercepts, and the actual width in the thinnest loops was obtained by direct measurement. The GBM attenuation was categorized into diffuse or segmental types by conventional inspection. RESULTS: Segmental TBMN accounted for one third of the series. In neither type did the male patients have a higher harmonic mean GBM width than the female patients. Focal-global glomerulosclerosis was more common in diffuse TBMN. The laborious orthogonal intercept method proved insensitive for the verification of segmental TBMN, whereas the much simpler direct measurement technique captured all the cases. CONCLUSIONS: A considerable number of patients with TBMN display segmental GBM attenuation. Because the routine criterion excludes these cases from the diagnosis, we propose to define TBMN as a clinicopathologic entity of dysmorphic hematuria and a diffusely or segmentally thinned GBM confirmed by the direct measurement technique.