Dolores López

Renal injury in the extremely obese patients with normal renal function

We studied the glomerular architecture in renal biopsies of 95 patients undergoing bariatric surgery for extreme obesity but whose renal function was normal. The comparison group was 40 control patients having protocol biopsies. These latter patients had normal weight and renal function, were non-diabetic, non-hypertensive, and were undergoing nephrectomy or donating a kidney. Logistic regression models determined associations between the clinical and biochemical variables and glomerular lesions. Arterial hypertension, sleep apnea syndrome (SAS), and microalbuminuria were prevalent in the obese patients, as was hyperglycemia to a lesser extent. Focal and segmental glomerulosclerosis was present in only five extremely obese (EO) patients but absent in controls. Increased mesangial matrix, podocyte hypertrophy, mesangial cell proliferation, and glomerulomegaly were more frequent in the obese cohort than in the control group. Body mass index was a significant independent risk factor associated with glomerular lesions in all 135 patients and in the 95 EO patients, whereas SAS was associated with glomerulomegaly only in the EO. Our study shows that EO patients who lack overt clinical renal symptoms have a variety of glomerular abnormalities that correlate with body mass.

Cyclin D1 overexpression in non-small cell lung carcinoma : Correlation with Ki67 labelling index and poor cytoplasmic differentiation

Cyclin D1 is part of the molecular system regulating the cell cycle G1 to S transition point. Its overexpression, a common finding in carcinomas of the breast, oesophagus, and head and neck, has also been demonstrated in a high percentage of non‐small cell lung carcinomas (NSCLCs). The role of cyclin D1 in NSCLC has been studied by correlating its immunoreactivity with the Ki67 labelling index in paraffin‐embedded, autoclaved surgical samples of 56 NSCLC cases. In addition, flow cytometric determination of ploidy and cell cycle status was carried out on 172 fresh tumour samples from the same cases. Twenty‐four (42·8 per cent) NSCLCs showed positive cyclin D1 immunostaining, a finding which showed no relationship to ploidy pattern, cell cycle phase, histological subtype, or lymph node metastasis, but was significantly associated with the Ki67 labelling index (P=0·03) and with poor cytoplasmic differentiation (P=0·01). Cyclin D1‐positive nuclei were abundant in poorly differentiated zones and absent in the best differentiated areas, particularly in heavily keratinized fields. These data indicate that in NSCLC, cyclin D1 overexpression is not only associated with a high cell proliferation rate, but also seems to play a role in the process of tumour differentiation.

Differential expression of α-synuclein isoforms in dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is characterized by the widespread presence of Lewy bodies (LBs) in the brain. α‐Synuclein, the main component of LBs, is expressed as two main isoforms (112 and 140), but little is known about their differential expression in the brain. We compared α‐synuclein 112 and α‐synuclein 140 expression levels in the prefrontal cortices of six DLB patients, eight Alzheimer disease (AD) patients, and six control subjects. Relative α‐synuclein 112 and α‐synuclein 140 expression levels were determined by real‐time polymerase chain reaction with competimer technology using a LightCycler System. Whereas total α‐synuclein levels were just marginally elevated in DLB in comparison with the other groups, α‐synuclein 112 was seen to be markedly increased in DLB compared with AD cases and controls. In contrast, α‐synuclein 140 levels were significantly diminished in both neurodegenerative disorders in comparison with controls. These results show differential overexpression of α‐synuclein 112 in DLB, a finding that could be of importance in DLB pathogenesis.

Role of CD44 in the invasiveness of glioblastoma multiforme and the noninvasiveness of meningioma : an immunohistochemistry study

CD44 is a polymorphic family of cell adhesion molecules that seems to be instrumental in the mechanism of tumor invasion and metastasis. Tumor cell expression of CD44, or lack thereof, may be one of the factors conditioning the highly disparate ability to penetrate the brain extracellular matrix (ECM) exhibited by glioblastoma multiforme (GM) and conventional meningioma. To assess the presence of CD44 in these two tumor types we have immunohistochemically investigated the expression of CD44 standard form (CD44s) and the variant isoforms containing the domain encoded by variant exon 3 (CD44v3) and variant exon 6 (CD44v6) in paraffin-embedded tissue from 10 conventional meningiomas and 10 GMs. A CD44s-/CD44v-phenotype was discerned in the meningioma cases, whereas GMs featured a CD44s+/CD44v- expression profile. Consequently, the growth patterns of meningioma and GM seem to be, at least in part, a reflection of their CD44 expression status. Paucity of CD44 in meningioma cells would render them unable to infiltrate the brain ECM, whereas CD44-rich glioma cells would successfully migrate through it. Conversely, lack of CD44v expression would contribute to explain the lack of metastatic potential characterizing both conventional meningioma and GM.

Is there a need for changes in renal biopsy criteria in proteinuria in type 2 diabetes

Criteria for renal biopsy in proteinuric type 2 diabetes mellitus (T2DM) patients have been not defined. Usually criteria for renal biopsy in type 1 diabetes mellitus (T1DM) are used (microhaematuria, absence of diabetic retinopathy (DR), uncharacteristic change in renal function or immunological abnormalities). The aim of this study was to reconsider the indications for renal biopsy in T2DM using T1DM criteria, to determine whether they are useful in identifying patients with potentially treatable lesions. We studied 127 proteinuric patients with T2DM. Renal biopsy was performed in 35 who met the criteria for biopsy. Biopsy revealed diabetic glomerulopathy (DG) in 29 (83%) (in three associated with nondiabetic renal disease), immunoglobulin A (IgA) glomerulonephritis in three, focal glomerulosclerosis in one and normal glomeruli in two. DG was diagnosed in 17 (74%) of the patients without DR, in 18 (78%) of the patients with microhaematuria and in 10 (67%) of the patients with microhaematuria and without DR. All patients with DR had DG alone, except three with sudden unexpected changes in renal function. We conclude that DG is the most commonly found renal lesion in T2DM patients with proteinuria biopsied according to T1DM criteria, even in patients with microhaematuria or without retinopathy. Thus, these biopsy criteria are not useful in identifying patients with potentially treatable other renal diseases.

Obesity, inflammation, and kidney disease

Obesity and extreme obesity are associated with a wide range of well known comorbidities (cardiovascular disease, dyslipidemia, hypertension, diabetes mellitus, metabolic syndrome). Recently, the association between obesity and renal involvement has been accepted since several epidemiological and pathological studies support this relationship. However, the physiopathological mechanism of this association is not completely understood. Different mechanisms have been implicated in the production of these renal lesions. Between them, metabolic alterations and inflammatory adipocytokines have been suggested. This paper is a review of the association between inflammatory adipocytokines or metabolic syndrome with renal involvement. We also briefly report our experience in a cohort of extremely obese patients.

Messenger RNA expression of B7-1 and NPHS1 in urinary sediment could be useful to differentiate between minimal change disease and focal segmental glomerulosclerosis in adult patients

BACKGROUND Podocyte proteins are involved in the pathogenesis of glomerular kidney disease (GKD). However, there is little information on messenger RNA (mRNA) expression patterns of B7-1 and NPHS1 in urinary sediment of patients with GKD. The objective of this study was to analyse the gene expression of B7-1 in urinary sediment and correlate it with the expression of podocyte-specific genes in patients with GKD. METHODS Adult patients with proliferative and non-proliferative GKD, proteinuria and stable renal function, were included. A group of healthy subjects was used to determine normal levels of urinary markers and to obtain reference RNA. Biochemical, clinical and experimental procedures included measurement of creatinine level and total urinary protein, renal biopsy, identification of urinary podocytes, gene expression analysis of B7-1, NPHS1, NPHS2 and SyNPO genes and urinary B7-1 protein analysis by enzyme-linked immunosorbent assay. RESULTS Between June 2006 and November 2009, 69 patients with GKD (median age: 46 ± 15 years, 64% men) and 14 healthy subjects (median age: 34 ± 12 years, 43% men) were included. In both groups, urinary mRNA levels of B7-1 and NPHS1 were significantly higher in patients with GKD compared to healthy subjects (P = 0.050 and P = 0.008, respectively). Regarding GKD subtypes, patients with focal segmental glomerulosclerosis (FSGS), but not patients with minimal change disease (MCD), had a significantly higher mRNA expression of B7-1 and NPHS1 than healthy subjects (P = 0.012 and P = 0.030, respectively). Patients with MCD had a significantly lower NPHS1 mRNA expression than patients with FSGS (P = 0.012). The B7-1:NPHS1 urinary mRNA ratio was significantly higher in patients with MCD compared with patients with FSGS (P = 0.027). CONCLUSION mRNA expression analysis of B7-1 and NPHS1 in urinary sediment may be useful to differentiate between different histologic subtypes of GKD, particularly between MCD and FSGS.

A variable poly‐T sequence modulates α‐synuclein isoform expression and is associated with aging

α‐Synuclein, the main component of proteinaceous inclusions in synucleinopathies, is centrally involved in aggregation processes preceding Lewy body formation. Here we describe a new α‐synuclein gene poly‐T polymorphism that is situated upstream to exon 3 and consists of three different alleles. A correlation between poly‐T length and expression of α‐synuclein 126 mRNA, an isoform lacking exon 3, was detected in the human cerebral cortex. Specifically, when compared with the most frequent 7T/7T genotype, the shortest poly‐T stretch (5T) was associated with the lowest α‐synuclein 126 expression levels, whereas the longest poly‐T stretch (12T) was accompanied by the highest α‐synuclein 126 expression levels. Thus, three different expression‐level‐specific genotypes, with 5T+ genotypes as low α‐synuclein 126 expression genotypes and 12T+ genotypes as high α‐synuclein 126 expression genotypes, could be established. Poly‐T genotype distributions were also analyzed in a healthy control population. Age‐dependent variations in this distribution were observed and showed accumulation of low α‐synuclein 126 expression genotypes at ages under 60 years and high α‐synuclein 126 expression genotypes at ages over 80 years. To determine human specificity of the variable poly‐T strech, the mouse α‐synuclein gene sequence was analyzed. Although α‐synuclein is very well conserved in vertebrates, the poly‐T sequence was found to be absent in mice, and an α‐synuclein 126 mouse homologue could not be detected. In conclusion, this newly identified poly‐T polymorphism is a human‐specific sequence; its length influences α‐synuclein 126 expression levels; and, finally, it seems to exert a specific influence on normal aging.

Anti-factor H antibody affecting factor H cofactor activity in a patient with dense deposit disease

Complement alternative pathway dysregulation seems to be the pathophysiological basis of Dense Deposit Disease (DDD). Here, we describe a monoclonal anti-factor H (FH) autoantibody in a woman diagnosed with DDD with a monoclonal gammapathy. Enzyme-linked immunosorbent assays evidenced the presence of anti-FH antibodies in the patients serum and showed that they were associated with the monoclonal IgG-λ fraction. These autoantibodies recognize the N-terminal region of FH and interfere with its regulatory function. In summary, in the DDD patient described here, the activation of complement alternative pathway was favoured by the presence of anti-FH autoantibodies that recognize the regulatory region of this protein and impede its function and which could ultimately cause the glomerulopathy.

Uromodulin and α1-Antitrypsin Urinary Peptide Analysis to Differentiate Glomerular Kidney Diseases

Background/Aims: Glomerular kidney disease (GKD) is suspected in patients based on proteinuria, but its diagnosis relies primarily on renal biopsy. We used urine peptide profiling as a noninvasive means to link GKD-associated changes to each glomerular entity. Methods: Urinary peptide profiles of 60 biopsy-proven glomerular patients and 14 controls were analyzed by combining magnetic bead peptide enrichment, MALDI-TOF MS analysis, and ClinProTools v2.0 to select differential peptides. Tentative identification of the differential peptides was carried out by HPLC-MS/MS. Results: The HPLC-MS/MS results suggest that uromodulin (UMOD; m/z: 1682, 1898 and 1913) and α1-antitrypsin (A1AT; m/z: 1945, 2392 and 2505) are differentially expressed urinary peptides that distinguish between GKD patients and healthy subjects. Low UMOD and high A1AT peptide abundance was observed in 80–92% of patients with GKD. Proliferative forms of GKD were distinguished from nonproliferative forms, based on a combination of UMOD and A1AT peptides. Nonproliferative forms correlated with higher A1AT peptide levels – focal segmental glomerulosclerosis was linked more closely to high levels of the m/z 1945 peptide than minimal change disease. Conclusion: We describe a workflow – urinary peptide profiling coupled with histological findings – that can be used to distinguish GKD accurately and noninvasively, particularly its nonproliferative forms.