Soumeya Bekri

The inflammatory C-reactive protein is increased in both liver and adipose tissue in severely obese patients independently from metabolic syndrome, Type 2 diabetes, and NASH.

OBJECTIVE:C-Reactive Protein (CRP), a nonspecific marker of inflammation that is moderately elevated in obesity, metabolic syndrome (MS), and type 2 diabetes, has been proposed as a surrogate marker of nonalcoholic steatohepatitis (NASH). Its clinical usefulness in the diagnosis of NASH was evaluated in severely obese patients without or with MS, diabetes, and NASH and the potential roles of the liver and of the adipose tissue in CRP production were characterized.METHODS:Severely obese patients without NASH (without MS [N = 13], with MS [N = 11], or with MS and diabetes [N = 7]) and with NASH (without [N = 8] or with [N = 7] MS) were studied. For each patient, liver and adipose tissue biopsies were collected during a bariatric surgery and were used to determine the CRP gene expression by real-time PCR. The role of interleukin-6 (IL6) and lipopolysaccharide in CRP expression was also evaluated in subcutaneous adipose tissue obtained during cosmetic abdominoplasty.RESULTS:Plasma CRP levels were elevated in severely obese patients independently from the presence or absence of MS, diabetes, or NASH. CRP gene expression was not only increased in livers but also in adipose tissues of obese patients compared with controls subjects. In human adipose tissue, CRP mRNA levels were positively correlated with those of IL-6 and the CRP expression was enhanced in vitro by IL-6 and lipopolysaccharide.CONCLUSION:Plasma CRP levels are not predictive of the diagnosis of NASH in severely obese patients. The liver but also the adipose tissue can produce CRP, a process which could be dependent on IL6. Therefore, both tissues might contribute to the elevated plasma CRP levels found in obesity. In addition, the large amount of body fat may well produce an important part of the circulating CRP, further limiting its clinical usefulness in the evaluation of NASH in severely obese patients.

Fabry Disease in Patients with End-Stage Renal Failure: The Potential Benefits of Screening

Background/Aims: α-Galactosidase A (α-GLA) deficiency (Fabry disease) is an X-linked lysosomal storage disorder. The associated visceral complications are progressive and multiorgan; renal involvement is common, usually leading to end-stage renal failure (ESRF). The reported benefits of specific enzyme replacement therapy (ERT) indicate the importance of screening for Fabry disease in high-risk populations, as this approach should make it possible to identify other family members with little or no clinical features of the disease, and for them to be considered for early preventive treatment. Methods: We screened for Fabry disease in 106 patients on hemodialysis in our hospital-based hemodialysis unit. We did this by measuring α-GLA enzyme activity in blood leukocytes taken from each patient and we then carried out gene analysis when indicated. Results: We were able to discover 1 patient with low residual α-GLA activity (a prevalence of 0.94%). α-GLA gene analysis identified a point mutation within the coding region producing a N215S amino acid substitution in the protein. Among the relatives of this index case, molecular testing found 7 family members with the same N215S α-GLA mutation. Of these, 3 had reduced α-GLA activity and clinical features of Fabry disease, and for which ERT was subsequently given. Conclusion: Screening for Fabry disease is simple and although the yield is small, it is potentially significant and of possible benefit to the relatives of affected cases in this ‘at-risk’ ESRF population, many of who do not have a clear renal diagnosis.

A new workflow for proteomic analysis of urinary exosomes and assessment in cystinuria patients.

Cystinuria is a purely renal, rare genetic disease caused by mutations in cystine transporter genes and characterized by defective cystine reabsorption leading to kidney stones. In 14% of cases, patients undergo nephrectomy, but given the difficulty to predict the evolution of the disease, the identification of markers of kidney damage would improve the follow-up of patients with a higher risk. The aim of the present study is to develop a robust, reproducible, and noninvasive methodology for proteomic analysis of urinary exosomes using high resolution mass spectrometry. A clinical pilot study conducted on eight cystinuria patients versus 10 controls highlighted 165 proteins, of which 38 were up-regulated, that separate cystinuria patients from controls and further discriminate between severe and moderate forms of the disease. These proteins include markers of kidney injury, circulating proteins, and a neutrophil signature. Analysis of selected proteins by immunobloting, performed on six additional cystinuria patients, validated the mass spectrometry data. To our knowledge, this is the first successful proteomic study in cystinuria unmasking the potential role of inflammation in this disease. The workflow we have developed is applicable to investigate urinary exosomes in different renal diseases and to search for diagnostic/prognostic markers. Data are available via ProteomeXchange with identifier PXD001430.