Proteomic approach for identification of IgA nephropathy-related biomarkers in urine.

Proteinuria is often used as a surrogate marker in monitoring and predicting outcome in patients with chronic kidney diseases, but it is non-specific. IgAN belongs to the most common primary glomerulonephritis worldwide with serious prognosis. The main aim of this work was to assess differences in urine proteins in patients with IgA nephropathy and to identify abnormal proteins as potential biomarkers of IgA nephropathy or the renal disease. In our pilot project, we selected 20 patients and compared them with 20 healthy volunteers. Protein quantification was performed using iTRAQ (isobaric tag for relative and absolute quantitation) labeling method. The peptides were separated by the isoelectric focusing method (IEF) and nano-LC with C18 column and identified by mass spectrometry using MALDI-TOF/TOF MS. Proteins´ lists obtained from IEF-LC-MS-MS/MS analysis were combined and contained 201 proteins. It was found out that 113 proteins were common in both experiments. 30 urinary proteins were significantly up- or down-regulated in patients with IgA nephropathy. We characterized potential biomarkers such as alpha-1-antitrypsin, apolipoprotein A-I, CD44 antigen or kininogen. Potential biomarkers of IgAN should be validated in further studies.

[Peritoneal dialysis and its modification in the treatment of chronic renal failure]. / Peritoneální dialýza a její modifikace v lécbe chronického selhání ledvin.

Three methods can be used to treat chronic renal failure - haemodialysis, peritoneal dialysis and renal transplantation (from a living donor or transplantation of a cadaver kidney). In 2009, 5,763 patients were treated with haemodialysis in the Czech Republic, while peritoneal dialysis was used in just 8% (458) of patients. This low number of peritoneal dialyses may be due to the still high number of chronic renal failure patients who come to dialysis centres "offthe street". Following acute initiation of haemodialysis, these patients are usually retained on haemodialysis. Poor awareness of peritoneal dialysis among patients as well as health care professionals is another reason for the low number of peritoneal dialysis patients. Peritoneal dialysis is suitable for home treatment. Peritoneum serves as the dialysis membrane, peritoneal cavity is filled with dialysis solution and the metabolism waste products and water are excreted into this solution. A base to correct metabolic acidosis then passes from dialysis solution into the body. Permanent catheter is inserted into the abdominal cavity to enable infusion of the dialysis solution. The dialysis is continual and this ensures stability of the inner environment and thus most closely resembles own kidney function. The advantages of peritoneal dialysis include longer preservation of residual renal function, inner environment stability and no need for venous access. Peritoneal dialysis is associated with a lower risk of infections. Peritoneal dialysis is contraindicated in patients after an extensive intraabdominal surgery and in patients with a stoma. Peritoneal damage is a serious complication of peritoneal dialysis; the risk increases with the treatment duration and thus peritoneal dialysis is not a long-term treatment choice. With the traditional CAPD (continual ambulatory peritoneal dialysis), the patient performs an exchange ofdialysis solution him/herself4 to 5 times a day. With APD (automated peritoneal dialysis) a machine performs dialysis solution exchanges, dialysis is performed at night and the patient may engage in other activities during a day. From the perspective of log-term survival of patients with chronic renal failure, peritoneal dialysis appears to be the method of choice. The patient is first treated with peritoneal dialysis and subsequently receives a transplant. Should the renal allograft be rejected, the patient returns to the dialysis programme, either peritoneal or haemodialysis. Patients should be provided with true and objective information about their disease and be informed about all treatment options for chronic renal failure. The choice of method has to be tailored to the overall health status of the patient as well as his/her lifestyle.