Breath analysis as promising indicator of hemodialysis efficiency.

BACKGROUND: The measurement of trimethylamine and isoprene in exhaled breath collected from dialysed patients indicates the changes in concentration of both compounds during dialysis. The aim of the presented study was to confirm diagnostic usefulness of TMA and isoprene detected in breath, as potential biomarkers of hemodialysis efficiency. METHODS: The samples of exhaled breath were collected from 22 dialyzed patients (9 women, 13 men) before and after hemodialysis (HD). All analyses were carried out using a gas chromatograph equipped with a mass spectrometer. Thermal desorption was used as breath sample enrichment method. RESULTS: Chromatographic analysis of breath samples indicated statistically significant differences in trimethylamine (TMA) and 2-methyl-1,3-butadiene (isoprene) concentrations in patients' breath collected before and after HD. TMA concentrations measured in breath samples, before dialysis, ranged from 0.024 to 0.461 nmol/L. After dialysis, the values of detected TMA were lower versus output values and ranged from 0.008 to 0.050 nmol/L. Isoprene concentrations before dialysis were present in the range from 0.236 to 9.718 nmol/L, after dialysis in the range from 0.478 to 26.182 nmol/L. Additionally, the dependences of TMA and isoprene concentrations, detected in breath with renal efficiency parameters detected in blood, were studied. The relationships between TMA and urea (r = 0.67; p < 0.00001) and creatinine (r = 0.61; p = 0.00002) were checked. In case of isoprene considerably higher concentrations were observed after dialysis, but no statistically significant correlation of isoprene with blood parameters was noticed. CONCLUSION: The observed decrease of TMA concentrations during dialysis could be useful as a measure of dialysis efficiency. The explanation of isoprene increase in breath during dialysis requires further investigation.

The application of chromatographic breath analysis in the search of volatile biomarkers of chronic kidney disease and coexisting type 2 diabetes mellitus.

Chromatographic studies on breath composition are aimed at finding volatile markers useful for medical diagnostics or in screening investigations. Studies leading to the development of screening breath tests are especially important for the diagnostics of chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). The aim of the presented study was to confirm diagnostic usefulness of chosen volatile compounds detected in breath, which are suggested as potential biomarkers of renal dysfunction and diabetes. Breath analysis were carried out in three groups: 10 healthy volunteers, 10 patients with CKD and 10 patients with CKD and T2DM. All exhaled air samples were analyzed using gas chromatograph (Agilent 6890GC) coupled with mass spectrometer (5975MSD). Thermal desorption was applied as the enrichment method. TMA was detected only in CKD patients. Higher breath concentrations of methanethiol (MeSH) were observed in CKD patients with coexisting diabetes than in patients with renal dysfunction only or in the healthy group. There was a tendency of increasing MeSH concentration in breath with increasing total glutathione in plasma (r=0.53, p=0.0026). Also, a trend of increasing dimethylsulfide (DMS) levels detected in breath was noticed with an increase of hydrogen sulfide concentration in plasma (r=0.74; p=0.00001) as well as with aspartate aminotransferase (AST), (r=0.61; p=0.001). The presented results suggest the possibility of applying TMA, MeSH, and DMS detection in breath as diagnostic methods.

Prognostic Value of Proinflammatory Markers in Patients After Kidney Transplantation in Relation to the Presence of Diabetes.

BACKGROUND: Patients who are receiving immunosuppressive treatment after kidney transplantation are at greater risk of developing new-onset diabetes after transplantation (NODAT). New biochemical markers that may contribute to a better assessment of the prognosis of renal failure for patients diagnosed with diabetes mellitus (DM) are needed. The aim of this study was to assess selected proinflammatory markers in patients after kidney transplantation depending on the prevalence of DM and to evaluate the predictive value of these cytokines. METHODS: A total of 82 patients were divided into 3 groups after kidney transplantation and were included in the analysis: group I, no DM; group II, DM diagnosed before transplantation; and group III, NODAT. Selected marker levels (platelet-derived growth factor, transforming growth factor ß1, tumor necrosis factor receptor II [TNF-RII], and high-sensitivity interleukin-6 [IL-6 HS]) were assessed by using enzyme-linked immunosorbent assays. For summary endpoint, a return to dialysis treatment and/or death of the patient was adopted. RESULTS: Patients with NODAT were characterized by higher levels of IL-6 HS and body mass index. There were no statistically significant differences in the levels of other assessed markers among the 3 analyzed groups. The summary endpoint was observed in 16 cases (19.5%). Patients with summary endpoint during the observation time at baseline had higher levels of TNF-RII (7180 vs 4632 pg/mL; P = .0002) and IL-6 HS (4.58 vs 2.72 pg/mL; P = .033). CONCLUSIONS: Levels of inflammatory markers in patients after kidney transplantation did not differ between groups with and without DM. In the study population, DM was not a significant risk factor for graft loss or death. Patients who experienced these complications at baseline were characterized by higher values of TNF-RII and IL-6 HS.