Immune responses of patients on maintenance hemodialysis after infection by SARS-CoV-2: a prospective observational cohort study

BACKGROUND

Immune dysregulation in patients with acute COVID-19 under chronic hemodialysis (CHD) is fully not elucidated. The changes of mononuclear counts and mediators before and after HD and associations with final outcome were studied.

METHOD

In this prospective study, hospitalized patients with moderate-to-severe COVID-19 under CHD and matched comparators under HD were analyzed for their absolute counts of lymphoid cells and circulating inflammatory mediators. Blood samples were collected before start and at the end of the first HD session; dialysate samples were also collected.

RESULT

Fifty-nine patients with acute COVID-19 under CHD and 20 uninfected comparators under CHD were enrolled. Circulating concentrations of tumor necrosis factor-alpha (TNFα), interleukin (IL)-10, interferon-γ and platelet-derived growth factor-A were increased in patients. Concentrations of mediators did not differ before and after HD. Significant decreases of CD4-lymphocytes and CD19-lymphocytes were found in patients. The decrease of the expression of HLA-DR on CD14-monocytes was associated with unfavorable outcome (defined as WHO-CPS 6 or more by day 28); increased counts of CD19-lymphocytes were associated with better outcomes.

CONCLUSION

Patients under CHD develop an inflammatory reaction to SARS-CoV-2 characterized by increase of inflammatory mediators, decrease of circulating T-lymphocytes and decrease of the expression of HLA-DR on CD14-monocytes.

MO627ASSOCIATION OF OXIDIZED LDL CHOLESTEROL WITH MORTALITY AND PROGRESSION OF PROTEINURIC DIABETIC KIDNEY DISEASE

Background and Aims

Oxidative modification of low-density lipoprotein (oxLDL) contributes to the pathogenesis and progression of oxidative stress (OS) and atherosclerosis in both Type 2 Diabetes Mellitus (T2DM) and Chronic Kidney Disease (CKD). Compared to normo-and micro-albuminuric, T2DM patients with macroalbuminuria have significantly higher plasma oxLDL levels. In this study we aimed to assess the possible predictive role of oxLDL for mortality and deterioration of renal function in a cohort of patients with proteinuric diabetic CKD.

Method

91 patients with diabetic retinopathy, persistent proteinuria and eGFR below 90ml/min were recruited. At baseline, oxLDL, proteinuria and eGFR were assessed and patients were categorized according to median oxLDL (above or below 66.22 U/L). All patients were prospectively followed for a period of 10 years or the occurrence of a combined outcome of mortality or at least 30% decline in eGFR and/or progression to end stage renal disease (ESRD), requiring renal replacement therapy. At the end of the follow-up period, renal function was re-assessed with a new estimation of eGFR, using the CKD-EPI formula. We performed a statistical analysis with receiver operation curves (ROC) to further examine the possible effect of oxLDL on the percentage change in eGFR and proteinuria over time (calculated as ΔeGFR/baseline eGFR and Δproteinuria/baseline proteinuria respectively) and divided by the follow-up time.

Results

The mean age of the patients was 67.02±8.2 years, and the mean duration of T2DM was 14.5±8.0 years. At baseline, compared to the low, patients with high circulating oxLDL levels had significantly higher levels of triglycerides, higher diastolic blood pressure and lower eGFR (P=0.001, P=0.04 and P-0.013, respectively, Mann-Whitney test). After a 10-year follow up, 10/46 patients in the low and 20/45 patients in the high ox-LDL group presented the composite outcome. Kaplan-Meier curves (Figure 1) showed that patients with oxLDL levels above median (>66.22 U/L) presented a significantly higher risk for the outcome compared to the low oxLDL group (P=0.001, log-rank test). Univariate Cox proportional hazard analysis revealed that high circulating oxLDL levels were independent predictors of the composite endpoint (HR=3.42, 95%CI: 1.55-7.56, P=0.002). After adjustment for all factors that were associated with the outcome in univariate models (baseline proteinuria, serum albumin, duration of T2DM and triglycerides), multivariate Cox analysis showed that the association between high oxLDL levels and the study endpoint remained significant (HR=3.76, 95%CI: 1.52-9.27, P=0.004). At ROC analysis the area under the curve (AUC) for oxLDL to identifying progressor patients was 0.68 (95% CI: 0.56-0.80, P=0.005). Of note, this AUC was virtually identical to that of baseline proteinuria. OxLDL failed to show any association with the change of proteinuria over time.

Conclusion

Circulating ox-LDL might play an important role in the progression of proteinuric DKD.

Age dependence of brachial cuff-based ambulatory PWV in end-stage kidney disease patients undergoing long-term peritoneal dialysis

BACKGROUND

The newly introduced device Mobil-O-Graph (IEM, Stolberg, Germany) combines brachial cuff oscillometry and pulse wave analysis, enabling the determination of pulse wave velocity (PWV) via complex mathematic algorithms during 24-h ambulatory blood pressure monitoring (ABPM). However, the determinants of oscillometric PWV in the end-stage kidney disease (ESKD) population remain poorly understood.

METHODS

In this study, 81 ESKD patients undergoing long-term peritoneal dialysis underwent 24-h ABPM with the Mobil-O-Graph device. The association of 24-h oscillometric PWV with several demographic, clinical and haemodynamic parameters was explored using linear regression analysis.

RESULTS

In univariate analysis, among 21 risk factors, 24-h PWV exhibited a positive relationship with age, body mass index, overhydration assessed via bioimpedance spectroscopy, diabetic status, history of dyslipidaemia and coronary heart disease, and it had a negative relationship with female sex and 24-h heart rate. In stepwise multivariate analysis, age (β: 0.883), 24-h systolic blood pressure (BP) (β: 0.217) and 24-h heart rate (β: -0.083) were the only three factors that remained as independent determinants of 24-h PWV (adjusted R ² = 0.929). These associations were not modified when all 21 risk factors were analysed conjointly or when the model included only variables shown to be significant in univariate comparisons.

CONCLUSION

The present study shows that age together with simultaneously assessed oscillometric BP and heart rate are the major determinants of Mobil-O-Graph-derived PWV, explaining >90% of the total variation of this marker. This age dependence of oscillometric PWV limits the validity of this marker to detect the premature vascular ageing, a unique characteristic of vascular remodelling in ESKD.

P1014INCRETIN BASED THERAPIES IN DIABETIC KIDNEY TRANSPLANT RECIPIENTS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background and Aims

Diabetes mellitus (DM) is the major cause of ESRD. New-onset DM after transplantation (NODAT) frequently occurs and increases the risk of infection and mortality. Kidney transplant recipients (KTR) with pre-existing risk factors for DMt2 are more prone to develop NODAT. An intriguing novel concept is the use of the incretin-based therapies including dipeptidyl peptidase-4 inhibitors (DPP-4i), glucagon-like peptide-1 receptor agonists (GLP-1-RAs) and Sodium-glucose co-transporter-2 inhibitors (SGLT2i) in solid organ transplantation. This class of antidiabetic therapy is not yet established in KTR. Our aim was to examine the efficacy and safety of incretin-based therapies in DM or NODAT in KTR.

Method

We searched without language restrictions for all publications on Kidney/Renal Transplantation and DPP-4i, GLP-1-RAs and SGLT-2i using electronic databases including Medline, Embase, Cochrane, PubMed. We hand-search the reference lists of every relevant study for additional publications. Further searches were done by reviewing abstract and review articles. We included every study (retrospective/prospective) that used these classes of antidiabetics as treatment of NODAT or DMt2 in KTR. All the primary and secondary outcomes were calculated as mean ± sd. Heterogeneity was assessed with Cochrane’s Q statistics and quantified using the I stat, which indicated the proportion of variability across studies that was due to heterogeneity. We used the DerSimonian-Laird estimator for tau^2. Meta-regression was used to assess the effect of different antidiabetics on the primary and secondary outcomes. We assumed a priori the presence of heterogeneity and we used the model of random effects in all analyses. We assessed publication bias using the Begg-Mazumdar test and to nullify the estimated bias the trim-and-fill method, where it was necessary. A p-value < 0.05 was considered statistical significant.

Results

On the 1512 references screened, 16 studies were included in the final analysis. In total, 310 individuals were analyzed with a mean age of 55.98 ± 8.81 years, similar between studies. In 10 of them, participants were diagnosed with NODAT, whereas in all other trials were DMt2 or NODAT. In 8 studies participants received DPP-4i, in 6 SGLT-2i i and in rest 2 GLP-1-RAs. All included KTR were stable and transplanted over 6 months. The mean follow-up of all trials included was 22,03±14.95 weeks. Glycemic control reduces HbA1c (10 studies, MD=-0.38 %, I=45%). The MD of HbA1c for the DPP-4i group was -0.3741 and for the SGLT-2i group was -0.4596 mg/dl. Within every group of each different category of drugs, there was homogeneity (QM, p-value>0.05) and it was explained the most of the variance of the previous meta-analysis (QE= 15.76). The Begg-Mazumdar test showed that publication bias was not present (p> 0.05). Nine trials reported the difference of FPG and 5 of PPG before and after the administration of antidiabetics. The common MD estimator with a random effect model was – 25.76 for FPG and – 6.61 for PPG with a high grade of heterogeneity for both. Seven trials reported the change of body mass index (BMI) and body weight (BW) before and after the administration of this class of antidiabetics. The BW reduction, where reported, was significant in KTR on SGLT1i or DPP-4i whereas BMI wasn’t significantly reduced in this group, possible due to statistical artifact. The majority of the studies showed that GFR and hepatic biochemical parameters, didn’t change during therapy (DPP-4i, GLP-1-RAs, SGLT-2i).

Conclusion

Evidence concerning the efficacy of incretins in diabetes on KTR is limited. SGLT2i and DPP-4i are efficacious for glucose-lowering. The safety profile based on renal and hepatic function is indicative for the use of this class of antidiabetics in this population. More high-quality studies are required to help guide therapeutic choice for antidiabetics in KTR.

Evaluation of a novel brachial cuff-based oscillometric method for estimating central systolic pressure in hemodialysis patients

BACKGROUND/AIMS

Elevated wave reflections and arterial stiffness, as well as ambulatory blood pressure (BP) are independent predictors of cardiovascular risk in end-stage-renal-disease. This study is the first to evaluate in hemodialysis patients the validity of a new ambulatory oscillometric device (Mobil-O-Graph, IEM, Germany), which estimates aortic BP, augmentation index (AIx) and pulse wave velocity (PWV).

METHODS

Aortic SBP (aSBP), heart rate-adjusted AIx (AIx(75)) and PWV measured with Mobil-O-Graph were compared with the values from the most widely used tonometric device (Sphygmocor, ArtCor, Australia) in 73 hemodialysis patients. Measurements were made in a randomized order after 10 min of rest in the supine position at least 30 min before a dialysis session. Brachial BP (mercury sphygmomanometer) was used for the calibration of Sphygmocor's waveform.

RESULTS

Sphygmocor-derived aSBP and AIx(75) did not differ from the relevant Mobil-O-Graph measurements (aSBP: 136.3 ± 19.6 vs. 133.5 ± 19.3 mm Hg, p = 0.068; AIx(75): 28.4 ± 9.3 vs. 30.0 ± 11.8%, p = 0.229). The small difference in aSBP is perhaps explained by a relevant difference in brachial SBP used for calibration (146.9 ± 20.4 vs. 145.2 ± 19.9 mm Hg, p = 0.341). Sphygmocor PWV was higher than Mobil-O-Graph PWV (10.3 ± 3.4 vs. 9.5 ± 2.1 m/s, p < 0.01). All 3 parameters estimated by Mobil-O-Graph showed highly significant (p < 0.001) correlations with the relevant measurements of Sphygmocor (aSBP, r = 0.770; AIx(75), r = 0.400; PWV, r = 0.739). The Bland-Altman Plots for aSBP and AIx(75) showed acceptable agreement between the two devices and no evidence of systemic bias for PWV.

CONCLUSION

As in other populations, acceptable agreement between Mobil-O-Graph and Sphygmocor was evident for aSBP and AIx(75) in hemodialysis patients; PWV was slightly underestimated by Mobil-O-Graph.

Daptomycin determination by liquid chromatography-mass spectrometry in peritoneal fluid, blood plasma, and urine of clinical patients receiving peritoneal dialysis treatment

A 13-min LC-MS method was developed for the determination of daptomycin, a new potent antibiotic, in peritoneal fluid, blood plasma, and urine of patients receiving renal replacement therapy. Chromatography was performed on a C(18) column and detection was performed by a single-quadrupole mass spectrometer coupled to LC via an electrospray interface (ESI). The column effluent was also monitored at 370 nm using a photodiode-array detector. The developed method provided a linear dynamic range for concentrations from 0.5 microg mL(-1) to 100 microg mL(-1). Method precision and accuracy were found to be satisfactory for clinical application, thus the method was successfully used for the analysis of daptomycin in pharmacokinetic studies. The drug was preventively administered against Gram-positive infections to 19 clinical patients undergoing peritoneal dialysis. Peritoneal fluid, blood plasma, and urine samples were collected at 13 time points over a period of 48 h. Clinical samples were analysed following simple sample-preparation procedures and daptomycin was unambiguously detected and quantified.