The Importance of Natural and Acquired Immunity to SARS-CoV-2 Infection in Patients on Peritoneal Dialysis.

The pandemic caused by the SARS-CoV-2 virus had a great impact on the population of patients treated with peritoneal dialysis (PD). This study demonstrates the impact of infection and vaccination in 66 patients treated with PD and their outcomes during a 6-month follow-up. This is the first research that has studied the dynamics of anti-SARS-CoV-2 IgG in serum and effluent. In our research, 57.6% of PD patients were vaccinated, predominantly with Sinopharm (81.6%), which was also the most frequently administered vaccine in the Republic of Serbia at the beginning of immunization. During the monitoring period, the level of anti-SARS-CoV-2 IgG antibodies in the PD patients had an increasing trend in serum. In the group of vaccinated patients with PD, anti-SARS-CoV-2 IgG antibodies had an increasing trend in both serum and effluent, in contrast to non-vaccinated patients, where they decreased in effluent regardless of the trend of increase in serum, but statistical significance was not reached. In contrast to vaccinated (immunized) patients who did not acquire infection, the patients who only underwent the COVID-19 infection, but were not immunized, were more prone to reinfection upon the outbreak of a new viral strain, yet without severe clinical presentation and with no need for hospital treatment.

Significance of 1,25-Dihydroxyvitamin D3 on Overall Mortality in Peritoneal Dialysis Patients with COVID-19.

In previous publications, we pointed out the importance of mannosylation of fibrinogen for the development of cardiovascular complications and fucosylation as a predictor of peritoneal membrane dysfunction in patients on peritoneal dialysis (PD). After a follow-up period of 30 months from the onset of the COVID-19 pandemic, we evaluated the significance of 1,25-dihydroxyvitamin D3 (calcitriol) therapy, primary disease, biochemical and hematologic analyzes, and previously performed glycan analysis by lectin-based microarray as predictors of mortality in this patient group. After univariate Cox regression analysis, diabetes mellitus (DM) and calcitriol therapy were found to be potential predictors of mortality. Additional multivariate Cox regression analysis confirmed that only DM was a predictor of mortality. Nevertheless, the use of calcitriol in therapy significantly reduced mortality in this patient group, as shown by the Kaplan-Meier survival curve. The presence of DM as a concomitant disease proved to be a strong predictor of fatal outcome in PD patients infected with SARS-CoV-2. This is the first study to indicate the importance and beneficial effect of calcitriol therapy on survival in PD patients with COVID-19 infection. In addition, this study points to the possibility that adverse thrombogenic events observed in PD patients during the pandemic may be caused by aberrant fibrinogen glycosylation.

Increased Peritoneal Protein Loss and Diabetes: Is There a Link?

Increased peritoneal protein loss has been associated with the fast transport of small molecules, diabetes mellitus (DM), and a reduced survival in patients on peritoneal dialysis (PD), although some studies did not confirm the association with survival. In this single-center retrospective study, we investigated the relationship of baseline peritoneal albumin and protein loss with transport status, comorbidities including DM, and survival in 106 incident PD patients during the period of July 2005-June 2014. Five-year survival rate was determined using Cox-regression analysis. There were not significant differences in D/Pcr or peritoneal protein and albumin loss between diabetics and non-diabetics. In the group of 66 non-diabetics, high and high-average transporters for creatinine had higher values for both peritoneal protein (11.85 ± 6.77 vs. 7.85 ± 4.36 g/day; p = 0.002) and albumin (5.03 ± 2.32 vs. 3.72 ± 1.54 g/day; p = 0.016) loss as compared to slow transporters. However, in the group of 40 diabetics, this association was not observed. Upon multivariable regression analysis, the independent association of D/PCr with peritoneal albumin (ß = 0.313; p = 0.008) and protein (ß = 0.441; p = 0.001) loss was found only in non-diabetics in whom ultrafiltration also appeared as a significant predictor of peritoneal protein loss (ß = 0.330; p = 0.000). A high comorbidity grade, older age, and low serum albumin were associated with mortality, but both peritoneal protein and albumin loss as well as D/Pcr were not determinants of survival. Baseline peritoneal protein and albumin loss was not associated with DM and did not predict survival. The clinical significance of the absence of association between fast peritoneal transport status and peritoneal protein flux in diabetics should be evaluated in a prospective study comprising a greater number of diabetics with evaluation of overhydration as a main inducing variable of protein leak.

Otitis media with effusion as an initial manifestation of granulomatosis with polyangiitis.

Granulomatosis with polyangiitis is a systemic vasculitis of unknown etiology, characterized by necrotizing granulomas. It is an autoimmune disease affecting small- and medium-sized vessels of upper and lower respiratory tract, kidneys, and other organs. We described a case of a patient with otitis media with effusion as the first manifestations of granulomatosis with polyangiitis. A 54-year-old female presented as an urgent case with history of a severe otalgia, hearing loss, vertigo, and fever. The patient was treated with diagnosis of otitis media with effusion and acute rhinosinusitis, but without significant success. She developed an acute kidney dysfunction as a sign of glomerulonephritis with rapidly progressive renal failure. Diagnosis of granulomatosis with polyangiitis was confirmed after the histopathological analysis of kidney tissue, not by analysis of middle ear and paranasal sinus mucosa specimens. The patient was treated according to generally accepted protocol, and over time, there was an almost complete recovery.

[Evaluation of methods for rapid microalbuminuria screening in kidney diseased patients].

INTRODUCTION: One of the criteria for chronic kidney disease detection is determination of microalbuminuria. OBJECTIVE: This analysis was performed to evaluate accuracy of three useful methods for microalbuminuria detection in 24h urine collection and in the morning urine specimen calculated from urine albumin creatinine ratio, or with a dipstick in patients with different kidney diseases or kidney function. METHODS: Microalbuminuria was detected in 74 patients referred to the Outpatient Nephrology Department for kidney function determination or regular nephrology checking. Albumin concentration determined using immunonephelometry was lower than 300 mg/day. Discriminates cutoff values for spot urine test strip and albumin creatinin ratio in predicting 24 h protein'threshold' excretion were determined using ROC analysis. RESULTS: Mean value of 24 h microalbuminuria was 80.3 mg/24 h, and value >30 mg/24 h was present in 71.8% of patient. Correlation coefficients between dipstick microalbuminuria or albumin/creatinine ratio in a spot urine specimen and 24 h microalbuminuria were 0.709 and 0.598 (p<0.0001). For pathological value of 24 h microalbuminuria >30 mg/24 h, the coresponding dipstick microalbuminuria value was > or = 20 mg/L (AUC 0.849, specificity 95%, positive predictive value 97.3%), and > or = 3.55 mg albumin/mmol creatinine ratio (AUC 0.914, specificity 90% and positive predictive value 95.5%). No difference was found between dipstick mikroalbuminuria and albumin/creatinine ratio value. In addition, albumin/creatinine ratio value from 24 h urine was similar to the value obtained from the spot urine sample. CONCLUSION: Obtained results indicated that albuminuria could be determined accurately in spot urine either with the Micral test strip or with albumin creatinine ratio.

Early detection of chronic kidney disease: collaboration of Belgrade nephrologists and primary care physicians.

BACKGROUND: Belgrade screening study was undertaken in order to detect persons with CKD markers in at risk populations and to educate primary care physicians how to carry out CKD screening. METHODS: The study was performed by primary care physicians from thirteen Belgrade health centers in collaboration with nephrologists from clinical centers. Subjects without previously known kidney disease were enrolled: 1316 patients with hypertension without diabetes, 208 patients with type 2 diabetes and 93 subjects older than 60 years without hypertension or diabetes. The survey consisted of an interview, consisted of an interview, estimation of glomerular filtration rate (eGFR-MDRD), single urine dipstick detection of proteinuria, hematuria, glucosuria, microalbuminuria. RESULTS: Microalbuminuria with or without proteinuria in combination with eGFR>60 ml/min/1.73 m2 was detected in 17% , 41% and 24% of patients with hypertension, diabetes and those above 60 years, respectively. Reduced eGFR (<60 ml/min/1.73 m2 ) was found in 23%, 12% and 22% of the same patient groups. The prevalence of CKD markers increased with increasing number of risk factors. CONCLUSION: High prevalence of CKD markers in at risk population detected by primary care physicians in this collaborative study seems to be the best way to encourage primary care physicians to carry out regular CKD screening.

Early detection of chronic kidney disease: Collaboration of Belgrade nephrologists and primary care physicians

Background: Belgrade screening study was undertaken in order to detect persons with CKD markers in at risk populations and to educate primary care physicians how to carry out CKD screening. Methods: The study was performed by primary care physicians from thirteen Belgrade health centers in collaboration with nephrologists from clinical centers. Subjects without previously known kidney disease were enrolled: 1316 patients with hypertension without diabetes, 208 patients with type 2 diabetes and 93 subjects older than 60 years without hypertension or diabetes. The survey consisted of an interview, consisted of an interview, estimation of glomerular filtration rate (eGFR-MDRD), single urine dipstick detection of proteinuria, hematuria, glucosuria, microalbuminuria. Results: Microalbu minuria with or without proteinuria in combination with eGFR>60 ml/min/1.73m2 was detected in 17% , 41% and 24% of patients with hypertension, diabetes and those above 60 years, respectively. Reduced eGFR (<60 ml/min/1.73m2 ) was found in 23%, 12% and 22% of the same patient groups. The prevalence of CKD markers increased with increasing number of risk factors. Conclusion: High prevalence of CKD markers in at risk population detected by primary care physicians in this collaborative study seems to be the best way to encourage primary care physicians to carry out regular CKD screening (AU)

Antecedentes: El estudio de Belgrado se realizó para detectar personas con marcadores de ERC en poblaciones de riesgo y formar a los especialistas de atención primaria sobre cómo realizar proyecciones de ERC. Métodos: El estudio fue realizado por especialistas de atención primaria de trece centros de salud en colaboración con nefrólogos de centros clínicos. Se incluyó a personas sin enfermedad renal previa conocida: 1316 pacientes con hipertensión sin diabetes, 208 pacientes con diabetes tipo 2 y 93 pacientes de más de 60 años sin hipertensión ni diabetes. El estudio consistía en una entrevista, determinación de la tasa de filtración glomerular estimada (TFGe-MDRD) y detección de proteinuria, hematuria, glucosuria y microalbuminuria con una única tira reactiva de orina. Resultados: Se detectó microalbuminuria con o sin proteinuria en combinación con una TFGe >60 ml/min/1,73m2 en el 17%, el 41% y el 24% de los pacientes con hipertensión, diabetes y mayores de 60 años, respectivamente. Se encontró una TFGe reducida (<60 ml/min/1,73m2 ) en el 23%, el 12% y el 22% de estos mismos grupos de pacientes. La prevalencia de los marcadores de ERC aumentaba cuanto mayor era el número de factores de riesgo. Conclusión: La elevada prevalencia de marcadores de ERC en una población de riesgo detectada por los médicos de atención primaria en este estudio de colaboración parece ser la mejor forma de motivar a estos especialistas para que realicen cribados de ERC con regularidad (AU)

Screening of a population at risk of chronic kidney disease: analysis of factors associated with low eGFR and microalbuminuria.

BACKGROUND AND OBJECTIVE: Numerous screenings of chronic kidney disease (CKD) have been performed all over the world. This screening study was undertaken with the aim of estimating the prevalence of low glomerular filtration rate (eGFR) and microalbuminuria (MAU) and/or proteinuria in a population at risk for CKD and to detect factors associated with these CKD markers. MATERIALS AND METHODS: This cross-sectional study included 1617 patients without previously known kidney disease who came for regular check-ups to their general practitioners in 13 Belgrade health centers over a 3-month period. Patients selected were as follows: 1316 with hypertension, 208 with type 2 diabetes, and 93 older than 60 years without hypertension or diabetes. Screening included a questionnaire, blood pressure measurement, single MAU dipstick measurement (Micral-test® strip) and proteinuria and GFR estimation by Modification of Diet in Renal Disease. RESULTS: MAU was found in 419 (25.9%) patients, proteinuria in 163 (10.1%), and eGFR < 60 mL/min/1.73 m(2) in 370 (22.9%). Multivariate logistic regression analysis revealed that female gender, age, duration of hypertension, and smoking were associated with eGFR. Male gender, hypertension, treatment with angiotensin-converting enzyme inhibitors, proteinuria, and systolic blood pressure were associated with MAU. CONCLUSIONS: High prevalence of MAU/proteinuria and reduced eGFR were found in high-risk persons for CKD. Besides nonmodifiable, significant modifiable factors for MAU were use of angiotensin-converting enzyme inhibitors and strict regulation of hypertension and the factor for reduced eGFR was smoking.

Polyneuropathy in diabetic and nondiabetic patients on CAPD: is there an association with HRQOL?

BACKGROUND: It is well known that patients with uremia, as well as patients with diabetes mellitus, develop polyneuropathy. OBJECTIVES: The signs of polyneuropathy in diabetic and nondiabetic patients on continuous ambulatory peritoneal dialysis (CAPD) and their relation with age, duration of dialysis, biochemical parameters, dialysis adequacy, and health-related quality of life (HRQOL) were analyzed in the present study. PATIENTS AND METHODS: 65 CAPD patients (37 men, age 29-85 years, duration on dialysis 3 months to 14 years) were divided into two groups: group 1 was comprised of 20 diabetic patients (mean age 50.1+/-13.2 years); group 2 was comprised of 45 nondiabetic patients (mean age 62.3+/-9.7 years). Biochemical parameters, dialysis adequacy, and clinical signs were determined. Motor conduction velocity on the peroneal and tibial nerves and sensitive conduction velocity on the sural nerve were measured. The Kidney Disease Quality of Life Short Form (KDQOL-SF) was used to measure the CAPD patients' self-assessment of functioning and well-being using 4 component scores: physical component summary (PCS), mental component summary (MCS), kidney disease target issues, and patient satisfaction. RESULTS: Subjective symptoms were more intense in the diabetic patients and correlated with changes in peroneal and tibial distal motor latency (DML). Diabetic patients were significantly younger, had lower creatinine and higher glucose levels, and all analyzed pathological neurophysiological parameters were higher. Nondiabetic patients had prolonged latency of the F-wave on the peroneal nerve and the tibial nerve and reduced sensitive conduction velocity on the sural nerve. Significant correlations were found between the analyzed neurophysiological parameters and duration of dialysis and diabetes, glucose concentration, and dialysis adequacy in diabetic patients, and between neurophysiological parameters and age and dialysis adequacy in nondiabetic patients. Analysis of the 4 component scores of the KDQOL-SF revealed that diabetic patients had significantly better scores for PCS and MCS, which can be explained by their younger age. Patient satisfaction was worse in diabetic patients and correlated with duration of diabetes. In addition, significant correlations were established between PCS, MCS, and tibial DML (late neuropathic changes) in diabetic patients, and between MCS and tibial F-wave (early neuropathic changes) in nondiabetic patients. CONCLUSION: Polyneuropathy was significantly worse in diabetic than in nondiabetic patients on CAPD. DML on the tibial nerve correlated with glucose concentration, dialysis adequacy, PCS, and MCS in diabetic patients, whereas in nondiabetic patients, dialysis adequacy and azotemia correlated with F-waves on the peroneal nerve and the tibial nerve but MCS only with F-wave on the tibial nerve.

[Frequency of polyneuropathy signs in CAPD patients].

INTRODUCTION: It is well known that polyneuropathy has been an important cause of disability in patients maintained on hemodialysis as well as on peritoneal dialysis. The present study was aimed to analyze frequency and causes of polyneuropathy in patients on continuous ambulatory peritoneal dialysis (CAPD). MATERIAL AND METHODS: Sixty three CAPD patients (37 men), aged between 30 and 85 who were on dialysis from 1 to 290 months, were analyzed. Biochemical parameters and dialysis adequacy (KT/V) were determined. Motor conduction velocity (MCV) of peroneal and tibial nerve, and sensitive conduction velocity (SCV) on sural nerve were measured. RESULTS AND DISCUSSION: Biochemical parameters and dialysis adequacy were satisfactory in patients on CAPD. Polyneuropathy symptoms like paresthesias, pain, cramps and disability were found in more than 50% of patients. Over 80% of analyzed patients had pathological neurophysiological parameters: latency of F wave of n. peroneus and all analyzed parameters of n. tibialis, as the well as SCV on the sural nerve. A significant correlation was found between peroneal MCV and age, glycemia and serum creatinine; peroneal terminal latency (TL) and age; peroneal F wave and glycemia and serum urea; tibial MCV and glycemia; tibial F wave and glycemia, serum urea and KT/V. CONCLUSION: The most frequent signs of uremic polyneuropathy are reduced SCV on sural nerve and prolonged latency of F wave on peroneal and tibial nerves. Neurophysiological parameters on the lower extremities in patients on CAPD are in correlation with dialysis adequacy, glycemia and age.

[Hypertension in peritoneal dialysis patients].

INTRODUCTION: Continuous ambulatory peritoneal dialysis (CAPD) is effective in reducing blood pressure. Mean arterial pressure falls within 6 months of starting CAPD in the majority of patients. This improved blood pressure control reflects removal of excess fluid volume and body sodium. However, after several years, there is a decline in the efficacy of CAPD in controlling blood pressure. High incidence of hypertension in long-term CAPD patients may be related to hypervolemia as a consequence of loss of residual renal function (RRF), loss of ultrafiltration (UF) due to functional or structural changes in the peritoneal membrane, to a more liberated intake of sodium and fluid, or to administration of erythropoietin. The aim of the present study was to compare the efficacy in blood pressure contol in peritoneal dialysis patients depending on the dialysis modality and duration, RRF and dialysis adequacy. MATERIAL AND METHODS: This study was a retrospective analysis of 67 patients who attended our Clinic monthly in 2003. All patients received antihypertensive therapy (monotherapy - 16 pts, two drugs - 27 pts, three drugs - 22 pts and four - 2 pts.). RESULTS: The prevalence of hypertension (TA > 140/90 mmHg) was 73.13%. Most of them (50.75%) had mild hypertension (mean value TA <160/100 mmHg). There was no statistically significant difference in hypertension prevalence between diabetic (78.27%) and non-diabetic patients (75%). The prevalence of hypertension in patients with residual diuresis of more than 1000 ml was 36.6%, but there were 80.64% patients with residual diuresis less than 500 ml. A statistically significant negative correlation was found between D/D0, UF volume and systolic blood pressure and RRF, D/D0 and Ccr and diastolic blood pressure. A statistically significant positive correlation was found between age, body weight, duration of dialysis and systolic blood pressure and age and diastolic blood pressure. CONCLUSION: We can conclude that duration of PD treatment has a negative effect on blood pressure control. Residual renal function plays an important role in volume and blood pressure control. High and high average transporters are the two groups of patients at increased risk of developing hypertension, especially if they are anuric.