Waning Humoral Response 6 Month after Double Vaccination with the mRNA-BNT162b2 Vaccine in Hemodialysis Patients.

Introduction: Although most hemodialysis patients (HDP) exhibit an initial seroresponse to vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), studies have shown this response to be lower compared to healthy subjects. This fact raised concerns regarding the durability of the immune response and effective protection against severe Coronavirus disease 2019 (COVID-19) in this vulnerable population. The aim of our study was to evaluate the change in antibody levels over time in HDP population. Materials and Methods: We performed a prospective multicenter study, evaluating antibody response among HDP at 2 and at 6 months after complete two-dose vaccination course with the mRNA-BNT162b2 (Pfizer-BioNTech) vaccine. The study was performed in 14 hemodialysis units of a private dialysis provider in Lithuania. The serum samples of 189 HDP were tested for SARS-CoV-2 IgG against the Spike glycoprotein. Results: 189 HDP participated in the study. Patients were 64.3±15.7 years of age, 116 (61.4%) were males and 73 (38.6%) were females. Among them, 183 (96.8%) were seropositive for anti-S IgG at 2 months after the second immunization dose. Six months after the second dose only 145 (76.7%) of study participants had positive anti-S IgG titers. The median level of anti-S IgG titers after 2 months was 383.1 BAU/mL (166.2-995.6) and after 6 months this level significantly decreased to 51.4 BAU/mL (22.0-104.0) (p<0.001). Seroresponses at both time points inversely correlated with increasing patient's age. Risk factor for absent response after 2 months included oncologic disease. Systemic autoimmune disease and a history of myocardial infarction increased risk to be seronegative 6 months after the second vaccine dose. Conclusions: The majority of hemodialysis patients seroresponded after BNT162b2/Pfizer vaccination, but vaccine-induced humoral immunity wanes over time.

[Comparison of methods for evaluating renal function (Data of Kaunas University of Medicine Hospital in 2006)]. / Tyrimu, ivertinanciu inkstu funkcija, palyginimas (Kauno medicinos universiteto kliniku 2006 metu duomenys).

Cockcroft-Gault formula and Modification of Diet in Renal Disease (MDRD) equation are widely used as indirect estimates of renal function. The precision and reliability of these formulas regarding kidney function are still discussed. The aim of our study was to evaluate glomerular filtration rate by different methods and compare the results. Data on patients in whom renal function was evaluated at the Clinic of Nephrology of Kaunas University of Medicine Hospital in 2006 are presented in this article. Glomerular filtration rate was assessed based on 24-hour endogenous creatinine clearance and calculated using three formulas: Cockcroft-Gault, abbreviated MDRD, and complete MDRD. Blood serum creatinine level was measured by the standardized Jaffe assay. Glomerular filtration rate was examined in 125 patients. Their mean age was 58.07+/-18.962 years. The mean endogenous creatinine clearance was 31.1287+/-31.14 783 mL/min. The mean glomerular filtration rate calculated by Cockcroft-Gault formula was 34.1220+/-29.02 967 mL/min, by abbreviated MDRD formula was 29.8212+/-25.83 866 mL/min/1.73 m2, and by complete MDRD formula was 28.6884+/-24.99 353 mL/min/1.73 m2. There was no statistically significant difference in mean glomerular filtration rates estimated using all methods in the evaluation of kidney function. When the reliability of formulas was analyzed depending on each stage of chronic kidney disease, it was found that Cockcroft-Gault and MDRD formulas, in contrast to endogenous creatinine clearance, did not precisely reflect kidney function in stages 1 and 2 of chronic kidney disease. Estimates by Cockcroft-Gault and MDRD formulas correctly showed decreased kidney function in stages 3 and 4 of chronic kidney disease. Formulas were not reliable, in contrast to endogenous creatinine clearance, when patients were in end-stage chronic kidney disease. CONCLUSIONS. Cockcroft-Gault and MDRD formulas are best for the evaluation of moderate degree of renal insufficiency, and in early stage of chronic kidney disease, underestimation of glomerular filtration rate is possible by using formulas. Estimates of glomerular filtration rate based on formulas are higher as compared to endogenous creatinine clearance measurements in end-stage chronic kidney disease.

[Parallels in development of hemodialysis service and kidney transplantations in Lithuania during 1996-2005]. / Hemodializes tarnybos ir inkstu transplantacijos raidos paraleles Lietuvoje (1996-2005).

The aim of our study was to evaluate the changes in hemodialysis service, main demographic characteristics of hemodialysis patients in Lithuania during 1996-2005, and their correlation with the number of recipients on the kidney waiting list. During the study period, we annually visited all hemodialysis centers in Lithuania and collected data about all hemodialysis patients. There was a sharp increase in the number of hemodialysis centers (from 17 to 43), hemodialysis stations (from 25 to 100 per million population, P<0.001), hemodialysis patients (from 60 to 312 per million population, P<0.001), and new hemodialysis patients (from 54.3 to 95 per million population, P<0.01). The mean age of hemodialysis patients increased from 47.2+/-16.1 years in 1996 to 58.8+/-15.6 years in 2005 (P<0.001). Hemodialysis population became older. The percentage of patients aged more than 60 years increased from 22.8% to 53.2% (P<0.001) and aged more than 70 years from 5.4% to 24.4% (P<0.001). The frequency of chronic glomerulonephritis as underlying disease of end-stage renal disease decreased from 54.5% in 1996 to 21.1% in 2005 (P<0.001). There was an increase in the percentage of patients in whom end-stage renal disease was caused by diabetic (from 7.1% to 19.2%, P<0.01) and hypertensive nephropathies (from 3.1% to 13.9%, P<0.05) and chronic pyelonephritis (from 11.2% to 17.9%, P<0.01). The percentage of recipients on the kidney waiting list decreased from 71.4% in 1996 to 21.1% in 2005. In summary, during the last 9 years, hemodialysis service in Lithuania significantly expanded. The number of hemodialysis patients was continuously rising with predominance of diabetic, hypertensive, and elderly patients. Diabetic nephropathy, chronic glomerulonephritis, and pyelonephritis were the main underlying diseases of end-stage renal disease in hemodialysis patients in 2005. The percentage of recipients on the kidney waiting list decreased probably because of the rise in the number of elderly patients and patients with diabetes mellitus in Lithuanian hemodialysis population.

[Changes of control of disorders of calcium and phosphorus metabolism in Lithuanian hemodialysis centers 1996-2003]. / Kalcio ir fosforo apykaitos sutrikimu kontroles pokyciai Lietuvos hemodializes centruose 1996-2003 m.

The aim of the study was to evaluate the changes of the rate of disorders of calcium and phosphorus metabolism and their control in patients on hemodialysis (HD) in Lithuania in 1996-2003. Every December during this period we visited all HD centers of Lithuania and collected data on calcium-phosphorus metabolism in HD patients. 51.8% of HD patients in 1999 and 44.6% in 2003 had hyperphosphatemia (>1.8 mmol/l) (p<0.05). The mean phosphate concentration was 1.82+/-0.56 mmol/l in 2003 (p<0.05, comparing with 1.95+/-0.72 mmol/l in 1999 and 1.9+/-0.72 mmol/l in 2001). 7.1% of HD patients had hypocalcemia in 2003 and 7.8% hypercalcemia. Serum parathyroid hormone level was investigated only in 27.3% of HD patients in 1999 and 84.8% in 2003 (p<0.05). Use of alfacalcidol significantly decreased from 77.5% in 1998 to 29.4% in 2003, when the evaluation of serum parathyroid hormone increased (r=-0.911, p=0.03). Serum parathyroid hormone level was not analyzed for 59.8% of patients who used alfacalcidol and 59.4% of them had hyperphosphatemia in 1999 (6.3% and 32.9% in 2003, respectively; p<0.05). 10.7% of these patients had hypercalcemia in 2003. In summary, the correction of disorders of calcium and phosphorus metabolism in HD patients was insufficient but ameliorative. Monitoring of serum parathyroid hormone increased significantly during 1997-2003. The percentage of the precarious use of alfacalcidol decreased significantly when the evaluation of serum parathyroid hormone level became regular.