The relationship between uric acid levels and graft function in renal transplant patients who discontinued steroid therapy / Relación entre niveles de ácido úrico y función del injerto en pacientes de trasplante renal que interrumpieron la terapia con esteroides

ABSTRACT Introduction: High uric acid levels are commonly encountered in kidney transplant recipients, and can be associated with allograft dysfunction. Our study aims to examine the relationship between UA levels and graft function in patients discontinuing steroids. Methods: In this single-center-retrospective study, 56 patients discontinued steroid therapy from among 678 RT patients transplanted from living donors between 1999-2020 were included. The mean age of the study group was 45.8±8.8 years. Causes of steroid discontinuation, creatinine levels concurrent with uric acid levels before and after steroid discontinuation (mean 3.9 ± 2.1 years), acute rejection numbers, demographics, durations of dialysis and transplantation, medications, laboratory data, human leukocyte antigen (HLA) mismatch numbers, blood-pressure (BP), body mass index, delayed acute rejection (DAR) numbers (3 months post-transplantation) were all recorded. Results: Creatinine and uric acid levels were seen to have increased after steroid discontinuation, there was a significant relationship between them (p<0.001). Statistically significant correlation was found between increased creatinine levels after steroid discontinuation and graft survival with higher HLA mismatch; 39 (69.6%) patients with mismatch ≥2, and 17 patients with mismatch <2 (30.4%) (p=0.049) . No significant relationship was found between DAR numbers before and after steroid discontinuation, and creatinine levels after steroid discontinuation. Conclusion: Per model obtained as a result of multivariate linear analysis, hyperuricemia and HLA mismatch numbers (p= 0.048 and p= 0.044, respectively) are independent predictive factors for graft dysfunction in patients discontinuing steroids. Accordingly, negative effects of modeling should be kept in mind for long-term graft survival in patients who plan to continue with steroid-sparing regimens.

RESUMEN Introducción: Con frecuencia se registran niveles elevados de ácido úrico en receptores de trasplantes renales que pueden estar asociados a disfunción de aloinjerto. El presente estudio tiene por objeto examinar la relación entre los niveles de AU y la función del injerto en pacientes que interrumpieron la terapia con esteroides. Métodos: En este estudio retrospectivo en un solo centro participaron 56 pacientes con interrupción de la terapia con esteroides de un total de 678 pacientes con TR receptores de trasplante de donantes vivos en el período 1999-2020. La edad promedio de la población de estudio fue de 45,8 ± 8,8 años. En el estudio se registraron causas de la interrupción de la terapia con esteroides, niveles de creatinina concurrentes con niveles de ácido úrico antes y después de la interrupción de la terapia con esteroides (promedio de 3,9 ± 2,1 años), números de rechazo agudo, datos demográficos, duraciones del período de diálisis y trasplante, medicación (uso de inmunosupresores, antihipertensivos), datos de laboratorio, números de desajuste del antígeno leucocitario humano (HLA), presión arterial (PA), índice de masa corporal, números de rechazo agudo retardado (DAR) (3 meses después del trasplante). Resultados: Se observó que los niveles de creatinina y ácido úrico aumentaron tras interrumpir la administración de esteroides, con una relación significativa entre ambos (p<0,001). Se identificó una correlación estadísticamente significativa entre el aumento en los niveles de creatinina tras la interrupción de la terapia de esteroides y la supervivencia del injerto con un mayor desajuste de HLA: 39 pacientes (el 69,6%) con desajuste ≥2 y 17 (el 30,4%) pacientes con desajuste <2 (p=0,049). No se encontró una relación significativa entre el número de DAR antes y después de la interrupción del tratamiento con esteroides, así como en los niveles de creatinina tras la interrupción de la terapia con esteroides. Conclusión: De acuerdo con el modelo obtenido como resultado del análisis lineal multivariable, la hiperuricemia y los números de desajuste de HLA (p=0,048 y p=0,044, respectivamente) constituyen factores predictivos independientes para la disfunción del injerto en pacientes que interrumpen la terapia con esteroides. En consecuencia, se deben tener en cuenta los efectos negativos del modelado para la supervivencia del injerto a largo plazo en pacientes que planean proseguir con regímenes con reducción de la administración esteroides.

Impedance ratio: a novel marker and a powerful predictor of mortality in hemodialysis patients.

PURPOSE: Impedance ratio (Imp-R) obtained by multifrequency bioimpedance analysis (BIA) has been shown to be associated with volume and nutrition status. In this prospective study, the predictive role of Imp-R for mortality in hemodialysis (HD) patients was investigated. METHODS: Multifrequency (5-50-100-200 kHz) BIA was applied to 493 prevalent HD patients in March-April 2006. Imp-R was defined as the ratio of 200-5 kHz impedance values. Demographical, clinical and laboratory data at the time of the analysis were recorded. All-cause and cardiovascular (CV) mortality were assessed during 3 years of follow-up. RESULTS: Mean age was 57.7 ± 13.9 years, HD duration 52.1 ± 42.6 months and prevalence of diabetes 21.7 %. Imp-R was negatively correlated with nutritional markers including albumin, creatinine and hemoglobin levels. In addition, there was a positive correlation between Imp-R and age, ratio of extracellular water to total body water and high-sensitive C-reactive protein. Over a mean follow-up period of 27.9 ± 11.1 months, 93 deaths (52 from CV reasons) were observed. In the multivariate analysis, Imp-R was significantly associated with all-cause and CV mortality after adjustments [HR 1.13, 95 % CI (1.04-1.23); p = 0.004 and HR 1.15, 95 % CI (1.03-1.27); p = 0.01, respectively]. The risk of all-cause mortality was 3.4 times higher in the fourth quartile of Imp-R (>83.5 %) compared to the first Imp-R quartile (<78.8 %) as reference. Cutoff value of Imp-R for all-cause mortality was 82.0 % with a sensitivity of 65.5 % and specificity of 64 %. CONCLUSION: Impedance ratio measured by multifrequency in standardized conditions BIA is an independent and powerful predictor of both all-cause and CV mortality in hemodialysis patients.

Relationship of Interleukin-10 and Transforming Growth Factor-ß Levels With Short-Term Graft Function After Kidney Transplantation.

INTRODUCTION: We evaluated the relationship of interleukin-10 (IL-10) and transforming growth factor-ß (TGF-ß) levels with graft function in kidney transplantation patients receiving tacrolimus-based immunosuppression during the early post-transplantation period. MATERIAL AND METHODS: There were 112 patients who underwent kidney transplantation from live donors between May 2011 and May 2013. Eight patients had at least 1 of the exclusion criteria, and the remaining 104 patients were included in the study. The recipients underwent evaluation for biochemical markers, complete blood count, and creatinine and cytokine (IL-10, TGF-ß) levels during the pretransplantation and post-transplantation 6 months. RESULTS: The creatinine level was negatively correlated with IL-10 and positively correlated with TGF-ß levels in both the pretransplantation and early post-transplantation period. CONCLUSION: Low serum TGF-ß and high IL-10 levels at post-transplantation month 6 might have a positive effect on graft survival in living donor kidney recipients on tacrolimus-based immunosuppressive treatment.

Comparision of anti-HLA antibodies of kidney transplant candidates with chronic renal failure by two different methods: Flow-PRA and Luminex PRA.

OBJECTIVE: The aim of the study was to compare anti-HLA antibodies examined as panel-reactive antibody (PRA) in kidney transplant candidates with chronic renal failure (CRF) with the use of 2 methods: Flow-PRA and Luminex-PRA. METHODS: CRF patients displaying class I PRA (n = 34) and/or class II PRA (n = 41) were tested by the 2 different methods from April 2012 to September 2012, using antigen-coated beads. RESULTS: Eleven (32.3%) 34 patients tested for class I PRA were female and 23 (67.7%) male; 17 (41.5%) 41 patients tested for class II PRA were female and 24 (58.5%) male. Only 2 patients were preemptive, the others had been subjected to dialysis. The concordance ratio of class I PRA test results between Flow-PRA and Luminex PRA was 67.6%. Whereas 13 samples (38.2%) were positive by Flow-PRA, 22 (64.7%) were positive by Luminex-PRA. Two of the 3 patients not previously immunized were found to be positive only by Luminex PRA; 1 was noted to be positive only by Flow-PRA. Regarding class II PRA screening, the concordance between Flow-PRA and Luminex PRA was 70.7%. Whereas 14 (34.1%) samples were positive for Flow-PRA; 24 (58.5%) were positive for Luminex-PRA. The 2 patients not previously immunized were positive only in Luminex PRA. CONCLUSIONS: We speculated that the reason for the low concordance ratios was due to the use of sera that had been previously found to be indeterminate in PRA tests. We also speculated that the low concordance ratios were due to the coating procedure for the beads, which may cause changes in antigenic epitopes and decrease concordance between Flow-PRA and Luminex-PRA.