Experience and Utility of the Protocol Kidney Biopsy in the First Year of Kidney Transplantation.

BACKGROUND: Protocol kidney biopsy (PKB) in kidney transplant is a useful tool for graft monitoring because the subclinical detection of histologic lesions helps to modulate immunosuppression. We analyze our experience. METHODS: We performed a descriptive study that analyzed the PKB results at the fourth to sixth month and the first year post transplant of patients with kidney transplant followed in our hospital between January 2015 and June 2021. RESULTS: A total of 100 patients and 134 biopsy results were included, of which 71 were obtained between the fourth and sixth month and 63 at the first year. The mean age was 57.8 years, and 66% were men. Unknown etiology was the most common underlying kidney disease (31%), followed by diabetes mellitus (15%) and polycystic kidney disease (14%). A total of 80% had panel-reactive antibody < 50%. Induction therapy consisted of thymoglobulin (51%) and basiliximab (49%), and maintenance therapy consisted of corticosteroids and tacrolimus (100%), mycophenolate mofetil (82%), and mammalian target of rapamycin inhibitor (18%). Of the total of the PKB results (n = 134), 19 episodes of subclinical rejection (14%) and 10 with borderline changes (7.4%) were observed. Regarding other findings, there were cases of nephrocalcinosis (4.4%), immunoglobulin A nephropathy (2.2%), and BK nephropathy (1.5%). The PKB brought about a change in the therapeutic attitude in 45 cases (33%) of the total number of biopsies, the most frequent change being the administration of boluses of methylprednisolone (12.6%) and the change to mammalian target of rapamycin inhibitor (8.9%). CONCLUSIONS: In our experience, PKB is a useful tool for monitoring and evaluating histologic changes without clinical expression in the kidney graft, allowing us to adapt the treatment during the first year of kidney transplant.

Psychonephrology: psychological aspects in autosomal dominant polycystic kidney disease.

The biological, physical and psychological burden of a chronic disease has an impact on the quality of life of people who suffer from it. The perception of quality of life is affected by psychological disorders such as anxiety and depression that have a high prevalence in people with chronic kidney disease (CKD). These factors are also linked to lower life expectancy. It is therefore surprising that the psychological aspects of people with autosomal dominant polycystic kidney disease (ADPKD) have received so little attention in the medical literature, despite their importance for the overall health of these patients. The relatively new discipline called psychonephrology provides a broader view of the impact that these aspects have on individuals with chronic kidney disease, with a consequent practical application. In this article, we examine the consequences and prevalence of psychological problems that can be related to CKD and ADPKD. Firstly, we will focus on the field of CKD and ADPKD within the scope of psychonephrology. Secondly, the article introduces the concept of quality of life as a basic pillar of health that is affected when a person is diagnosed with CKD. Thirdly, we will present a summary of the main research related to anxiety and depression disorders in CKD and ADPKD. The article will conclude by synthesising findings from the different lines of research undertaken.

Diagnóstico molecular de la poliquistosis renal autosómica dominante en la Comunidad Autónoma de Canarias / Molecular diagnosis of adult dominant polycystic kidney disease in the Canary Islands

La poliquistosis renal autosómica dominante es una enfermedad hereditaria responsable del 6% de los casos de insuficiencia renal terminal en España. En la década de los 90 se identificaron los dos únicos genes relacionados con la enfermedad hasta el momento, en los cromosomas 16 y 4 (PKD1 y PKD2). El diagnóstico de esta enfermedad de desarrollo dependiente de la edad puede realizarse fácilmente mediante ecografía, pero el diagnóstico molecular mediante el análisis de ligamiento ofrece la ventaja de la detección precoz de individuos asintomáticos portadores del defecto genético, con vistas al seguimiento preventivo de estos individuos y al consejo genético. En este trabajo presentamos los resultados del análisis molecular de 30 familias con poliquistosis renal de la provincia de Las Palmas, realizado mediante análisis de ligamiento con dos series de marcadores polimórficos localizados en las inmediaciones de los genes PKD1 (D16S521, KG8, AC2.5, CW2, SM7) y PKD2 (D4S1538, D4S1534, D4S423, D4S414). Los objetivos del trabajo fueron: primero, comprobar el grado de informatividad y, por tanto, la utilidad de estos microsatélites para los estudios familiares de la PQRAD en nuestra población; y segundo, determinar la sensibilidad y especificidad del análisis genético en nuestra población. La mayoría de los marcadores mostró una alta heterocigosidad, comparable a la de otros estudios. Considerar los alelos de los distintos marcadores presentes en un mismo cromosoma conjuntamente, como un haplotipo, aumentó la informatividad de los marcadores y permitió la identificación inequívoca de los datos genéticos en el 97,7% de los pacientes y en el 88,7% de los individuos sanos. La sensibilidad y especificidad del análisis genético fueron del 90,7% (IC 95%: 85,7-95,7) y 86,8% (IC 95%: 80,6-93,0), respectivamente

Adult dominant polycystic kidney disease is an hereditary condition responsible for 6% of end-stage renal failure in Spain. Two genes were located in chromosomes 16 and 4 as related to this age-dependent disease in the 90s (PKD1 and PKD2). The diagnosis can be easily achieved by sonographic study, but molecular analysis by means of linkage analysis has the advantage of an early diagnosis in asymptomatic genetic carriers, with a view to the preventive follow-up of these subjects and genetic counselling. In this paper we present the results of molecular analysis of 30 families with Adult Dominant Polycystic Kidney Disease (from the province of Las Palmas Spain), carried out linkage analysis with two series of microsatellite markers located within or in the vicinity of PKD1 (D16S521, KG8, AC2.5, CW2, SM7) and PKD2 (D4S1538, D4S1534, D4S423, D4S414) genes. The objectives of the study were: first, to verify the informativeness, and therefore, the usefulness of these markers for family studies in our population; and second, to assess the sensitivity and specificity of the genetic analysis in our population. Most of the markers showed a high heterozigosity, comparable to data in other studies. Considering the alleles of the different markers together in a chromosome as an haplotype increased the informativeness of the markers, and allowed the unequivocal identification of genetic data in 97.7% of patients and 88.7% of healthy subjects. The sensitivity and specificity of the genetic analysis were 90.7% (CI 95%: 85.7-95.7) and 86.8% (CI 95%: 80.6- 93.0), respectively

[Molecular diagnosis of adult dominant polycystic kidney disease in the Canary Islands]. / Diagnóstico molecular de la Poliquistosis Renal Autosómica Dominante en la Comunidad Autónoma de Canarias.

Adult dominant polycystic kidney disease is an hereditary condition responsible for 6% of end-stage renal failure in Spain. Two genes were located in chromosomes 16 and 4 as related to this age-dependent disease in the 90s (PKD1 and PKD2). The diagnosis can be easily achieved by sonographic study, but molecular analysis by means of linkage analysis has the advantage of an early diagnosis in asymptomatic genetic carriers, with a view to the preventive follow-up of these subjects and genetic counselling. In this paper we present the results of molecular analysis of 30 families with Adult Dominant Polycystic Kidney Disease (from the province of Las Palmas Spain), carried out linkage analysis with two series of microsatellite markers located within or in the vicinity ofPKD1 (D16S521, KG8, AC2.5, CW2, SM7) and PKD2 (D4S1538, D4S1534, D4S423,D4S414) genes. The objectives of the study were: first, to verify the informativeness, and therefore, the usefulness of these markers for family studies in our population; and second,to assess the sensitivity and specificity of the genetic analysis in our population. Most of the markers showed a high heterozygosity, comparable to data in other studies. Considering the alleles of the different markers together in a chromosome as an haplotype increased the informativeness of the markers, and allowed the unequivocal identification of genetic data in 97.7% of patients and 88.7% of healthy subjects. The sensitivity and specificity of the genetic analysis were 90.7% (CI 95%: 85.7-95.7) and 86.8% (CI 95%: 80.6-93.0), respectively.

Diagnosis of iron deficiency in chronic renal failure.

The cause of anemia in chronic renal failure is multifactorial. Decreased erythropoietin (EPO) production is the main pathogenetic factor, but iron deficiency is the primary cause of unresponsiveness to EPO therapy. The diagnosis of iron deficiency in patients with chronic renal failure is difficult. We assessed the sensitivity and specificity of serum ferritin, total iron-binding capacity, transferrin saturation index, erythrocyte ferritin, and serum transferrin receptor in 63 patients with chronic renal failure undergoing dialysis (47 men, 16 women) with iron deficiency anemia. They were selected on the basis of clinical stability and absence of factors that may interfere with iron metabolism. None of the patients had received intravenous iron therapy or recombinant human erythropoietin (rHuEPO). Bone marrow biopsy with iron staining was the reference standard for iron stores. The receiver operating characteristic (ROC) curve and the area under the curve were calculated to assess the sensitivity and specificity of iron metabolism parameters. The parameter with the largest area under the ROC curve was serum ferritin (0.83). A cut point of 121 microgram/L showed a sensitivity and a specificity of 75%. The areas under the ROC curves of serum transferrin receptor and erythrocyte ferritin were 0.69 and 0.68, respectively. The remaining parameters showed areas under the ROC curve less than 0.65. Although serum transferrin receptor and erythrocyte ferritin may be acceptable markers for iron deficiency in stable chronic renal failure patients, serum ferritin level continues to be the most reliable diagnostic parameter. Transferrin saturation index is not a reliable parameter for the diagnosis of iron deficiency in stable patients not treated with rHuEPO.

Adequacy of dialysis in automated peritoneal dialysis: a clinical experience.

OBJECTIVES: To compare the peritoneal clearances of urea and creatinine in continuous ambulatory peritoneal dialysis (CAPD) with three types of automated peritoneal dialysis (APD): continuous cycling peritoneal dialysis (CCPD), 50% tidal peritoneal dialysis (TPD), and 25% TPD and to assess the usefulness of the peritoneal equilibration test (PET) in predicting peritoneal clearances in overnight APD. PATIENTS: Eleven uremic patients (mean age 44.5 +/- 15.45 years with a mean time on dialysis of 42.63 +/- 25.62 months) were included in the study. MEASUREMENTS: PET for urea and creatinine following Twardowski's method. Peritoneal clearances for urea and creatinine CAPD: samples of blood and dialysate within 24 hours. APD: blood mean levels of urea and creatinine before and after nighttime dialysis. Dialysate: urea and creatinine in nocturnal and daytime dialysate. RESULTS: Peritoneal clearance of creatinine was 38.14 +/- 9.99 L/week/1.73 m2 in CAPD, 44.28 +/- 12.4 L/week/1.73 m2 in CCPD, 50.07 +/- 17.86 L/week/1.73 m2 in 50% TPD (p < 0.05) and 40.18 +/- 6.65 L/week/1.73 m2 in 25% TPD. Peritoneal clearance of urea improved significantly in the three modalities of APD: 51.91 +/- 12.58 L/week/1.73 m2 in CAPD; 66.7 +/- 9.9 L/week/1.73 m2 in CCPD (p < 0.05); 76.3 +/- 14.5 L/week/1.73 m2 in 50% TPD (p < 0.001) and 64.4 +/- 11.4 L/week/1.73 m2 in 25% TPD (p < 0.05). The dialysate/ plasma (D/P) ratio of creatinine at 30, 60, 120, 180, and 240 minutes showed significant correlation with nighttime APD clearance. Nevertheless, only the D/P ratio of urea at 30, 60, and 120 minutes correlated with overnight APD clearance. CONCLUSIONS: A remarkable improvement was observed with APD regarding the clearance of urea mainly when 50% tidal peritoneal dialysis was used, whereas it was less noticeable in the clearance of creatinine. The PET is a helpful tool in predicting overnight peritoneal clearances of creatinine but it is less useful in predicting urea clearance.

[The long-term results on arterial pressure and kidney function after the percutaneous transluminal dilatation of renal artery stenosis]. / Resultados a largo plazo sobre la presión arterial y la función renal después de la dilatación transluminal percutánea de la estenosis de la arteria renal.

BACKGROUND: The purpose of this study was to evaluate the clinical results analyzing the cure, improvement and failure rates of percutaneous transluminal angioplasty (PTA) in patients with the diagnosis of renovascular hypertension with special reference to those with atherosclerotic vascular disease, according to their age, and their effect on blood pressure control and renal function. PATIENTS AND METHODS: In 93 hypertensive patients with a mean age of 43.4 years 123 renal artery PTA were performed: Twenty-six patients older than 50 years and eleven with 50 years or less had atherosclerosis, 27 fibromuscular dysplasia and a mixed disease was found in one patient. Twenty-eight patients with renal transplant were diagnosed as having arterial graft stenosis. RESULTS: After renal PTA, there was a significant decrease in blood pressure in all cases. Patients with atherosclerotic renal vascular disease showed a decrease in systolic pressure (SP) from 168 +/- 19 before PTA to 154 +/- 8 mmHg at 96 months (p < 0.001) and diastolic (DP) from 113 +/- 10 before PTA to 90 +/- 4 mmHg at 96 months (p < 0.001) respectively after the procedure. Significant differences were also observed in patients with fibromuscular dysplasia. Most patients with renal transplant arterial stenosis had less than five years of follow-up and SP and DP decreased from 162 +/- 18 and 109 +/- 8 mmHg before PTA, to 147 +/- 10 (p < 0.001) and 91 +/- 7 mmHg (p < 0.001) at 12 months after dilation respectively. Clinical improvement was achieved in 91% of patients with atherosclerosis at 96 months and fifty percent of the patients with fibromuscular dysplasia were cured after the same period from the time of PTA. Twelve months after the renal transplant artery dilation was achieved a clinical improvement in 81% and a cure rate in 6% of the patients. Ostial lesions comprised the majority of blood pressure benefit failures. There was no significant improvement in renal function immediately after renal artery dilation except in those patients with fibromuscular dysplasia. Residual stenosis greater than 75% was present in 15 patients after the first PTA. Complications were seen in 4.8% and were related to renal failure and vessel dissection. CONCLUSION: Angioplasty is effective in the long-term management of high arterial blood pressure and may preserve renal function according to renal artery disease.