A decrease in the incidence of Shiga toxin-related hemolytic uremic syndrome as a cause of kidney transplantation at an argentine referral center.

BACKGROUND: In Argentina, Hemolytic uremic syndrome caused by Shiga toxin-producing Escherichia coli (STEC HUS), is the main cause of acute kidney injury and the second cause of end-stage renal disease (ESRD) in children. In recent decades, strategies have been implemented to reduce progression to ESRD, but it is not known whether the cumulative incidence of HUS requiring kidney transplantation (KTx) has decreased. We aimed to determine whether the cumulative incidence of STEC HUS in children undergoing KTx decreased and compared outcomes of HUS-related KTx vs. those related to other etiologies. METHODS: All patients who underwent KTx at our institution were evaluated. The cohort was divided into quintiles (Q), and we compared the cumulative incidence of HUS-related KTx vs KTx due to other etiologies. RESULTS: A total of 1000 consecutive KTx were included. The cumulative incidence of HUS-related KTx was 11%. HUS was the second cause of KTx in Q1: 17% (1988-1995); Q2: 13.5% (1996-2003); Q3: 11.5% (2004-2009) and third cause in Q4: 10% (2010-2015) and Q5: 3% (2016-2021). The cumulative incidence of HUS-related KTx decreased in Q4 and Q5 compared to Q1, Q2, and Q3 and the decline was even steeper when comparing Q4 to Q5 (p:0.019). There was no difference in graft survival in patients with HUS vs. congenital anomalies of kidney and urinary tract (CAKUT) but better than in those with focal segmental glomerulosclerosis (FSGS). CONCLUSIONS: In this cohort, the cumulative incidence of HUS-related KTx decreased, which may have been due to the implementation of nephroprotective strategies.

Nephro-urological outcomes of a proactive management of children with spina bifida in their first 5 Years of life.

INTRODUCTION: The proactive management of spina bifida (SB), especially of its severe form, myelomeningocele (MMC), has contributed to decreasing chronic kidney disease (CKD). The objective of this study is to present the evolution of 5-year-old patient with MMC followed from birth with a proactive approach. MATERIAL AND METHODS: This retrospective study included 55 cases with MMC of up to 5 years of age. All of them were admitted at birth and followed by a multidisciplinary group, with a proactive approach: CIC and anticholinergics. In the same group, the variables were compared within the first year and the within the fifth year of life. Chronic kidney disease (CKD) was defined by: alterations on renal DMSA scintigraphy; alterations in microalbuminuria/creatininuria ratio, proteinuria 24 hs and decrease in glomerular filtration rate (GFR) calculated with Schwartz bedside equation. RESULTS: Although overactivity, UTI and VUR decreased throughout the first 5 years (49, 9 and 12%), reduced cystometric capacity, DLPP >40 cm of water and end-filling pressure (Pdet) >20 cm of water increased (41, 27 and 61%). All patients at 5 years of age required CIC. Reduced cystometric capacity and VUR were more significant with abnormal DMSA (36%) at 5 years old ( p: 0.03). Proteinuria and CKD increased to 25% and 49%. Similarly, the need for enalapril increased from 10% to 27%. The microalbuminuria/creatininuria ratio was pathological in 27.3%. 48 patients (87%) remained unchanged on DMSA scan and the other 7 underwent modifications (4 new cases with altered DMSA) over time. Of the 32 normal DMSA cases without changes, 81% did not present proteinuria and 88% continued to respond favorably to oxybutynin. GFR <90 ml/min/1.72m 2 was found in only 3 cases with abnormal DMSA. There was a RR 1.91 (IC95% 1.15-3.16) greater of renal compromise in cases that were anticholinergic-resistant compared to non-refractory cases. DISCUSSION: Over time, some patients suffered loss of bladder wall compliance, despite the proactive approach. There is an association between abnormal renal DMSA, reduced bladder capacity, and VUR at 5 years of age. Although proteinuria, CKD and enalapril requirement increased over 5 years, almost 90% did not show changes in renal DMSA status. CONCLUSIONS: Over time, some patients suffered loss of bladder wall compliance. Hence, even if a proactive approach is followed since birth, it is essential to continue with the ongoing monitoring of the renal status and thus avoid greater renal deterioration.

"Epstein-Barr virus associated smooth muscle tumour as an unusual cause of ureteric graft obstruction in a child".

BACKGROUND: Epstein-Barr virus (EBV) is a DNA virus with oncogenic potential, especially in immunocompromised patients. EBV can promote smooth muscle proliferation, resulting in EBV-associated smooth muscle tumors (EBV-SMT). METHODS: We report a case of a 10-year-old child with end-stage renal disease secondary to hypoplastic crossed and fused kidneys who underwent kidney transplantation. EBV serology was unknown for the donor and negative for the recipient; three months after he had a primary EBV infection. Two years after the transplantation, percutaneous nephrostomy was performed because of a drop in the estimated glomerular filtration rate and severe dilatation of the graft. Nephrography showed contrast enhancement of the pelvis of the graft kidney and proximal ureter, with a clear blockage at the level of the mid ureter and no passage towards the bladder. A 1.5-cm tumor was found causing intraluminal compression of the mid ureter. RESULTS: Complete resection of the tumor and distal ureter was performed leaving a short proximal ureter. A tension-free uretero-ureteroanastomoses was achieved using the native ureter. There were no surgical complications. Histologic evaluation showed spindle-shaped muscle cells, moderate pleomorphism, and inflammatory infiltration. Immunohistochemical staining was positive for muscle-specific actin. Epstein-Barr encoding region (EBER) in situ hybridization was positive, confirming the diagnosis of EBV-associated SMT. CONCLUSIONS: EBV-SMT is an exceedingly rare oncological entity that may develop in either the graft or any other organ. The clinical findings are location related. EBV seroconversion following transplantation might be a risk factor for the development of SMT in solid organ recipients.

Hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli infection in Argentina: update of serotypes and genotypes and their relationship with severity of the disease.

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) infection is the most common cause of hemolytic uremic syndrome (HUS). Only few studies correlated serotypes and stx genotypes with disease severity. This study aimed to update STEC serotypes, stx genotypes, and virulence factors (eae and ehxA) in a cohort of patients with STEC-HUS and investigate whether they influence the severity of disease. METHODS: In this multicentric study, children hospitalized between 2005 and 2016 with STEC-HUS confirmed by the National Reference Laboratory were included. Serotypes (O157, O145, O121, and others), stx genotypes (stx1a, stx2a, stx2c, stx2d, and others), and virulence factors were analyzed, and their association with dialysis requirement (>10 days); severe neurological, cardiovascular, and/or bowel involvement; and death was assessed. RESULTS: The records of 280 patients were reviewed; 160 females, median age 21 months (IQR18m). STEC O157 was isolated in 206 (73.6%) patients, O145 in 47 (16.8%), O121 in 15 (5.4%), and other serotypes in 12 (4.2%). The stx2a/2c genotype was carried by 179 (63.9%) strains, stx2a by 94 (33.6%), stx1a/stx2a by five (1.8%), and stx1a only by two (0.7%). All strains except six harbored eae and ehxA genes. Fifty-nine (21.1%) patients had severe neurological involvement, 29 (10.4%) severe bowel injury, 14 (5%) cardiovascular involvement, 53 (18.9%) required > 10 days of dialysis, and 12 (4.3%) died. Neither serotypes nor stx genotypes detected were significantly linked to severity. CONCLUSIONS: Serotype O157 and virulence stx2a/2c, eae, ehxA genotype are prevalent in Argentina, and no relationship was found between severity and serotypes and genotypes of STEC detected.

Intensive Safety Monitoring of Rituximab (Biosimilar Novex® and the Innovator) in Pediatric Patients With Complex Diseases.

Although rituximab is widely used off-label for complex pediatric diseases, safety reports are limited. We aimed to report evidence of its use in clinical practice, to describe the incidence of adverse drug reactions (ADR) to rituximab biosimilar Novex® and innovator, and to identify risk factors for the development of ADR in a real-life follow-up cohort of pediatric patients with complex diseases. We conducted a prospective, longitudinal, observational, single-centre study in patients that received rituximab for any complex disease, and as part of an intensive pharmacovigilance program. Demographic, pharmacological, clinical, and drug-related data were collected for all patients. ADR-free survival, including infusion-related reactions (IRR) and delayed ADR (dADR), was estimated using Kaplan-Meier curves. Risk factors were evaluated by multivariable Cox regression models. In total, 77 patients (<19 y.o.) received 187 infusions of rituximab Novex® (n = 155) or innovator rituximab (n = 32) for neurologic (Neu), immune-hematologic-rheumatic (IHR), oncologic (O) diseases, and hematopoietic stem-cell transplantation (HSCT) or solid-organ transplantation (SOT). We recorded 29 IRR and 58 dADR that occurred in 27 (35.1%) and 29 (37.7%) patients, respectively. The respiratory tract was the most affected during IRR (29.6%) and hypogammaglobulinemia (37.9 %) was the most frequent dADR. First versus subsequent infusions (HR 5.4, CI95% 2.4-12.1, p<0.05), sex (boys vs. girls, HR 0.3, CI95% 0.1-0.8, and p<0.05), and diagnosis (Neu-IHR diseases vs. O-HSCT-SOT, HR 2.3, CI95% 1.02-5.4, and p < 0.05) were significantly associated with the development of IRR. For dADR, risk factors were diagnosis (Neu-IHR diseases vs. O-HSCT-SOT, HR 0.4, CI95% 0.2-0.9, and p < 0.05) and cumulative body surface area-normalized dosage (HR 1.0003, CI95% 1.0001-1.0006, and p < 0.05). The present is the largest real-world safety assessment of rituximab in Latin-American children with complex diseases supporting its use based on the overall acceptable safety. Identification of risk factors may contribute to optimization of off-label rituximab treatment in pediatrics.

Kidney transplantation in children with CAKUT and non-CAKUT causes of chronic kidney disease: Do they have the same outcomes?

Almost half the children who undergo kidney transplantation (KTx) have congenital abnormalities of the kidney and urinary tract (CAKUT). We compared patient, graft survival, and kidney function at last follow-up between CAKUT and non-CAKUT patients after KTx. We divided the analysis into two eras: 1988-2000 and 2001-2019. Of 923 patients, 52% had CAKUT and 48% non-CAKUT chronic kidney disease (CKD). Of the latter, 341 (77%) had glomerular disease, most frequently typical HUS (32%) and primary FSGS (27%); 102 had non-glomerular disease. CAKUT patients were more often boys, younger at KTx, transplanted more frequently preemptively, but with longer time on chronic dialysis. They had less delayed graft function (DGF) and better eGFR, but higher incidence of urinary tract infection (1 year post-KTx). In both eras, 1-, 5-, and 10-year patient survival was similar in the groups, but graft survival was better in CAKUT recipients vs those with primary glomerular and primary recurrent glomerular disease: Era 1, 92.3%, 80.7%, and 63.6% vs 86.9%, 70.6%, and 49.5% (P = .02), and 76.7%, 56.6%, and 34% (P = .0003); Era 2, 96.2%, 88%, and 73.5% vs 90.3%, 76.1%, and 61% (P = .0075) and 75.4%, 54%, and 25.2% (P < .0001), respectively. Main predictors of graft loss were DGF, late acute rejection (AR), and age at KTx in CAKUT group and disease relapse, DGF, early AR, and number of HLA mismatches in recipients with glomerular disease. Graft survival was better in CAKUT patients. DGF was the main predictor of graft loss in all groups. Disease recurrence and early AR predicted graft failure in patients with glomerular disease.

Series de Pediatría Garrahan. El niño con trastornos renales y de las vías urinarias / Garrahan Pediatrics Series. The child with renal and urinary tract disorders

Las consultas pediátricas por enfermedad renal o de las vías urinarias son frecuentes e incluyen una amplia variedad diagnóstica que desafía al pediatra en su abordaje, la detección de riesgos en el corto y largo plazo, la derivación oportuna al especialista y el seguimiento de las condiciones que generaron cronicidad. En este nuevo volumen de las Series de Pediatría Garrahan se han reunido prestigiosos pediatras y nefrólogos infantiles para actualizar y trasnmitir el manejo integral de algunas de las patologías de mayor prevalencia e impacto, muchas de las cuales causan morbilidad alejada y requieren equipos multidisciplinarios que aseguren una transición en el cuidado del niño, el adolescente y el adulto. Entre sus caracterísitcas se destacan: El estudio detallado de patologías clínicas como las infecciones urinarias, la lesión renal aguda, el síndrome nefrótico, la enfermedad renal progresiva, las terapias de reemplazo renal y la hypertensión arterial. El desarrollo de casos clínicos con las secuencias habituales en el transcurso habitual de las enfermedades que permite destacar las presentaciones clínicas, las alternativas diagnósticas y terapéuticas, así como las posibilidades evolutivas. El cierre de cada capítulo con un recordatorio de puntos clave y lecturas recomendadas y, además, el material complementario disponible en el sitio web. El objetivo es compartir la modalidad de trabajo del hospital, con base en el rol central del pediatra como coordinador de la atención interdisciplinaria en cada una de sus etapas. Una obra actualizada y práctica que aporta información científica y experiencia de los profesionales de una institución de prestigio, de granutilidad para todos aquellos miembros del equipo de salud que atienden y cuidan niños, dondequiera que trabajen al servivio de la salud infantil.

Hyponatremia: a new predictor of mortality in patients with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome.

OBJECTIVES: (1) Evaluate mortality rate in patients with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome, (2) determine the leading causes of death, and (3) identify predictors of mortality at hospital admission. METHODS: We conducted a multicentric, observational, retrospective, cross-sectional study. It included patients under 18 years old with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome hospitalized between January 2005 and June 2016. Clinical and laboratory data were obtained from the Argentine National Epidemiological Surveillance System of Hemolytic Uremic Syndrome. Clinical and laboratory variables were compared between deceased and non-deceased patients. Univariate and multivariate analyses were performed. ROC curves and area under the curve were obtained. RESULTS: Seventeen (3.65%) out of the 466 patients died, being central nervous system involvement the main cause of death. Predictors of death were central nervous system involvement, the number of days since the beginning of diarrhea to hospitalization, hyponatremia, high hemoglobin, high leukocyte counts, and low bicarbonate concentration on admission. In the multivariate analysis, central nervous system involvement, sodium concentration, and hemoglobin were independent predictors. The best cut off for sodium was ≤ 128 meq/l and for hemoglobin ≥ 10.8 g/dl. CONCLUSIONS: Mortality was low in children with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome, being central nervous system involvement the main cause of death. The best mortality predictors found were central nervous system involvement, hemoglobin, and sodium concentration. Hyponatremia may be a new Shiga toxin-producing Escherichia coli hemolytic uremic syndrome mortality predictor.

Near-adult height in male kidney transplant recipients started on growth hormone treatment in late puberty.

BACKGROUND: Growth retardation and its impact on adult height is considered to be one of the most common complications in patients with chronic kidney disease (CKD). Treatment with recombinant human growth hormone (rhGH) has been effective in improving growth in kidney transplantation (KTx) patients, but little data are available on adult height in patients who began rhGh treatment in late puberty. METHODS: Near-adult height was evaluated in 13 KTx patients treated with rhGH [growth hormone group (GHGr); dose 9.33 mg/m2 per week] for a period of at least 18 months. At initiation of rhGH treatment, testicular volume was >8 ml and serum testosterone was >1 ng/ml compared with the control group (CGr) of ten KTx patients who did not receive rHGH. All subjects were of similar chronological age and bone age and had similar creatinine clearance (CrCl) levels, cumulative corticoid dose, height standard deviation score (SDS), target height SDS, and target height:initial height at the beginning of the study. RESULTS: Near-adult height was significantly greater in the GHGr than in the CGr (-1.8 ± 0.8 vs. -2.9 ± 1.1; p = 0.018). The difference between initial height and near-adult height in the GHGr revealed a significant height gain (initial height -3.1 ± 1.1; near-adult height -1.8 ± 0.8 SDS, respectively; delta 1.2 ± 0.3; p = 0.021). The CrCl level was not significantly different between the GHGr and CGr at either at study initiation or when attaining near-adult height (p = 0.74 and p = 0.23, respectively). CONCLUSIONS: Treatment with rhGH was effective in improving adult height in KTx patients who began treatment in late puberty, without any effect on renal function.

Biopsias de vigilancia en niños con trasplante renal. Análisis de lesiones histológicas: su importancia en la detección de rechazo subclínico y otras implicancias pronosticas a 1 año luego del trasplante / Surveillance biopsies in children with renal transplantation. Analysis of histological lesions: its importance in the detection of subclinical rejection and other prognostic implications at 1 year after transplantation

INTRODUCCION En población adulta con trasplante renal (TxR), los hallazgos histológicos en biopsias de vigilancia a 1 ano post TxR son correlato independiente de sobrevida del injerto a largo plazo. Los estudios de población pediátrica con TxR y biopsia de protocolo son escasos. Otro hallazgo importante referente al pronóstico del injerto fue demostrar que la presencia de anticuerpos específicos contra antígenos del donante (ADE) se asocian a rechazo mediado por anticuerpos (RMAC) y pérdida de injerto. Además, variables "sociales", como la no adherencia al tratamiento, pueden ser factores de riesgo de histología desfavorable en la biopsia y también de ADE. OBJETIVO Conocer la prevalencia de lesiones histológicas favorables y desfavorables para la sobrevida del injerto en biopsias de protocolo en niños a 1 año post TxR e identificar variables predictivas de dichas lesiones. MÉTODOS Estudio de cohorte prospectivo que incluyo a todo receptor de un 1er TxR en el Hospital JP Garrahan entre el 01/06/2018 al 30/05/2019. Las lesiones fueron agrupadas, según su riesgo histológico en favorables, y desfavorables. Se consideraron favorables; 1) cambios morfológicos menores, con ausencia de inflamación y/o fibrosis y/o glomerulopatía crónica o glomerulonefritis, 2) inflamación Intersticial Aguda sin fibrosis intersticial ni cambios glomerulares y 3) fibrosis Intersticial Leve con ausencia de inflamación intersticial. Se consideraron desfavorables; 1) fibrosis intersticial moderada-severa sin inflamación 2) rechazo agudo o crónico activo mediada por anticuerpos o por células T 3) enfermedad glomerular de novo 4) nefropatía asociada al virus del Polioma. En forma simultánea a la biopsia se determino presencia de ADE. Como marcador de no adherencia se utilizó el Coeficiente de variación (CV) de TAC y/o SRL ≥ 25%. RESULTADOS Fueron incluidos 30 niños. El 93% (n= 28) tuvieron histología "favorable"; 26 con cambios morfológicos mínimos y 2 con fibrosis leve. Tuvieron histología desfavorable 2; uno con recidiva de enfermedad de base y otro con RMAC y ADE, ambos con coeficiente variación de sirolimus y/o tacrolimus > 25%. Ningún paciente tuvo rechazo subclínico. El CV de TAC o SRL fue <25% en el 77% de los pacientes (n=23), que por interrogatorio eran adherentes a la inmunosupresión; 7 tuvieron CV >25% (r; 25.4 %-35.6%), con toma de medicación errática. Aquellos con CV <25%, tenían en promedio 1.4 veces más probabilidad de tener una lesión favorable (p<0.01) comparados con CV >5%. DISCUSIÓN En esta cohorte las lesiones favorables, ADE negativos y coeficiente de variación de TAC < al 25% fueron las más prevalentes. Nuestros hallazgos coinciden con los de la literatura, con un mayor porcentaje de casos de histología "favorable". La detección de ADE y/o CV >25% ameritan vigilancia cercana de adherencia al tratamiento. Es imperativo el seguimiento longitudinal de esta cohorte

Therapeutic monitoring of pediatric transplant patients with conversion to generic tacrolimus / Monitorización terapéutico del tacrolimus en pacientes pediátricos trasplantados sujetos a conversión de marcas comerciales

Objective: Therapeutic monitoring during interchange of tacrolimus commercial formulations is essential to ensure similar exposure in transplant patients. However, there are limited data in the pediatric transplant population. This study aims to evaluate exposure, safety and efficacy in maintenance pediatric transplant patients under generic tacrolimus substitution. Method: Pediatric patients who underwent interchange of tacrolimus formulations were detected by the Service of Pharmacy and included in this study. Tacrolimus trough levels (C0), laboratory parameters and clinical characteristics were recorded before and after the switch. Statistical analysis was performed using Wilcoxon matched pair t-test. Results: In total, 10 patients with kidney, liver, heart and hematopoietic stem cell transplantation received the innovator and switched to the generic product. The median (range) of the C0 normalized by the dose before and after switch was 74.8 [(ng/ml)/(mg/kg)] (13.8-518.4) and 65.1 [(ng/ml)/(mg/ kg)] (13.5-723.5), respectively (p>0.05). Tacrolimus dose was 0.070(mg/kg) (0.024-0.461) and 0.069(mg/kg) (0.017-0.571) for the innovator and generic formulation, respectively, with no difference when comparing both values (p>0.05). Laboratory parameters did not change after conversion (p>0.05). Adverse events, acute rejection, death and graft loss were not observed. Conclusion: In our study population, no significant differences in terms of laboratory parameters, drug exposure and dose were observed. We emphasize the need of close monitoring to ensure a safe interchange, especially in vulnerable populations such as the pediatric (AU)

Objetivo: La monitorización terapéutica durante el intercambio de marcas comerciales de inmunosupresores es esencial para mantener una similar exposición al fármaco en pacientes trasplantados. Sin embargo, la información disponible en trasplante pediátrico es limitada. El objetivo del trabajo fue evaluar la exposición, seguridad y eficacia en pacientes pediátricos trasplantados en etapa de mantenimiento, sujetos a intercambio entre el producto innovador y el genérico de tacrolimus. Método: El Área de Farmacia del hospital detectó aquellos pacientes sujetos a intercambio de formulaciones según la disponibilidad de medicamentos. Se obtuvieron las concentraciones de tacrolimus en el valle (C0), parámetros de laboratorio y características clínicas antes y después del intercambio. El análisis estadístico se realizó mediante el test de muestras pareadas de Wilcoxon. Resultados: Se incluyeron 10 pacientes con trasplante renal, hepático, cardíaco y de células hematopoyéticas. La mediana (rango) del C0 normalizado por la dosis pre y post intercambio fue 74,8[(ng/ml)/(mg/kg)](13,8-518,4) y 65,1[(ng/ml)/(mg/kg)] (13,5-723,5), respectivamente (p>0,05). La dosis de tacrolimus fue 0,070(mg/kg) (0,024-0,461) y 0,069(mg/kg) (0,017-0,571) para el innovador y el genérico, respectivamente (p>0,05). Los parámetros de laboratorio de funcionalidad renal y hepática no cambiaron con la conversión de marcas (p>0,05). No se observaron eventos adversos, rechazo agudo, muerte o pérdida del injerto durante el periodo analizado. Conclusiones: En la población estudiada, no se observaron diferencias significativas en los parámetros de laboratorio, exposición al tacrolimus o dosis en el intercambio de marcas comerciales. Destacamos el rol de la monitorización terapéutica a la hora de garantizar una sustitución segura, especialmente en poblaciones vulnerables (AU)

Therapeutic monitoring of pediatric transplant patients with conversion to generic tacrolimus.

OBJECTIVE: Therapeutic monitoring during interchange of tacrolimus commercial formulations is essential to ensure similar exposure in transplant patients. However, there are limited data in the pediatric transplant population. This study aims to evaluate exposure, safety and efficacy in maintenance pediatric transplant patients under generic tacrolimus substitution. METHOD: Pediatric patients who underwent interchange of tacrolimus formulations were detected by the Service of Pharmacy and included in this study. Tacrolimus trough levels (C0), laboratory parameters and clinical characteristics were recorded before and after the switch. Statistical analysis was performed using Wilcoxon matched pair t-test. RESULTS: In total, 10 patients with kidney, liver, heart and hematopoietic stem cell transplantation received the innovator and switched to the generic product. The median (range) of the C0 normalized by the dose before and after switch was 74.8 [(ng/ml)/(mg/kg)] (13.8-518.4) and 65.1 [(ng/ml)/(mg/kg)] (13.5-723.5), respectively (p>0.05). Tacrolimus dose was 0.070(mg/kg) (0.024-0.461) and 0.069(mg/kg) (0.017- 0.571) for the innovator and generic formulation, respectively, with no difference when comparing both values (p>0.05). Laboratory parameters did not change after conversion (p>0.05). Adverse events, acute rejection, death and graft loss were not observed. CONCLUSION: In our study population, no significant differences in terms of laboratory parameters, drug exposure and dose were observed. We emphasize the need of close monitoring to ensure a safe interchange, especially in vulnerable populations such as the pediatric.

Objetivo: La monitorización terapéutica durante el intercambio de marcas comerciales de inmunosupresores es esencial para mantener una similar exposición al fármaco en pacientes trasplantados. Sin embargo, la información disponible en trasplante pediátrico es limitada. El objetivo del trabajo fue evaluar la exposición, seguridad y eficacia en pacientes pediátricos trasplantados en etapa de mantenimiento, sujetos a intercambio entre el producto innovador y el genérico de tacrolimus. Método: El Área de Farmacia del hospital detectó aquellos pacientes sujetos a intercambio de formulaciones según la disponibilidad de medicamentos. Se obtuvieron las concentraciones de tacrolimus en el valle (C0), parámetros de laboratorio y características clínicas antes y después del intercambio. El análisis estadístico se realizó mediante el test de muestras pareadas de Wilcoxon. Resultados: Se incluyeron 10 pacientes con trasplante renal, hepático, cardíaco y de células hematopoyéticas. La mediana (rango) del C0 normalizado por la dosis pre y post intercambio fue 74,8[(ng/ml)/(mg/kg)](13,8-518,4) y 65,1[(ng/ml)/(mg/kg)] (13,5-723,5), respectivamente (p>0,05). La dosis de tacrolimus fue 0,070(mg/kg) (0,024-0,461) y 0,069(mg/kg) (0,017-0,571) para el innovador y el genérico, respectivamente (p>0,05). Los parámetros de laboratorio de funcionalidad renal y hepática no cambiaron con la conversión de marcas (p>0,05). No se observaron eventos adversos, rechazo agudo, muerte o pérdida del injerto durante el periodo analizado. Conclusiones: En la población estudiada, no se observaron diferencias significativas en los parámetros de laboratorio, exposición al tacrolimus o dosis en el intercambio de marcas comerciales. Destacamos el rol de la monitorización terapéutica a la hora de garantizar una sustitución segura, especialmente en poblaciones vulnerables.

Donor-specific anti-HLA antibodies in pediatric renal transplant recipients with creeping creatinine: Prevalence, histological correlations, and impact on patient and graft survival.

Donor-specific anti-HLA antibodies (DSA) causing CAMR are responsible for a high proportion of long-term graft failures after RTX. We studied the prevalence of DSA in RTX children biopsied for creeping Cr, its relationship with NA, and patient and graft survival according to histopathology. Between 2008 and 2013, 92 children were biopsied at a median of 38 months post-RTX. At biopsy, the prevalence of DSA was 49% and C4d 70%. NA rate was 45%, higher in adolescents (60%). Most frequent diagnoses were CAMR (72%) and interstitial fibrosis with tubular atrophy (IFTA) (28%). Forty-five of 66 patients with CAMR (68%) had detectable DSA. Twenty-one DSA-negative patients with CAMR had histological damage (IFTA + C4d positivity). C4d was detected in 64 of 66 biopsies with CAMR. Recipients with IFTA alone had neither C4d, nor detectable DSA, and were adherent. Graft survival at five yr was 89% in patients with CAMR, 79% in those with CAMR + TCMR Banff I, 33% in those with CAMR + TCMR Banff II, and 96% in those with IFTA. ABMR and complement activation were frequent in children biopsied for creeping Cr. Recipients with DSA were more likely to be non-adherent and have CAMR or CAMR + TCMR and worse graft survival.

Therapeutic monitoring of pediatric renal transplant patients with conversion to generic cyclosporin.

BACKGROUND: Cyclosporin is a calcineurin inhibitor widely used in renal transplant patients to prevent organ rejection. Several position papers have been published but no reports on the practical experience in pediatric patients undergoing conversion between cyclosporin innovator and generic products are available. OBJECTIVE: To evaluate the pharmacokinetics and safety as part of therapeutic monitoring of cyclosporin in renal transplant pediatric patients who switch from the innovator to the generic formulation in Argentina. SETTING: Hospital de Pediatría JP Garrahan, Buenos Aires, Argentina. METHODS: Stable pediatric renal transplant patients (6 months post-transplant) switched from the innovator to the generic formulation of cyclosporin microemulsion capsule. Cyclosporin pharmacokinetic parameters were obtained while taking the innovator and after starting with the generic formulation. Blood samples were drawn before and 1, 2, and 3 h after drug administration and subsequently quantified. Pharmacokinetic parameters were obtained by means of a Bayesian approach. MAIN OUTCOMES MEASURE: Cyclosporin pharmacokinetic parameters (area under the curve, AUC; Blood concentration after 2 h, C2), adverse events and graft rejection. RESULTS: A total of 12 patients were included. Median (range) age and time post-transplant were 10.7 years (6.5-17.7) and 8.3 years (3.4-14.0), respectively. Two patients or their parents did not consent to the switch. Median (range) dose normalized cyclosporin AUC and C2 were 1.15 (mg*h/L)/mg/kg (0.72-3.0) and 265.5 (ng/ml)/mg/kg (120.8-725.7), respectively, on the innovator therapy and 1.05 (mg*h/L)/mg/kg (0.54-2.22) and 317.1 (ng/ml)/mg/kg (116.7-564.7) for the generic drug after the switch. The median (range) percentage of change in the AUC and C2 when switching between formulations were 16.7 % (0.7-56.7) and 13.1 % (3.7-68.6), respectively. No significant changes in serum creatinine levels were registered when comparing before and after substitution of products. Adverse events (number of events) recorded 5 months before and after the switch included hirsutism (2), hypertension (2), and gingival hyperplasia (1). CONCLUSION: Conversion of cyclosporin from innovator brand to generic in pediatric renal transplant patients needs to be closely monitored.