Analysis of Factors Related to the Success of Pediatric Kidney Transplantation: A 35 Years Experience.

BACKGROUND: Despite the significant improvement results over the past 20 years, pediatric kidney transplantation remains a challenge. Chronic rejection, thrombosis, and recurrence of the primary disease are frequent causes of graft loss that have been little studied. Therefore, our objective is to analyze factors related to a better prognosis, which can be used to improve future strategies to allow higher pediatric transplant success rates. METHODS: A retrospective cohort study with patients under 15 years old submitted for kidney transplantation at the Hospital das Clínicas da UNICAMP between January 1, 1987, and January 1, 2022. Age, patient weight, time and type of dialysis, use of anticoagulation, complications, ischemia time, and donor weight were analyzed and related to graft loss. The significance level adopted for the statistical tests was 5%. RESULTS: One hundred ninety-two medical records were anaThe mean follow-up time was 11 years, and the mean graft duration was ration 8.5 years. The main causes of graft loss were chronic dysfunction, thrombosis, and acute cellular rejection. Thrombosis presented significantly with the donor's body mass index and second transplantation. There was no correlation between the analyzed variables and chronic dysfunction or acute cellular rejection. DISCUSSION: Thrombosis remains the main cause of early graft loss, followed by acute cellular rejection. Measures such as thrombophilia screening and thromboprophylaxis have been proposed to improve results. However, they are still not standardized. CONCLUSION: The main causes of graft loss were chronic dysfunction, thrombosis, and acute cellular rejection. Only the thrombosis was related to the donor's body mass index and a second transplantation.

Collaborative Brazilian pediatric renal transplant registry (CoBrazPed-RTx): A report from 2004 to 2018.

The Brazilian collaborative registry for pediatric renal transplantation began in 2004 as a multicenter initiative aimed at analyzing, reporting, and disseminating the results of pediatric renal transplantation in Brazil. Data from all pediatric renal transplants performed from January 2004 to May 2018 at the 13 participating centers were analyzed. A total of 2744 pediatric renal transplants were performed in the thirteen participating centers. The median age at transplantation was 12.2 years, with the majority being male recipients (56%). The main underlying diseases were CAKUT (40.5%) and glomerulopathy (28%). 1981 (72%) of the grafts were from deceased donors (DD). Graft survival at one year (censored by death) was 94% in the live donor group (LD) and 91% in the DD group (log-rank test P < 0.01). The patient's survival at one and 5 years was 97% and 95% for the LD group and 96% and 93% for the DD group (log-rank test P = 0.02). The graft loss rate was 19% (n = 517), more frequently caused by vascular thrombosis (n = 102) and chronic graft nephropathy (n = 90). DD recipients had 1.6 (1.0-2.2) times greater chance of death and 1.5 (1.2-1.8) times greater chance of graft loss compared to LD recipients. The mortality rate was 5.4% (n = 148), mainly due to infection (n = 69) and cardiovascular disease (n = 28). The results of this collaborative pediatric renal transplant record are comparable to other international registries, although we still have a high infection rate as a cause of death.

Active human Cytomegalovirus infection and Glycoprotein B genotypes in Brazilian pediatric renal or hematopoietic stem cell transplantation patients

A prospective analysis of active Human Cytomegalovirus infection (HCMV) was conducted on 33 pediatric renal or hematopoietic stem cell post-transplant patients. The HCMV-DNA positive samples were evaluated for the prevalence of different gB subtypes and their subsequent correlation with clinical signs. The surveillance of HCMV active infection was based on the monitoring of antigenemia (AGM) and on a nested polymerase chain reaction (N-PCR) for the detection of HCMV in the patients studied. Using restriction analysis of the gB gene sequence by PCR-RFLP (Restriction Fragment Length Polymorphism), different HCMV strains could be detected and classified in at least four HCMV genotypes. Thirty-three pediatric recipients of renal or bone marrow transplantation were monitored. Twenty out of thirty-three (60.6 percent) patients demonstrated active HCMV infection. gB1 and gB2 genotypes were more frequent in this population. In this study, we observed that gB2 had correlation with reactivation of HCMV infection and that patients with mixture of genotypes did not show any symptoms of HCMV disease. Future studies has been made to confirm this.

Active human cytomegalovirus infection and glycoprotein b genotypes in brazilian pediatric renal or hematopoietic stem cell transplantation patients.

A prospective analysis of active Human Cytomegalovirus infection (HCMV) was conducted on 33 pediatric renal or hematopoietic stem cell post-transplant patients. The HCMV-DNA positive samples were evaluated for the prevalence of different gB subtypes and their subsequent correlation with clinical signs. The surveillance of HCMV active infection was based on the monitoring of antigenemia (AGM) and on a nested polymerase chain reaction (N-PCR) for the detection of HCMV in the patients studied. Using restriction analysis of the gB gene sequence by PCR-RFLP (Restriction Fragment Length Polymorphism), different HCMV strains could be detected and classified in at least four HCMV genotypes. Thirty-three pediatric recipients of renal or bone marrow transplantation were monitored. Twenty out of thirty-three (60.6%) patients demonstrated active HCMV infection. gB1 and gB2 genotypes were more frequent in this population. In this study, we observed that gB2 had correlation with reactivation of HCMV infection and that patients with mixture of genotypes did not show any symptoms of HCMV disease. Future studies has been made to confirm this.

Avaliação de cateteres de diálise peritoneal pela microscopia eletrônica de varredura / Evaluation of peritoneal dialysis catheters using scanelectronic microscopy

Objetivos: avaliação pela microscopia eletrônica de varredura (MEV) das superfícies interna e externa da região de conexão com o Titânio, e da regiãodistal (ponta e furos) de cateteres de diálise peritoneal retirados de crianças em programa de diálise peritoneal crônica. Material e Métodos: 11 cateteresretirados de pacientes com 02 a 16 anos de idade, com mediana de tempo de uso de 36 meses. Dois cateteres sem uso foram analisados paracomparação. Foram confeccionados fragmentos das regiões citadas, e avaliadas as características das fibras que compõem o material e a presença e localizaçãode microorganismos e de biofilme. Resultados: Foi demonstrado que os cateteres sem uso apresentavam fibras com disposição regular, mas comfalhas discretas de acabamento nos furos e irregularidades grosseiras nas pontas. Nos cateteres retirados, havia desestruturação das fibras, irregularidadena sua disposição, com formação de crateras e desgaste no contorno dos furos. Na região da conexão com o Titânio, as fibras tinham aspecto deesmagamento. Foi observado em 10/11 cateteres retirados, imagens sugestivas de microorganismos dispostos tanto nas regiões intraluminais como nasextraluminais, como dentro dos furos, sendo que a ponta foi a região que continha a maior freqüência e intensidade de nichos de microorganismos.Conclusões: A região de conexão com o Titânio apresenta características que podem torná-la mais vulnerável à ocorrência de perfuração. O processo defabricação da ponta do cateter deveria ser reavaliado, com fins redução da colonização deste local.

Objective: To evaluate the external and internal surfaces of the titanium connecting portion and the distal region (extremity and holes) of peritoneal dialysiscatheters from children undergoing chronic peritoneal dialysis through scan electronic microscopy Methods: Eleven catheters, with an average time of use of36 months, were taken from patients between 2 and 16 years. Two catheters without any usage were analyzed for comparison. Fragments were studied toestablish the characteristics of the fibers composing the material and the presence and location of microorganisms and biofilm. Results: It was demonstratedthat the catheters without any usage presented fibers with regular disposition, but with discrete failures in the holes and strong irregularities in the extremities.In the used catheters, the original disposition and structure of the fibers showed marked irregularitywith the formation of craters and erosion around the holes.In the titanium connecting portion, the fibers looked like they had been smashed. In 10 out of 11 examined catheters, there were images suggestive ofmicroorganisms disposed in the intraluminal regions as well as in the extraluminal ones. They were found inside the holes, but the extremity was the region thatexhibited the higher frequency and intensity of microorganisms niches. Conclusion: the titanium connecting portion of the catheters presents characteristicsthat can make it more vulnerable to occurrence of perforation. The manufacturing of the catheter extremity should be reevaluated in order to reduce the chanceof colonization of this region.

Angiomatose bacilar pós-transplante renal: apresentação de um caso / Bacillary angiomatosis after kidney transplantation

A bartonela causa a Doença da arranhadura do gato, mas em imunossuprimidos pode levar à doença sistêmica, denominada angiomatose bacilar.Descrição do caso: Masculino, 15 anos, transplantado há 3 anos, em uso de FK, MMF e prednisona com função renal preservada. Refere tumoraçãoavermelhada e dolorosa na região mandibular esquerda há 30 dias, com febre elevada há 7 dias. Esta em regular estado geral, descorado, 39ºC, commassa submandibular de 4cm de diâmetro, consistência carnosa com vesículas na superfície e hepato-esplenomegalia. Bx da massa compatível com Angiomatose Bacilar. Evoluiu bem com Cloranfenicol e Eritromicina. Apresentou elevação da creatinina sérica, sendo feita hipótese de rejeição e realizadopulso de metilprednisolona com normalização da função renal. Conclusões: Como a soroprevalência de Bartonela, em gatos, é elevada em nosso meio, deve-se estar alerta para seu diagnóstico. Pacientes imunossuprimidos podem apresentar formas sistêmicas graves de infecções comuns que, pelararidade, podem ser diagnosticadas tardiamente e carrear maior morbidade.

Bartonela sp causes cat scratch disease but in immunosuppressed hosts it can be associated with a systemic disease named bacillary angiomatosis.Description of case: A 15-year old boy with a successful kidney transplant for 3 years had been treated with FK, MMF and prednisone. He reported ared and painful mass in the left submandibular area for 30 days, and high fever for the last 7 days. He looked sick, pale and had a submandibular mass of 4cm in diameter with vesicles in its surface and hepatosplenomegaly. Biopsy of the mass was suggestive of bacillary angiomatosis. He was treated withchloramphenicol and erythromycin and had a favorable course. An increase of creatinine, interpreted as rejection, was successfully managed with a pulseof methylprednisolone. Conclusions: As the prevalence of bartonelosis in cats is elevated in our country, physicians should be aware of that diagnosticpossibility. Immunocompromised hosts may present rare systemic forms of common diseases that can be diagnosed late and produce sequels.

Fístula arteriovenosa em crianças e adultos jovens / Arteriovenous fistula in children and young adults

Objetivo: Com a introdução e o aprimoramento de técnicas para a realização de fístulas arteriovenosas(FAV) em crianças, pacientes renais crônicos puderam iniciar tratamento com hemodiálise sem a necessidadede uso de shunts externos. Métodos: Com o objetivo avaliar os resultados da confecção de fístulas arteriovenosasem crianças e adultos jovens de baixo peso e os fatores de risco relacionados. Foram levantados retrospectivamenteos prontuários de 31 pacientes submetidos a 35 FAV, com idade variando de cinco a 24 anos, com pesoentre 16 e 50kg. Os fatores de risco estudados foram hipertensão arterial, antecedentes de trombose, tendência àhipovolemia e presença de hipercolesterolemia. Resultados: O índice de perda observado foi de 25% em pacientes com menos de 20kg e de 22,2% naqueles com mais de 20kg, resultados comparáveis aos da literatura. Conclusões: Observou-se que fístulas proximais não sofreram trombose; não houve relação entre a perda da FAV e os fatores de risco estudados e observou-se um índice de perda tardia de 23,5% nos pacientes que não estavam sendo submetidos à hemodiálise. Nos pacientes que utilizavam a FAV não se observou perda da mesma.

Background: Since the development of operative techniques for arteriovenous fistula (AVF) creation, chronic hemodialysis for treatment of end-stage renal disease in children and young adults became an actual therapeuticoption, obviating the need for external shunts. Purpose: To report our experience with surgically created AVF in 31 patients, aged 5 to 24 years old, relating long-term fistula patency with risk factors such as arterial hypertension, previous thrombosis events, tendency to hypovolemy, hypercholesterolemy, vein caliber and routine use of the fistula. Results: Overall rate of fistula thrombosis was 22,8%, being 25% in patients weighing less than 20kg and 22,2% in those over 20kg. All fistulas performed on proximal arm veins were patent after 5 to 32 months follow-up. Unused AV fistulas apparently had an increased risk of thrombosis when compared to fistulas routinelly used for hemodialysis access. None of the remainy risk factors studied showed estatistical association withloss of patency. Conclusion: AV fistulas can be safely performed in children with success rate comparable to those observed in older patients. Vein caliber and routine use of the fistula appears to have a strong influence on long term patency.

Peritonite primária e síndrome nefrótica na infância / Primary peritonitis in children with nephrotic syndrome

Avaliar os fatores predisponentes, métodos diagnósticos, agentes etiológicos e evolução da peritonite primária na síndrome nefrótica (SN) da infância. Métodos: Foram analisados, de janeiro de 1989 a fevereiro de 1997, todos os episódios de peritonite confirmados por citologia do líquido ascítico com celularidade >50cels/mm³, com predomínio de neutrófilos e/ou cultura positiva do líquido ascítico ou da hemocultura. Resultados: Foram estudados 18 episódios que ocorreram em 14 pacientes, de 1 a 11 anos de idade, sendo 12 do sexo masculino. Onze eram córtico-sensíveis com recidivas freqüentes, 6 córtico-resistentes e 1 nunca havia sido tratado. Em sete episódios, os pacientes não estavam em uso de imunossupressão. Somente quatro episódios foram precedidos por infecção prévia: dois casos de sinusite e dois de celulite que precederam a peritonite em 22 a 30 dias. O tempo de história foi de um a sete dias, com mediana de um dia, preponderando as queixas de dor abdominal (18/18), febre (12/18) e distensão abdominal (5/18). A citologia peritoneal avaliada em 14/18 mostrou celularidade de 80 a 352 mil células/mm³. A cultura do líquido foi positiva em 9/18 e a hemocultura em 7/18 casos. Em três casos, ambas as culturas foram positivas. Em seis casos, não houve isolamento do agente. Os agentes etiológicos encontrados foram: E. coli - quatro casos; Klebsiella sp - dois casos; Streptococcus pneumoniae - quatro casos; Stafilo aureus coagulase-negativo - um caso; Acynetobacter sp - um caso. A maioria dos pacientes apresentou melhora clínica evidente (13/18) em 48 h de antibioticoterapia de largo espectro. Um paciente faleceu. Conclusões: Não houve diferença significativa quanto às queixas, infecções precedentes, valores da citologia, do leucograma e da evolução dependente do agente etiológico ser gram negativo ou positivo. A cultura do líquido ascítico e do sangue são complementares para o diagnóstico da peritonite.