ABSTRACT
Abstract Introduction: BK virus (BKV) infection in renal transplant patients may cause kidney allograft dysfunction and graft loss. Accurate determination of BKV viral load is critical to prevent BKV-associated nephropathy (BKVAN) but the cut-off that best predicts BKVAN remains controversial. Objective: To evaluate the performance of a commercial and an in-house qPCR test for quantitative detection of BK virus in kidney transplant recipients. Methods: This was a prospective study with kidney transplant recipients from two large university hospitals in Brazil. Patients were screened for BKV infection every 3 months in the first year post-transplant with a commercial and an in-house real time polymerase chain reaction (qPCR) test. BKVAN was confirmed based on histopathology. The area under the curve for plasma qPCR was determined from receiver operating characteristic analysis. Results: A total of 200 patients were enrolled. Fifty-eight percent were male, 19.5% had diabetes mellitus, and 82% had the kidney transplanted from a deceased donor. BKV viremia was detected in 32.5% and BKVAN was diagnosed in 8 patients (4%). BKVAN was associated with viremia of 4.1 log copies/mL, using a commercial kit. The cut-off for the in-house assay was 6.1 log copies/mL. The linearity between the commercial kit and the in-house assay was R2=0.83. Conclusion: Our study shows that marked variability occurs in BKV viral load when different qPCR methodologies are used. The in-house qPCR assay proved clinically useful, a cheaper option in comparison to commercial qPCR kits. There is an urgent need to make BKV standards available to the international community.
Resumo Introdução: A infecção pelo vírus BK (BKV) em pacientes de transplante renal pode levar a disfunção do aloenxerto renal e perda do enxerto. A determinação precisa da carga viral do BKV é fundamental para prevenir a nefropatia associada ao BKV (BKVAN), mas o ponto de corte de melhor valor preditivo para BKVAN ainda é foco de debates. Objetivo: Avaliar o desempenho de um teste de qPCR comercial e outro desenvolvido internamente para detecção quantitativa de vírus BK em receptores de transplante renal. Métodos: O presente estudo prospectivo incluiu receptores de transplante renal de dois grandes hospitais universitários no Brasil. Os pacientes foram testados para infecção por BKV a cada três meses no primeiro ano pós-transplante com um teste comercial de reação em cadeia de polimerase quantitativa em tempo real (qPCR) e outro desenvolvido internamente. A presença de BKVAN foi confirmada com base na histopatologia. A área sob a curva para o qPCR plasmático foi determinada a partir da análise da característica de operação do receptor. Resultados: Um total de 200 pacientes foram incluídos. Cinquenta e oito por cento eram do sexo masculino, 19,5% tinham diabetes mellitus e 82% tiveram seus rins transplantados de doadores falecidos. Viremia de BKV foi detectada em 32,5% dos pacientes e oito (4%) foram diagnosticados com BKVAN. BKVAN foi associada a viremia de 4,1 log cópias/mL usando o kit comercial. O corte para o ensaio interno foi de 6,1 log cópias/mL. A linearidade entre o kit comercial e o ensaio interno foi R2 = 0,83. Conclusão: Nosso estudo demonstrou uma acentuada variabilidade na carga viral de BKV quando diferentes metodologias de qPCR foram utilizadas. O ensaio interno de qPCR mostrou-se clinicamente útil, além de ser uma opção menos onerosa em relação aos kits comerciais de qPCR. Há uma necessidade urgente de se definir padrões de BKV para a comunidade internacional.
Subject(s)
Humans , Male , Female , Adult , Postoperative Complications/virology , Tumor Virus Infections/virology , Kidney Transplantation , BK Virus/isolation & purification , Viral Load , Polyomavirus Infections/virology , Postoperative Complications/blood , Tumor Virus Infections/blood , Polymerase Chain Reaction , Prospective Studies , Polyomavirus Infections/bloodABSTRACT
BACKGROUND: The susceptibility to adverse outcome from critical illness (occurrence of sepsis, septic shock, organ dysfunction/failure, and mortality) varies dramatically due to different degrees of inflammatory response. An over expression of tumor necrosis factor alpha (TNF-α) can lead to the progression of the inflammatory condition. OBJECTIVE: We assessed the relationship of the genotype distribution of -308G >A TNF-α polymorphism with regard to the development of sepsis, septic shock, higher organ dysfunction or mortality in critically ill patients. METHODS: Observational, hospital-based cohort study of 520 critically ill Caucasian patients from southern Brazil admitted to the general ICU of São Lucas Hospital, Porto Alegre, Brazil. Patients were monitored daily from the ICU admission day to hospital discharge or death, measuring SOFA score, sepsis, and septic shock occurrences. The -308G >A TNF-α SNP effect was analyzed in the entire patient group, in patients with sepsis (349/520), and in those who developed septic shock (248/520). RESULTS: The genotypic and allelic frequencies were -308GG = 0.72; -308GA = 0.27; -308AA = 0.01; -308G = 0.85; -308A = 0.15. No associations were found with sepsis, septic shock, organ dysfunction, and/or mortality rates among the TNF-α genotypes. Our results reveal that the -308G >A TNF-α SNP alone was not predictive of severe outcomes in critically ill patients. CONCLUSION: The principal novel input of this study was the larger sample size in an investigation with -308G > A TNF-α SNP. The presence of -308A allele is not associated with sepsis, septic shock, higher organ dysfunction or mortality in critically ill patients.
Subject(s)
Female , Humans , Male , Hospital Mortality , Multiple Organ Failure/mortality , Polymorphism, Genetic/genetics , Sepsis/mortality , Tumor Necrosis Factor-alpha/genetics , Cohort Studies , Critical Illness , Gene Frequency , Genotype , Multiple Organ Failure/genetics , Phenotype , Predictive Value of Tests , Sepsis/geneticsABSTRACT
A síndrome de disfunção de múltiplos órgãos e sistemas (DMOS) e a disfunção renal aguda compartilham muitos dos fatores fisiológicos envolvidos em seu desenvolvimento. Estudos recentes correlacionam suscetibilidades individuais, determinadas geneticamente, à disfunção de órgãos em pacientes criticamente enfermos, situação em que o gene da enzima conversora da angiotensina (ECA) poderia ser um candidato para elucidar predisposição ou risco genético. Nosso objetivo foi examinar os efeitos da presença de dois polimorfismos, I/D e -262A > T, na disfunção renal em pacientes agudamente graves do Sul do Brasil. O escore SOFA (sequential organ failure assessment) à admissão e a tendência da função renal (medida pelo escore renal diário do SOFA) foram determinados em pacientes de unidade de terapia intensiva (UTI). Um total de 153 pacientes adultos (79 homens) foi incluído no estudo. Houve monitoração diária da função renal durante toda a permanência na UTI e também pós-UTI. Observou-se a progressão para insuficiência renal (SOFA 3 e 4) nos primeiros sete dias de internação em UTI, bem como necessidade de diálise. As frequências genotípicas gerais em nossa amostra foram II = 0,17; ID = 0,46; DD = 0,37; e AA = 0,30; AT = 0,55; TT = 0,15; e as frequências alélicas foram I = 0,40, D = 0,60; e A = 0,56; T = 0,44. Este é o primeiro estudo para verificar a influência de polimorfismos I/D e -262A > T da ECA em disfunção renal aguda em pacientes críticos. Nenhuma associação significativa foi encontrada entre os genótipos ou as frequências alélicas e a evolução da função renal. Os polimorfismos I/D e -262A > T da ECA não têm impacto significativo sobre a evolução da função renal durante a primeira semana de internação na UTI nem exercem qualquer influência sobre a mortalidade em pacientes graves.
Multiple organ failure syndrome and acute renal dysfunction share many of physiologic factors involved in their development. Recent studies correlate the susceptibility to organ dysfunction in critically ill patients with genetic inheritance. Many of them consider ACE gene could be a possible candidate to elucidate a genetic predisposition or a genetic risk factor. We aimed to examine the effects of I/D and -262A > T ACE polymorphisms in the renal function in severely ill southern Brazilians patients. A multi-organic worldwide known failure score, the SOFA (sequential organ failure assessment), was used to determine the basal health state at first day (ICU admission). Considering admission SOFA score and trend of renal function (measured by daily renal SOFA scores, with daily measure of serum creatinine and diuresis), we hypothesize that ACE polymorphisms could influence in the trend of renal function in ICU patients. A total of 153 critically ill adult patients (79 men) were included in this study. We monitored the patients daily during their entire ICU and post-ICU (hospital) stay (measured from the ICU admission day to a maximum of 224 days). We observed progression to renal failure (SOFA scores 3 and 4) in first seven days of ICU stay and need for dialysis. The general genotypic frequencies in our sample were II = 0.17; ID = 0.46; DD = 0.37 and AA = 0.30; AT = 0.55; TT = 0.15, and the allelic frequencies were I = 0.40; D = 0.60 and A = 0.56; T = 0.44. This is the first study to verify the influence of I/D and -262A > T ACE polymorphisms in acute renal dysfunction among critically ill patients. No significant association was found between genotypes or allele frequencies and the trend of the renal function. The I/D and -262A > T ACE polymorphisms have no significant impact on the trend of renal function during the first week of ICU stay, neither any influence in mortality in critically ill patients.