Impact of pretransplantation malnutrition risk on the clinical outcome and graft survival of kidney transplant patients / Impacto do risco de desnutrição pré-transplante no desfecho clínico e na sobrevida do enxerto de pacientes transplantados renais

ABSTRACT Background: The prevalence of malnourished patients before transplantation and the influence of malnutrition on graft and patient outcomes remain underestimated, despite being associated with higher postoperative morbidity and mortality. This study aimed to develop an easy nutritional screening tool and evaluate the impact of nutritional status on clinical outcome, graft survival (GS) and mortality risk in kidney transplant patients (KTP). Methods: In this retrospective cohort study including 451 KTP, we developed a score by using anthropometric, clinical, and laboratory measures performed in the pretransplant evaluation. The patients were stratified into 3 groups according to the final score: G1 (0 or 1 point)=low risk, G2 (2 to 4 points)=moderate risk, and G3 (>5 points)=high risk of malnutrition. The patients were monitored after transplantation at least 1 to 10 years. Results: Stratifying the 451 patients based on the pretransplant risk score, G1, G2, and G3 were composed of 90, 292, and 69 patients, respectively. Patients from G1 maintained the lowest serum creatinine levels at hospital discharge when compared with others (p = 0.012). The incidence of infection in the patients from G3 was higher than patients from G1 and G2 (p = 0.030). G3 recipients showed worse GS than G1 patients (p = 0.044). G3 patients showed almost threefold higher risk for graft loss (HR 2.94, 95% CI 1.084-7.996). Conclusions: KTP with higher malnutrition risk score were associated with worse outcomes and GS. The nutritional screening tool is easy to be used in clinical practice to evaluate the patient in preparation for kidney transplant.

RESUMO Antecedentes: A prevalência de pacientes desnutridos antes do transplante e a influência da desnutrição nos desfechos do enxerto e do paciente permanecem subestimadas, embora estejam associadas a maior morbimortalidade pós-operatória. Este estudo buscou desenvolver uma ferramenta simples de triagem nutricional e avaliar o impacto do estado nutricional no desfecho clínico, sobrevida do enxerto (SE) e risco de mortalidade em pacientes transplantados renais (PTR). Métodos: Neste estudo de coorte retrospectivo incluindo 451 PTR, desenvolvemos um escore usando medidas antropométricas, clínicas e laboratoriais tomadas na avaliação pré-transplante. Os pacientes foram estratificados em 3 grupos segundo a pontuação final: G1 (0-1 ponto) = baixo risco, G2 (2-4 pontos) = risco moderado e G3 (>5 pontos) = alto risco de desnutrição. Eles foram monitorados por pelo menos 1 a 10 anos após o transplante. Resultados: Os 451 pacientes foram estratificados em G1, G2 e G3, que consistiram em 90, 292 e 69 pacientes, respectivamente. Os pacientes do G1 mantiveram os menores níveis de creatinina sérica na alta hospitalar em relação aos demais (p = 0,012). A incidência de infecção nos pacientes do G3 foi maior que nos pacientes do G1 e G2 (p = 0,030). Os pacientes do G3 apresentaram SE pior do que os pacientes do G1 (p = 0,044) e um risco quase três vezes maior de perda do enxerto (HR 2,94; IC 95% 1,084-7,996). Conclusões: PTR com maior escore de risco de desnutrição foram associados a piores desfechos e menor SE. A ferramenta de triagem nutricional é fácil de usar na prática clínica para avaliar pacientes em preparação para transplante renal.

Impact of pretransplantation malnutrition risk on the clinical outcome and graft survival of kidney transplant patients.

BACKGROUND: The prevalence of malnourished patients before transplantation and the influence of malnutrition on graft and patient outcomes remain underestimated, despite being associated with higher postoperative morbidity and mortality. This study aimed to develop an easy nutritional screening tool and evaluate the impact of nutritional status on clinical outcome, graft survival (GS) and mortality risk in kidney transplant patients (KTP). METHODS: In this retrospective cohort study including 451 KTP, we developed a score by using anthropometric, clinical, and laboratory measures performed in the pretransplant evaluation. The patients were stratified into 3 groups according to the final score: G1 (0 or 1 point)=low risk, G2 (2 to 4 points)=moderate risk, and G3 (>5 points)=high risk of malnutrition. The patients were monitored after transplantation at least 1 to 10 years. RESULTS: Stratifying the 451 patients based on the pretransplant risk score, G1, G2, and G3 were composed of 90, 292, and 69 patients, respectively. Patients from G1 maintained the lowest serum creatinine levels at hospital discharge when compared with others (p = 0.012). The incidence of infection in the patients from G3 was higher than patients from G1 and G2 (p = 0.030). G3 recipients showed worse GS than G1 patients (p = 0.044). G3 patients showed almost threefold higher risk for graft loss (HR 2.94, 95% CI 1.084-7.996). CONCLUSIONS: KTP with higher malnutrition risk score were associated with worse outcomes and GS. The nutritional screening tool is easy to be used in clinical practice to evaluate the patient in preparation for kidney transplant.

Impact of early blood transfusion after kidney transplantation on the clinical outcomes and allograft survival.

INTRODUCTION: Anemia in chronic kidney disease is of great concern regarding blood transfusions and the possibility of allosensitization for future kidney transplants and the occurrence of rejection and allograft loss in the post-transplant period. The aim of this study was to evaluate the effect of early blood transfusion on the occurrence of rejections, allograft function and survival in the first year after transplantation. MATERIAL AND METHODS: This retrospective study was carried out with 445 patients submitted to kidney transplant allocated to two groups. The first group received early blood transfusions after transplant (n = 125, 28.09%), and the second group did not receive blood transfusions (n = 320, 71.91%). The patient outcomes were evaluated during a 1-year follow-up. RESULTS: 14 patients given blood transfusion (11.2%) lost their allograft in the first year in comparison with 8 (2.5%) without transfusion (p < 0.001). There were 9 deaths in each group, which corresponded to 7.2% of the patients who received blood transfusions and 2.81% of those who did not (p < 0.035). Patient hospitalization lasted 15 days in transfusion group and 8.5 days in non-transfusion group (p < 0.001). Creatinine levels were higher in the patients who received blood transfusion than in those without transfusion in the first and third months after transplantation (p = 0.012 and 0.038, respectively). During the first year, the patients who received blood products experienced more antibody-mediated rejection (ABMR) (13.60%) than patients who did not (4.38%) (p < 0.001). Those who received blood transfusions also developed de novo DSA in higher proportion than those without transfusion against both class I and class II HLA (p < 0.001). CONCLUSION: This study showed that blood transfusions in the first month after transplantation had a negative impact on kidney function, graft survival, and contributed to the development of de novo DSA, an increased risk of ABMR and infections.

Effect of Delayed Graft Function on the Outcome and Allograft Survival of Kidney Transplanted Patients from a Deceased Donor.

BACKGROUND: In kidney transplantation (KT), delayed graft function (DGF) is a significant early complication observed in the first week. The study aimed to investigate the impact of DGF on the outcome, allograft, and patient survival after KT with organs from deceased donors. METHODS: This retrospective study was conducted using 304 KT patients who received an organ from deceased donors from 2008 to 2018. The patients were divided into 2 groups, DGF positive (DGF+) and DGF negative (DGF-). The database containing the clinical, laboratory, and immunologic information of donors and recipients was statistically analyzed using the SSPS program. RESULTS: In this study, 189 (62.17%) were DGF+ and 115 (37.83%) were DGF-. Until 6 months after KT, the estimate glomerular filtration rate was better in group DGF-, but it was similar between the groups during 10-year follow-up. Graft losses were higher in DGF+ group than in the DGF- (P = .046). The serum creatinine level was persistently higher in DGF+ group until the sixth month (P ≤ .05). Allograft survival rates were better in patients who were DGF- (P = .033). Those who had DGF for more than 15 days had a worse graft survival (P = .003), but in 10 year follow-up, patient survival rates were similar (P = .705). CONCLUSION: DGF+ patients were associated with dialysis time before KT, ischemia time, and the donors' clinical status, such as age, organ quality, and serum creatinine. All these factors had a great impact on graft survival but not on patient survival.

Effects of immunotherapy induction on outcome and graft survival of kidney-transplanted patients with different immunological risk of rejection.

BACKGROUND: In kidney transplantation, immunotherapy with thymoglobulin (rATG) has been used to down-regulate the patient immune system. rATG is a powerful immunobiologic drug used to deplete lymphocytes to prevent early acute rejection. The aim of this research was to evaluate the effects of immunotherapy by rATG on graft suvival during a 9-year period in kidney-transplanted patients with different immunological profiles. METHODS: A sample of 469 patients were allocated into four groups (G) based on immunological risk of rejection: G1, low risk, not sensitized recipients, solid-phase immunoassay with single antigen beads (SPI-SAB) < 10%; G2, medium risk I, sensitized recipients, SPI-SAB ≥ 10 < 50%; G3, medium risk II sensitized (SPI-SAB ≥50%); and G4, high risk, sensitized recipients, SPI-SAB- donor-specific antibody positive (DSA+). Only patients from G3 and G4 received immunotherapy. RESULTS: Of 255 patients who received a kidney from a living donor (LD), 42 (16.47%) from all groups (G) had T-cell-mediated rejection (TCMR) and four (G1) lost their grafts, 8 (3.14%) had antibody-mediated rejection (AMR), and two lost their graft in G1 and G4. Of 214 patients who received a kidney from deceased donors (DD), 37 (17.29%) had TCMR with one lost graft in G1. AMR was shown in 13 (6.07%) patients, with three losses observed in G2. Statistical differences between the groups in the 9-year graft survival rate were found only in the comparison of G1 versus G2 (P = 0.005) and G2 versus G4 (P = 0.047) for DD. For LD, no statistical differences were found. CONCLUSION: This clinical retrospective study shows that immunotherapy induction was associated with improvement of outcomes, graft function, and survival in patients treated with immunotherapy in comparison with patients who did not received induction therapy. These findings strongly suggest that immunotherapy should be used for all patients transplanted with kidneys from deceased donors.

Perspectivas atuais e futuras em transplante de órgäos

Os autores abordam os principais tópicos relativos aos recentes avanços em transplantes, especialmente as novas e futuras drogas imunossupressoras, o xenotransplante e a aplicaçäao clínica das células-tronco