Bruminhent, Jackrapong

Background: Black kidney transplant recipients have worse allograft outcomes compared to White recipients. The feature importance and feature interaction network analysis framework of machine learning random forest (RF) analysis may provide an understanding of RF structures to design strategies to prevent acute rejection among Black recipients. Methods: We conducted tree-based RF feature importance of Black kidney transplant recipients in United States from 2015 to 2019 in the UNOS database using the number of nodes, accuracy decrease, gini decrease, times_a_root, p value, and mean minimal depth. Feature interaction analysis was also performed to evaluate the most frequent occurrences in the RF classification run between correlated and uncorrelated pairs. Results: A total of 22,687 Black kidney transplant recipients were eligible for analysis. Of these, 1330 (6%) had acute rejection within 1 year after kidney transplant. Important variables in the RF models for acute rejection among Black kidney transplant recipients included recipient age, ESKD etiology, PRA, cold ischemia time, donor age, HLA DR mismatch, BMI, serum albumin, degree of HLA mismatch, education level, and dialysis duration. The three most frequent interactions consisted of two numerical variables, including recipient age:donor age, recipient age:serum albumin, and recipient age:BMI, respectively. Conclusions: The application of tree-based RF feature importance and feature interaction network analysis framework identified recipient age, ESKD etiology, PRA, cold ischemia time, donor age, HLA DR mismatch, BMI, serum albumin, degree of HLA mismatch, education level, and dialysis duration as important variables in the RF models for acute rejection among Black kidney transplant recipients in the United States.

AbstractBackgroundHigh plasma cytomegalovirus (CMV) DNA load is generally associated with CMV tissue‐invasive disease in solid organ transplant recipients. However, some tissue‐invasive diseases, especially CMV gastrointestinal (GI) disease, have undetectable to very low plasma CMV DNA loads. Highly sensitive nucleic acid amplification testing (NAAT) has been increasingly used to quantify low‐level CMV DNA loads. Our primary objective was to investigate the epidemiology of CMV GI disease and evaluate the validity of plasma CMV NAAT for the diagnosis of CMV GI disease in kidney transplant (KT) recipients.MethodsWe conducted a retrospective study of all KT recipients who developed CMV GI disease from January 2016 to December 2018. Plasma CMV DNA load was measured using real‐time PCR. The cut‐off value of plasma CMV DNA load for diagnosing and risk factors of CMV GI disease were analyzed.ResultsA total 17 (3.4%) cases of CMV GI disease occurred in 494 KT recipients. Fifteen (88%) patients had CMV D + /R + serostatus. Fourteen (82%) patients developed CMV GI disease within 6 months after KT. Plasma CMV DNA loads were detectable in all (100%) patients with a median load 11,102 (IQR 2,935‐107,160) IU/ml. A plasma CMV DNA load of 4,063 IU/ml was established as al cut‐off for diagnosing CMV GI disease (AUC 0.74, sensitivity 76.5%, specificity 70%, PPV 68, NPV 78). In multivariate analysis, prolonged cold ischemic time (HR 1.14, 95% CI 1.05‐1.23, P = .002) and CMV D + /R ‐ serostatus (HR 9.31, 95% CI 2.12‐40.74, P = .003) were associated with CMV GI disease.ConclusionsUsing highly sensitive NAAT could potentially assist in the diagnosis of CMV GI disease in a CMV D + /R + serostatus setting. KT recipients with CMV seromismatch and prolonged cold ischemic time are at higher risk of CMV GI disease.

Abstract Background Clostridium difficile is a major cause of diarrhea in thoracic organ transplant recipients. We investigated the epidemiology, risk factors, and outcome of Clostridium difficile infection ( CDI ) in heart and heart‐lung transplant ( HT ) recipients. Methods This is a retrospective study from 2004 to 2013. CDI was defined by diarrhea and a positive toxigenic C. difficile in stool measured by toxin enzyme immunoassay (2004‐2006) or polymerase chain reaction (2007‐2013). Cox proportional hazards regression was used to model the association of risk factors with time to CDI and survival with CDI following transplantation. Results There were 254 HT recipients, with a median age of 53 years ( IQR , 45‐60); 34% were female. During the median follow‐up of 3.1 years ( IQR , 1.3‐6.1), 22 (8.7%) patients developed CDI . In multivariable analysis, risk factors for CDI were combined heart‐lung transplant ( HR 4.70; 95% CI , 1.30‐17.01 [ P =.02]) and retransplantation ( HR 7.19; 95% CI , 1.61‐32.12 [ P =.01]). Acute cellular rejection was associated with a lower risk of CDI ( HR 0.34; 95% CI , 0.11‐0.94 [ P =.04]). CDI was found to be an independent risk factor for mortality ( HR 7.66; 95% CI , 3.41‐17.21 [ P <.0001]). Conclusions Clostridium difficile infection after HT is more common among patients with combined heart‐lung and those undergoing retransplantation. CDI was associated with a higher risk of mortality in HT recipients.

Despite preexisting cytomegalovirus (CMV) immunity, CMV‐seropositive liver transplantation (LT) patients remain at risk of CMV infection. We hypothesized that the pre‐transplant CMV antibody titer correlates with the risk of CMV reactivation. We conducted a retrospective study of CMV‐seropositive LT recipients who did not receive anti‐CMV prophylaxis from 2007 to 2013. The pre‐transplant CMV immunoglobulin G (IgG) titer, which was measured with an enzyme‐linked fluorescent immunoassay, was assessed as a risk factor for CMV reactivation with multivariate Cox proportional hazards models. The population consisted of 225 CMV‐seropositive LT patients with a median age of 57 years (interquartile range, 47‐62 years). The CMV titer distributions were as follows: <60 (40%) and ≥60 AU/mL (60%). The Kaplan‐Meier estimates for CMV infection were 17% at 3 months, 18% at 6 months, and 19% at 12 months after transplantation. In a univariate analysis, a marginally significant increased risk of CMV infection was seen in LT recipients with a pre‐transplant CMV IgG titer < 60 AU/mL versus ≥ 60 AU/mL [hazard ratio (HR), 1.79; 95% confidence interval (CI), 0.98‐3.28 (P =0.06)]. This risk was statistically significant in the subgroup of recipients who received allografts from CMV‐seropositive donors [HR, 2.21; 95% CI, 1.15‐4.26 (P =0.02)]. In a multivariate analysis, a pre‐transplant CMV IgG titer < 60 AU/mL was significantly associated with CMV infection [HR, 3.11; 95% CI, 1.60‐6.03 (P < 0.001)]. The other risk factors were high body mass index, donor CMV seropositivity, prolonged cold ischemic time, use of an interleukin‐2 receptor antagonist for induction therapy, and high numbers of post‐transplant infections. A lower pre‐transplant CMV antibody titer is significantly associated with CMV infection after LT. Quantitative measurement of CMV‐specific humoral immunity may have a potential role in improving the CMV prevention strategy in CMV‐seropositive LT recipients.Liver Transpl 21:539–546, 2015. © 2015 AASLD.

AbstractWe report a 65‐year‐old heart transplant recipient who presented with conjunctivitis, likely acquired from a family member who worked at a daycare center during an outbreak of conjunctivitis. He developed a severe adenoviral pneumonitis, which was successfully treated with intravenous cidofovir combined with a reduction of immunosuppression.