A Multinational Cohort Study Examining Sex Differences in Excess Risk of Death With Graft Function After Kidney Transplant.

BACKGROUND: Kidney transplant recipients show sex differences in excess overall mortality risk that vary by donor sex and recipient age. However, whether the excess risk of death with graft function (DWGF) differs by recipient sex is unknown. METHODS: In this study, we combined data from 3 of the largest transplant registries worldwide (Scientific Registry of Transplant Recipient, Australia and New Zealand Dialysis and Transplant Registry, and Collaborative Transplant Study) using individual patient data meta-analysis to compare the excess risk of DWGF between male and female recipients of a first deceased donor kidney transplant (1988-2019), conditional on donor sex and recipient age. RESULTS: Among 463 895 individuals examined, when the donor was male, female recipients aged 0 to 12 y experienced a higher excess risk of DWGF than male recipients (relative excess risk 1.68; 95% confidence interval, 1.24-2.29); there were no significant differences in other age intervals or at any age when the donor was female. There was no statistically significant between-cohort heterogeneity. CONCLUSIONS: Given the lack of sex differences in the excess risk of DWGF (other than in prepubertal recipients of a male donor kidney) and the known greater excess overall mortality risk for female recipients compared with male recipients in the setting of a male donor, future study is required to characterize potential sex-specific causes of death after graft loss.

COVID-19 Status, Symptom Burden, and Characteristics of Dialysis Patients Residing in Areas of Community Transmission: Research Letter.

BACKGROUND: Routine testing of hemodialysis patients for COVID-19 (outside of those identified as "at risk" based on regional practice) is not universally recommended. However, there is variability in the clinical presentation of COVID-19; patients may experience symptoms that do not meet regional criteria for testing and some patients with active infection may be asymptomatic. To avoid missing individuals who are infected, consideration could be made for regular screening, particularly among those residing in areas with evidence of community spread. OBJECTIVE: To describe the clinical characteristics, symptom burden, and COVID-19 status in a cross-section of hemodialysis patients residing in areas with evidence of community spread. DESIGN: Cross-sectional study. SETTING: Three hemodialysis units in a large tertiary care facility in Nova Scotia, Canada. PATIENTS: In-center hemodialysis patients who resided in areas with evidence of community transmission at the time of the study. METHODS: All dialysis patients (irrespective of whether or not they resided in areas with community spread) completed a standard "at-risk" questionnaire for COVID-19 based on (1) 2 or more of new or worsening cough, fever greater than 38°C, sore throat, headache, runny nose/new or acute respiratory illness consistent with infection or (2) any one of close contact with a known/suspected case, travel outside of the province or residence in a facility with an outbreak prior to entry into the dialysis unit at each treatment. Patients residing in areas with evidence of community spread were swabbed for SARS-CoV-2 over a 1-week period (May 1-7, 2020) using a combined oropharyngeal/nares swab irrespective of whether or not they were identified as "at-risk." MEASUREMENTS: Baseline characteristics of patients were acquired using electronic records. In addition to the "at-risk" questionnaire, patients answered "yes" or "no" to any of the following symptoms at the time of the swab (sneeze, fatigue, myalgia, nausea/vomiting, diarrhea, malaise, abdominal pain, loss of taste, and loss of smell). RESULTS: Of the 334 patients receiving dialysis at the time of the study, 133 resided in areas with evidence of community transmission and 104 consented for the study. No patients met our regional criteria for being "at-risk" and no patients reported cough, sore throat or fever at the time of swab. Many other symptoms were noted, including sneezing (24%), fatigue (16%), myalgias (11%), nausea/vomiting (11%), loss of taste (4%), and loss of smell (4%). Overall, 100% of swabs performed for this study were negative for SARS-CoV-2. LIMITATIONS: Single-center study, and the daily new case rate was exceedingly low (4-14) at the time of the study, emphasizing that the findings are not generalizable to areas of higher prevalence of SARS-CoV-2. CONCLUSIONS: In this study of hemodialysis patients residing in areas with community spread who otherwise did not meet symptom criteria for being "at-risk," we did not identify any individual who tested positive for SARS-CoV-2. Future studies are needed to examine the utility of routine testing for COVID-19 (outside of those who are "at-risk") in areas of higher disease prevalence. TRIAL REGISTRATION: Not applicable as this is not a clinical trial.

Nonimmunologic Donor-Recipient Pairing, HLA Matching, and Graft Loss in Deceased Donor Kidney Transplantation.

BACKGROUND: In kidney transplantation, nonimmunologic donor-recipient (D-R) pairing is generally not given the same consideration as immunologic matching. The aim of this study was to determine how nonimmunologic D-R pairing relates to independent donor and recipient factors, and to immunologic HLA match for predicting graft loss. METHODS: Seven D-R pairings (race, sex, age, weight, height, cytomegalovirus serostatus, and HLA match) were assessed for their association with the composite outcome of death or kidney graft loss using a Cox regression-based forward stepwise selection model. The best model for predicting graft loss (including nonimmunologic D-R pairings, independent D-R factors, and/or HLA match status) was determined using the Akaike Information Criterion. RESULTS: Twenty three thousand two hundred sixty two (29.9%) people in the derivation data set and 9892 (29.7%) in the validation data set developed the composite outcome of death or graft loss. A model that included both independent and D-R pairing variables best predicted graft loss. The c-indices for the derivation and validation models were 0.626 and 0.629, respectively. Size mismatch (MM) between donor and recipient (>30 kg [D < R} and >15 cm [D < R]) was associated with poor patient and graft survival even with 0 HLA MM, and conversely, an optimal D-R size pairing mitigated the risk of graft loss seen with 6 HLA MM. CONCLUSIONS: D-R pairing is valuable in predicting patient and graft outcomes after kidney transplant. D-R size matching could offset the benefit and harm seen with 0 and 6 HLA MM, respectively. This is a novel finding.

The Use of Donation After Circulatory Death Organs for Simultaneous Liver-kidney Transplant: To DCD or Not to DCD?

BACKGROUND: Because of the challenges with organ scarcity, many centers performing simultaneous liver-kidney transplant (SLKT) are opting to accept donation after circulatory death (DCD) organs as a means of facilitating earlier transplant and reducing death rates on the waitlist. It has been suggested, however, that DCD organs may have inferior graft and patient survival posttransplant compared with donation after neurologic death (DND) organs. METHODS: We created a Markov model to compare the overall outcomes of accepting a DCD SLKT now versus waiting for a DND SLKT in patients waitlisted for SLKT, stratified by base Model for End-Stage Liver Disease (MELD) score (≤20, 21-30, >30). RESULTS: Waiting for DND SLKT was the preferred treatment strategy for patients with a MELD score of 30 or less (incremental value of 0.54 and 0.36 quality-adjusted life years for MELD score of 20 or less and MELD score of 21 to 30 with DND versus DCD SLKT, respectively). The option to accept a DCD SLKT became the preferred choice for those with a MELD score greater than 30 (incremental value of 0.31 quality-adjusted life years for DCD versus DND SLKT). This finding was confirmed in a probabilistic sensitivity analysis and persisted when analyzing total life years obtained for accept DCD versus do not accept DCD. CONCLUSIONS: There is a benefit to accepting DCD SLKT for patients with MELD score greater than 30. Although not accepting DCD SLKT and waiting for DND SLKT is the preferred option for patients with MELD of 30 or less, the incremental value is small.