Effect of novel bicaval anastomosis technique for transplantation with and without prior cardiac surgery history

Background

To evaluate the graft outcomes after orthotopic heart transplantation (HTx) with a novel bicaval anastomosis technique between recipients with and without a history of prior cardiac surgery.

Methods

Of 70 patients who underwent HTx with a novel four-corners traction bicaval anastomosis technique from August 2017 to November 2019, 60 recipients underwent the HTx procedure as their first cardiac surgery (group A), while 10 recipients underwent HTx after prior cardiac surgery (group B). Patients in the two groups were compared in terms of their preoperative baseline variables such as etiological categories, history of blood transfusion and panel reactive antibody (PRA), intraoperative operation time and blood infusion volume, postoperative treatment time, and complications such as acute rejection and 30-day mortality as well as survival rates.

Results

Preoperative variables were comparable in group A and group B except for the history of blood transfusion (0% vs. 90.0%, P<0.001, respectively); the level of PRA was 7.5%±5.8% and 9.5%±10.9% for group A and B, respectively (P=0.583), but the time of the operation was nearly 1 hour longer for group B than group A (all P<0.05). No cases of left atrial thrombosis and donor heart distortion were observed in either group. Reoperation (1.7% vs. 10.0%, P=0.267), infection (0% vs. 10.0%, P=0.142), other postoperative complications as well as the 30-day mortality (1.7% vs. 10.0%, P=0.267), and postoperative survival rates (91.5% vs. 90.0%, P=0.805) were comparable between the two groups (all P>0.05).

Conclusions

Four-corner traction bicaval anastomosis combined with a continuous everting suture technique may result in approximately comparable prognoses for heart recipients with a history of cardiac surgery when compared with those without a history of cardiac surgery and this technique may reduce the incidence of left atrial thrombosis and distortion. Further follow-up of the long-term outcomes will be required to validate these results.

Relative decrease in hemoglobin and outcomes in patients undergoing kidney transplantation surgery: A retrospective cohort study

BACKGROUND

Recent surgical literature suggests that a relative decrease in hemoglobin (ΔHb) is predictive of adverse outcomes regardless of the absolute level. We aimed to examine the association between perioperative ΔHb and kidney transplantation (KT) outcomes.

METHODS

This was a retrospective cohort study of transplant recipients, where ΔHb = [Hb0- Hb1Hb0]x 100 (Hb₀ = hemoglobin pre-KT and Hb₁ = lowest hemoglobin 24-h post-KT). The main outcome of interest was immediate graft function (IGF).

RESULTS

Of the 899 eligible patients, 38% experienced IGF, and ΔHb was associated with 36% lower odds of IGF. Also, ΔHb was associated with higher all-cause graft failure and longer length of stay but not death-censored graft failure or mortality. ΔHb ≥30% was the threshold beyond which the odds of IGF were significantly lower even if Hb₁ was ≥7 g/dL.

CONCLUSION

ΔHb is associated with inferior outcomes independent of Hb_1; whether it can be used to guide transfusion practices should be explored.

Pretransplant Calculated Panel Reactive Antibody in the Absence of Donor-Specific Antibody and Kidney Allograft Survival

BACKGROUND AND OBJECTIVES

Panel reactive antibody informs the likelihood of finding an HLA-compatible donor for transplant candidates, but has historically been associated with acute rejection and allograft survival because testing methods could not exclude the presence of concomitant donor-specific antibodies. Despite new methods to exclude donor-specific antibodies, panel reactive antibody continues to be used to determine the choice of induction and maintenance immunosuppression. The study objective was to determine the clinical relevance of panel reactive antibody in the absence of donor-specific antibodies.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Retrospective observational study of kidney allograft survival among 4058 zero HLA-A-, B-, DR-, and DQB1-mismatched transplant recipients without antibodies to donor kidney antigens encoded by these HLA gene loci.

RESULTS

Among 4058 first and repeat transplant recipients, patients with calculated panel reactive antibody (cPRA) 1%-97% were not at higher risk of transplant failure, compared with patients with cPRA of 0% (death censored graft loss: hazard ratio, 1.07; 95% confidence interval, 0.82 to 1.41). Patients with cPRA ≥98% had a higher risk of graft loss from any cause including death (hazard ratio, 1.39; 95% confidence interval, 1.08 to 1.79) and death censored allograft failure (hazard ratio, 1.78; 95% confidence interval, 1.27 to 2.49). In stratified analyses, the higher risk of graft loss among patients with cPRA ≥98% was only observed among repeat, but not first, transplant recipients. In subgroup analysis, there was no association between cPRA and graft loss among living related transplant recipients.

CONCLUSIONS

Calculated panel reactive antibody is poorly associated with post-transplant immune reactivity to the allograft in the absence of donor-specific antibody.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_01_25_CJN13640820_final.mp3.

Early Posttransplant Blood Transfusion and Risk for Worse Graft Outcomes

Introduction

Blood transfusion is a risk factor for allosensitization. Nevertheless, blood transfusion posttransplant remains a common practice. We evaluated the effect of posttransplant blood transfusion on graft outcomes.

Methods

We included nonsensitized, first-time, kidney-alone recipients transplanted between 1 July 2015 and 31 December 2017. Patients were grouped based on receiving blood transfusion in the first 30 days posttransplant. The primary end point was a composite outcome of biopsy-proven acute rejection, death of any cause, or graft failure in the first year posttransplant. Secondary outcomes included the individual components of the primary outcome and the cumulative incidence of de novo donor-specific antibodies (DSAs).

Results

Two hundred seventy-three patients were included. One hundred twenty-seven (47%) received blood transfusion. Patients in the transfusion group were more likely to be older, have had a deceased donor, and have received induction with basiliximab. There was no difference between groups in the composite primary outcome (adjusted hazard ratio = [HR] 1.34; 95% confidence interval [CI], 0.83–2.17; P = 0.23). The cumulative incidence of de novo DSAs during the first year posttransplant was similar between groups (12.8% transfusion vs. 10.9% no transfusion, P = 0.48).

Conclusion

Early transfusion of blood products in kidney transplant recipients receiving induction with lymphocyte depletion was not associated with an increased hazard of experiencing acute rejection, death from any cause, or graft loss.

Heterogeneity of memory B cells

Potential solid organ transplant recipients broadly sensitized to HLA have long wait times, low transplant rates and poor outcomes. The new kidney allocation system has improved access to the most highly sensitized recipients; however, their long-term outcomes are unknown. Emerging data suggest that memory B cell repertoire is broader than the plasma cell repertoire, therefore, despite refinements in anti-HLA antibody detection technology, donor-specific HLA- specific memory B cells may in fact be present in some, if not most, highly sensitized recipients with no detectable donor-specific antibodies. In addition, new findings have underscored the heterogeneity in memory B cell generation, and in the signals that determine memory versus plasma cell fate during primary antigen encounter, as well as memory B cell differentiation upon antigen reencounter into plasma cells or reentry into germinal centers to subsequently emerge as higher affinity and class-switched plasma cells. Thus, heterogeneity memory B cells generation may affect the efficacy of specific immunomodulation during the recall response. We propose that the ability to quantify donor-specific B cell in transplant recipients is urgently required to provide insights into the mechanisms of sensitization and recall, and for the early detection of acute and chronic AMR.

Total Red Blood Cell Transfusions for Chronic Hemodialysis Patients in a Single Center, 2009-2013

BACKGROUND

Anemia management in chronic hemodialysis (HD) has been affected by the implementation of the prospective payment system (PPS) and changes in clinical guidelines. These factors could impact red blood cell (RBC) transfusion in HD patients. Our distinctive care system contains complete records for all RBC transfusions among our HD patients.

AIMS

To determine RBC transfusions in patients with prevalent chronic HD, site of administration (inpatient or outpatient), and ordering physician specialty for inpatients; compare pre- and post-PPS RBC transfusions; and compare RBC transfusions during changes in desired outpatient hemoglobin (Hb) range for patients with chronic HD.

METHODS

Retrospective analysis of medical and blood bank records for patients with prevalent chronic HD July 2009 through June 2013.

RESULTS

In total, 310-356 patients were studied. Mean (SD) units of RBCs per 100 patients per month for the study's 48 months were outpatient, 2.6 (1.5), and inpatient, 9.4 (4.6). Outpatient pre-PPS RBC units transfused were 2.1 (0.6) vs. post-PPS of 2.6 (1.5; p = 0.22, t test); for inpatients pre-PPS, 7.9 (4.5) RBC units per month vs. post-PPS, 11.5 (5.1; p = 0.11, t test). Inpatient RBC transfusions accounted for 75.2% (14.2%) of all RBC transfusions; 67.3% (16.3%) of inpatient transfusions were ordered by nonnephrologists. Changes in desired Hb range for outpatient HD patients did not lead to changes in RBC transfusions.

CONCLUSIONS

No changes in RBC transfusions occurred among our patients with chronic HD with PPS implementation and in desired Hb range during the study period. Most transfusions were given in inpatient settings by nonnephrologists.

Characterization of transfusion-elicited acute antibody-mediated rejection in a rat model of kidney transplantation

Animal models of antibody-mediated rejection (ABMR) may provide important evidence supporting proof of concept. We elicited donor-specific antibodies (DSA) by transfusion of donor blood (Brown Norway RT1(n) ) into a complete mismatch recipient (Lewis RT1(l) ) 3 weeks prior to kidney transplantation. Sensitized recipients had increased anti-donor splenocyte IgG1, IgG2b and IgG2c DSA 1 week after transplantation. Histopathology was consistent with ABMR characterized by diffuse peritubular capillary C4d and moderate microvascular inflammation with peritubular capillaritis + glomerulitis > 2. Immunofluorescence studies of kidney allograft tissue demonstrated a greater CD68/CD3 ratio in sensitized animals, primarily of the M1 (pro-inflammatory) phenotype, consistent with cytokine gene analyses that demonstrated a predominant T helper (TH )1 (interferon-γ, IL-2) profile. Immunoblot analyses confirmed the activation of the M1 macrophage phenotype as interferon regulatory factor 5, inducible nitric oxide synthase and phagocytic NADPH oxidase 2 were significantly up-regulated. Clinical biopsy samples in sensitized patients with acute ABMR confirmed the dominance of M1 macrophage phenotype in humans. Despite the absence of tubulitis, we were unable to exclude the effects of T cell-mediated rejection. These studies suggest that M1 macrophages and TH 1 cytokines play an important role in the pathogenesis of acute mixed rejection in sensitized allograft recipients.

Anemia management trends in hospital-based dialysis centers (HBDCs), 2010 to 2013

BACKGROUND

Few data have been reported on anemia management practices in hospital-based dialysis centers (HBDCs), which are uniquely different from other freestanding dialysis centers. Examining data from HBDCs would help determine if HBDCs and the general US dialysis population have similar trends related to how anemia is managed in dialysis patients.

OBJECTIVE

Given recent changes in the prescribing information of erythropoiesis-stimulating agents (ESAs) and in end-stage renal disease-related health policy and reimbursement, this study describes trends in anemia management practices in HBDCs from January 2010 through March 2013.

METHODS

Electronic medical records of 5404 adult hemodialysis patients in 50 US-based HBDCs were analyzed retrospectively. Patients included in the study cohort were aged ≥18 years and had at least 1 hemoglobin (Hb) measurement and 1 dose of an ESA between January 2010 and March 2013. End points included Hb concentration, darbepoetin alfa dosing, epoetin alfa dosing, and iron biomarkers (transferrin saturation and ferritin) and dosing.

RESULTS

From 2010 to 2013, mean monthly Hb levels declined from 11.4 to 10.7 g/dL; the percentage of patients with mean monthly Hb levels <10 g/dL increased from 11.3% to 24.4%; and the percentage of patients with mean monthly Hb levels >12 g/dL declined from 30.1% to 11.2%. The median darbepoetin alfa cumulative 4-week dose also declined 38.8%, and the weekly epoetin alfa dose declined 24%. From January 2010 to March 2013, the percentage of patients with transferrin saturation >30% increased from 35.8% to 43.6%, the percentage of patients with ferritin levels >500 ng/mL increased from 62.0% to 77.9%, the percentage of patients with ferritin levels ≥800 ng/mL increased from 28.9% to 47.3%, and the median cumulative 4-week intravenous iron dose increased 50%.

CONCLUSIONS

These study results support growing evidence that meaningful changes have occurred over the last 3 years in how anemia is clinically managed in US hemodialysis patients. Study limitations include that changes in patient clinical/demographic characteristics over time were not controlled for and that study findings may not be applicable to HBDCs that have different patient populations and/or do not use an electronic medical record system. Continuing to evaluate anemia management practices in HBDCs would provide additional information on the risks and benefits of anemia care. Consistent with national data, the findings from this study indicate that from 2010 to 2013, HBDCs modified anemia management practices for dialysis patients, as evidenced by reductions in mean monthly Hb levels and ESA dosing and by increases in iron biomarkers and dosing.

Effect of facility-level hemoglobin concentration on dialysis patient risk of transfusion

BACKGROUND

Changes in anemia management practices due to concerns about erythropoiesis-stimulating agent safety and Medicare payment changes may increase patient risk of transfusion. We examined anemia management trends in hemodialysis patients and risk of red blood cell (RBC) transfusion according to dialysis facility-level hemoglobin concentration.

STUDY DESIGN

Retrospective follow-up study; 6-month study period (January to June), 3-month exposure/follow-up.

SETTING & PARTICIPANTS

For each year in 2007-2011, annual cohorts of point-prevalent Medicare primary payer patients receiving hemodialysis on January 1 with one or more hemoglobin measurements during the study period. Annual cohorts averaged 170,000 patients, with 130,000 patients and 3,100 facilities for the risk analysis.

PREDICTOR

Percentage of facility patient-months with hemoglobin level<10 g/dL.

OUTCOME

Patient-level RBC transfusion rates.

MEASUREMENTS

Monthly epoetin alfa and intravenous iron doses, mean hemoglobin levels, and RBC transfusion rates; percentage of facility patient-months with hemoglobin levels<10 g/dL (exposure) and patient-level RBC transfusion rates (follow-up).

RESULTS

Percentages of patients with hemoglobin levels<10 g/dL increased every year from 2007 (6%) to 2011 (~11%). Epoetin alfa doses, iron doses, and transfusion rates remained relatively stable through 2010 and changed in 2011. Median monthly epoetin alfa and iron doses decreased 25% and 43.8%, respectively, and monthly transfusion rates increased from 2.8% to 3.2% in 2011, a 14.3% increase. Patients in facilities with the highest prevalence of hemoglobin levels<10 g/dL over 3 months were at ~30% elevated risk of receiving RBC transfusions within the next 3 months (relative risk, 1.28; 95% CI, 1.22-1.34).

LIMITATIONS

Possibly incomplete claims data; smaller units excluded; hemoglobin levels reported monthly for patients receiving epoetin alfa; transfusions usually not administered in dialysis units.

CONCLUSIONS

Dialysis facility treatment practices, as assessed by percentage of patient-months with hemoglobin levels<10 g/dL over 3 months, were associated significantly with risk of transfusions in the next 3 months for all patients in the facility, regardless of patient case-mix.

Sensitization from transfusion in patients awaiting primary kidney transplant

BACKGROUND

Sensitization to human leukocyte antigen (HLA) from red blood cell (RBC) transfusion is poorly quantified and is based on outdated, insensitive methods. The objective was to evaluate the effect of transfusion on the breadth, magnitude and specificity of HLA antibody formation using sensitive and specific methods.

METHODS

Transfusion, demographic and clinical data from the US Renal Data System were obtained for patients on dialysis awaiting primary kidney transplant who had ≥ 2 HLA antibody measurements using the Luminex single-antigen bead assay. One cohort included patients with a transfusion (n = 50) between two antibody measurements matched with up to four nontransfused patients (n = 155) by age, sex, race and vintage (time on dialysis). A second crossover cohort (n = 25) included patients with multiple antibody measurements before and after transfusion. We studied changes in HLA antibody mean fluorescence intensity (MFI) and calculated panel reactive antibody (cPRA).

RESULTS

In the matched cohort, 10 of 50 (20%) transfused versus 6 of 155 (4%) nontransfused patients had a ≥ 10 HLA antibodies increase of >3000 MFI (P = 0.0006); 6 of 50 (12%) transfused patients had a ≥ 30 antibodies increase (P = 0.0007). In the crossover cohort, the number of HLA antibodies increasing >1000 and >3000 MFI was higher in the transfused versus the control period, P = 0.03 and P = 0.008, respectively. Using a ≥ 3000 MFI threshold, cPRA significantly increased in both matched (P = 0.01) and crossover (P = 0.002) transfused patients.

CONCLUSIONS

Among prospective primary kidney transplant recipients, RBC transfusion results in clinically significant increases in HLA antibody strength and breadth, which adversely affect the opportunity for future transplant.

Red blood cell transfusion use in patients with chronic kidney disease

BACKGROUND

There is limited data available on the use of red blood cell (RBC) transfusions in younger chronic kidney disease patients not on dialysis (CKD-ND), for whom the consequences of developing antibodies to foreign antigens (allosensitization) may be particularly relevant.

METHODS

We used the Ingenix medical claims database, comprising data on ∼40 million commercially insured US individuals, to identify annual (2002-08) cohorts of patients 18-64 years of age with newly diagnosed CKD. We followed each cohort for 1 year to estimate RBC transfusion rates and used Cox proportional hazards regression to identify patient characteristics associated with time to first transfusion.

RESULTS

We identified 120 790 newly diagnosed CKD patients for the years 2002-08; 54% were 50-64 years of age. Overall, the transfusion rate was 2.64/100 person-years (PYs) (95% CI: 2.52-2.77). Rates were higher among those with diagnosed anemia [9.80/100 PYs (95% CI: 9.31-10.3)] and among those who progressed to end-stage renal disease (ESRD) [28.0/100 PYs (95% CI: 23.7-33.0)]. For those progressing to ESRD, transfusion rates more than doubled between 2002 and 2008. Of the factors evaluated, transfusion history and the presence of heart failure and diabetes were most strongly associated with a receipt of a transfusion.

CONCLUSIONS

RBC transfusions are relatively common and on the rise among younger CKD-ND patients who are anemic and progress to ESRD. Efforts to decrease the use of transfusions may be important for potential transplant candidates who progress to ESRD.

The DOPPS Practice Monitor for US dialysis care: trends through August 2011

We have examined trends in hemodialysis practice from August 2010 to August 2011, a time frame spanning the implementation of the bundled PPS, a major ESA label change by the FDA, and announcements from CMS on the proposed and final rules for the first year of the Quality Incentive Program (QIP) plus the proposed rules for the second and third years of the QIP. Although many hemodialysis practices have remained stable during this 1-year time period, substantial changes have been seen. These include a decline in epoetin dose and hemoglobin levels, an increase in IV iron use and serum ferritin levels, and an increase in PTH levels. The rates of decline in hemoglobin and epoetin dosing levels were greatest in the 2 months after the ESA label change in June 2011. Trends in anemia care in ensuing months, with more follow-up time after the label change, will be of great interest. In view of declining hemoglobin levels, a mechanism for comprehensive monitoring of transfusion rates is warranted to understand this important aspect of care for hemodialysis patients. Regarding clinical outcomes, no trend in all-cause mortality has been evident during this 1-year time period. Additional follow-up is warranted to understand if findings reported here persist over time, and require confirmation with national data as these become available. Trends in clinical care may not necessarily affect patient outcomes, and careful evaluation is required to understand effects on patient outcomes.