Large volume plasmapheresis using a single-use immunoadsorption column: A cost-effective approach for desensitization in ABO-incompatible liver transplant.

INTRODUCTION: Liver transplant is a life-saving treatment, but due to the limited availability of suitable liver donors, ABO-incompatible liver transplants (ABOi-LT) are conducted to increase the availability of liver donors. Perioperative desensitization for ABOi-LT is an established strategy to circumvent the risk of graft rejection. A single prolonged session can be performed to achieve the desired titers to avoid using multiple immunoadsorption (IA) columns or off-label reuse of single-use columns. This study retrospectively assessed the effectiveness of a single prolonged plasmapheresis session using IA as a desensitization strategy in live donor liver transplant (LDLT). MATERIALS AND METHODS: This retrospective observational study conducted at a center for liver diseases in North India on six ABOi-LDLT patients who underwent single prolonged IA sessions in the perioperative period from January 2018 to June 2021. RESULTS: Median baseline titer in patients was 320 (64, 1024). The median plasma volume adsorbed was 7.5 volumes (4, 8) per procedure, with a mean procedure time of 600 min (310-753). The reduction in titer ranged from 4 log to 7 log reduction per procedure. Two patients developed transient hypotension during the procedure, which was managed successfully. The median duration of pre-transplant hospital stay was 1.5 days (1, 3). CONCLUSION: Desensitization therapy helps overcome the ABO barrier and decreases the waiting period before a transplant when ABO identical donors are unavailable. A single prolonged IA session reduces the cost of additional IA columns and hospital stay, thus making it a cost-effective approach to desensitization.

Successful treatment of pure red cell aplasia using therapeutic plasma exchange after ABO-incompatible hematopoietic stem cell transplant.

Hematopoietic stem cell transplants (HSCTs) are widely used in the treatment of hematologic malignancies and bone marrow failure syndromes. ABO compatibility is typically of secondary importance, and up to 50% of HSCT are performed in ABO-incompatible pairings. In the literature, pure red cell aplasia (PRCA) occurs in 1% to 50% of all major/bidirectional ABO-incompatible stem cell transplants, but treatment of PRCA remains heterogeneous. Here, we report two cases in which patients with transfusion-dependent PRCA following HSCT were successfully treated with therapeutic plasma exchange (TPE). Case 1: A 52-year-old type O-positive male with acute myeloid leukemia underwent HSCT using apheresis-derived HSCs from a fully human leukocyte antigen (HLA)-matched, related type A-positive male donor. He developed PRCA that was refractory to multiple therapies, so a series of 10 TPE was performed over 3 weeks. Case 2: A 21-year-old type A-positive male with aplastic anemia underwent HSCT using bone marrow-derived HSCs from a fully HLA-matched related type B-positive female donor. He developed PRCA that was refractory to multiple therapies, so a series of 5 TPE was performed over 2 weeks. Case 1: The patient has been transfusion independent since TPE #7, and type A red blood cells (RBCs) were seen on the ABO type after TPE #9. Case 2: The patient has been transfusion independent since after TPE #1, and type B RBCs were seen on the ABO type after TPE #5. TPE was successful in treating two patients with PRCA after ABO-incompatible HSCT transplants. Isoagglutinin titers decreased below the level of detection for both our patients. Ultimately both patients became transfusion independent and showed evidence of erythroid cell recovery.

Clinical consequences of the extremely rare anti-PP1Pk isoantibodies in pregnancy: a case series and review of the literature.

BACKGROUND: The absence of the red cell antigens P, P1 and Pk , known as 'p', represents an extremely rare red cell phenotype. Individuals with this phenotype spontaneously form anti-PP1Pk isoantibodies, associated with severe haemolytic transfusion reactions, recurrent spontaneous abortion and haemolytic disease of the fetus and newborn (HDFN). METHODS: We report a series of four successful pregnancies in three women with anti-PP1Pk isoantibodies, one complicated by HDFN, another by intrauterine growth restriction, all managed supportively. We also review the literature regarding the management of pregnancy involving anti-PP1Pk isoimmunization. RESULTS: The literature surrounding anti-PP1Pk in pregnancy is limited to a very small number of case reports. The majority report management with therapeutic plasma exchange (TPE) with or without intravenous immunoglobulin. The relationship between titre and risk of pregnancy loss remains unclear, though a history of recurrent pregnancy loss appears important. Although a positive cord blood direct antiglobulin test is frequently noted, clinically significant HDFN appears uncommon, though possible. CONCLUSION: Early initiation of TPE in high risk patients should be strongly considered. If possible, pregnancies should be managed in a high-risk obstetric or maternal fetal medicine service. The fetus should be monitored closely with interval fetal ultrasound and middle cerebral artery peak systolic volume Doppler to screen for fetal anaemia. Timely sourcing of compatible blood products is likely to be highly challenging, and both directed and autologous donation should be contemplated where appropriate. The International Red Cell Donor Panel may also provide access to compatible products.

Selective ABO immunoadsorption in hematopoietic stem cell transplantation with major ABO incompatibility.

OBJECTIVE: ABO mismatch between donor and recipient occurs in 40% of allogeneic hematopoietic stem cell transplantations (HCT). Different strategies have been described to reduce isohemagglutinins (IHA) before HCT. We describe the effect of selective ABO immunoadsorption (ABO IA) on erythrocyte transfusion rate and the development of post-transplant pure red cell aplasia (ptPRCA). METHODS: 63 patients with major ABO incompatibility were retrospectively analyzed. Nine patients with major ABO incompatibility and high-IHA titer were treated by ABO IA before HCT. We analyzed the need for transfusion and the occurrence of ptPRCA. We compared the outcome with patients treated by other methods to reduce IHA. RESULTS: In all nine patients treated by ABO IA, IHA decreased in a median four times. PtPRCA occurred in one patient. The median number of transfusions was 8 (range: 0-36) between d0 and d100. In 25 patients with high-IHA titer without treatment or treated by other methods to reduce IHA, the need for transfusions was comparable. No difference in the incidence of ptPRCA was observed. CONCLUSIONS: Selective ABO IA is a feasible, safe, and effective method to reduce IHA before HCT in major ABO incompatibility. No effect on transfusion rate or ptPRCA compared to other strategies could be observed.

Feasibility of Immunoadsorption plasmapheresis in an infant for ABO-incompatible solid organ transplant-A reality.

BACKGROUND: Immunoadsorption (IA) plasmapheresis is standard modality for pretransplant desensitization in ABO-incompatible solid organ transplants though technically challenging when considered for an infant or a child less than 10 kg due to non-availability of pediatric immunoadsorption (IA) columns. The major challenge is to maintain hemodynamic stability considering the large extracorporeal circuit volume meant for adults. To our best knowledge after extensive search in acclaimed global medical journals, this is the first successful attempt in an underweight (6 kg) infant of less than 1 year of age using adult size IA Column thus making it a reality. CASE CHARACTERISTICS: We report an 8-month-old male infant (A positive) of 6 kg with decompensated liver disease secondary to extrahepatic biliary atresia requiring urgent live donor liver transplantation with AB positive donor with significantly elevated pretransplant anti-B IgG/ IgM antibody titers >1:1024. Baby underwent multiple sessions of anti-B immunoadsorption plasmapheresis to lower anti-B IgM / IgG titers using available adult anti-B immunoadsorption column. Postprocedure, the antibody titers reduced to 1:8 (anti-IgG) 1:16 (anti-IgM) followed by successful ABO-incompatible live donor liver transplant (LDLT). OUTCOME: Anti-B titers remained in normal range in the immediate and post-transplant period with satisfactory liver functions and no rejection. CONCLUSION: Immunoadsorption plasmapheresis for ABO-incompatible solid organ transplantation in infants gives desirable results and can be offered to small sized infants using currently available adult sized IA columns when conducted with adequate technical expertise.

Evaluation of safety of using incompatible plasma for therapeutic plasma exchange during shortage of AB plasma.

BACKGROUND: Criteria for selection of FFP blood type has not been clearly established and use of group AB plasma is preferred by numerous transplantation protocols. AIMS: This study assesses the safety and efficacy of alternative group A or B plasma in ABO incompatible solid organ transplantation. MATERIALS & METHODS: Alternative use of group A or B plasma (incompatible plasma) was inevitable during the shortage of group AB plasma. Experience from select number of patients during the period of extreme group AB plasma shortage is described. RESULTS: The result of alternative use of group A or B plasma was within expectation, showing effective reduction of isoagglutinin titers for pre-operative desensitization and efficacy for treatment of post-operative patients. No immediate hemolytic transfusion reaction was reported. DISCUSSION: While validation in a larger cohort of patients is necessary, our limited experience have shown satisfactory clinical outcomes without adverse events. CONCLUSIONS: Use of incompatible group A or B plasma is a viable option when group AB plasma is limited.

ABO-incompatible pediatric kidney transplantation without antibody removal.

BACKGROUND: Because of the severe shortage of suitable deceased donors, ABO-incompatible living donor kidney transplantation (ABOi LDKT) is performed even in pediatric recipients in Japan. We performed pediatric ABOi LDKT using rituximab without anti-A/B antibody removal. METHODS: Thirteen pediatric recipients (mean age 7.4, range 3.4-15.7, four females) whose baseline anti-A/B IgG titers were ≤ × 64 underwent ABOi LDKT without antibody removal and splenectomy between July 2013 and April 2017 at Toho University. Mycophenolate mofetil (MMF) was initiated on day - 10. Rituximab (100 mg) was administered twice. Basiliximab and triple maintenance immunosuppression (calcineurin inhibitor, MMF, and steroids) were administered. Protocol biopsy was performed at 3 months and 1 year after transplantation. We retrospectively compared the clinical outcomes between these recipients and 37 children (mean age 9.0, range 2.6-18.9, 15 female) who underwent ABO-compatible (ABOc) LDKT during the same period. RESULTS: The mean follow-up periods of ABOi and ABOc groups were 31.9 ± 13.5 and 28.8 ± 14.4 months, respectively. In the ABOi group, no clinical acute rejection (AR) was noted and subclinical AR was observed in four patients without evidence of acute antibody-mediated rejection. In the ABOc group, clinical and subclinical AR developed in 3 and 10 patients, respectively. No significant difference was identified for the mean eGFR between the ABOi and ABOc groups (98.3 ± 48.8 vs. 86.9 ± 39.4, P = 0.452 at 3 months; 78.2 ± 21.2 vs. 79.7 ± 21.3, at 1 year, P = 0.830). Death-censored graft survival at follow-up was 100% in the ABOi group and 94.6% in the ABOc group. Patient survival during the follow-up period in both the groups was 100%. Late-onset neutropenia (LON) requiring granulocyte colony-stimulating factor occurred more frequently in the ABOi group than in the ABOc group (4 vs. 0 patients) (P < 0.001). CONCLUSIONS: Pre- and post-transplantation antibody removal is not a prerequisite for successful pediatric ABOi LDKT, at least in patients with a low anti-A/B IgG antibody titer. However, LON caused by rituximab should be monitored.

Massive transfusion associated with a hemolytic transfusion reaction: necessary precautions for prevention.

CASE REPORT: A 45-year-old male presented in severe hypovolemic shock after a thoracoabdominal gunshot wound. The massive transfusion protocol (MTP) was activated and the patient was taken to the operating room. His major injuries included liver, small bowel, and right common iliac vein. Hemorrhage was stopped and a damage control laparotomy was completed. He received a total of 113 blood products. During his postoperative course he received a group B blood transfusion on Hospital Days 2 and 7 based on incorrect blood typing late in his massive transfusion and repeat testing on Day 4. RESULTS: He succumbed to multiple organ failure on Day 8. MTPs are standard in most trauma centers during which universal donor red blood cells are initially used. As hemorrhage is controlled, the patient undergoes a complete type and cross according to blood banking protocols. These typing results are used to continue transfusions once the MTP is no longer needed. In contacting other blood banks servicing Level I trauma centers, the policy of when to switch from universal donor blood to crossmatched blood is variable. CONCLUSION: Our case illustrates a potential blood typing problem that had a disastrous outcome. We identified changes in policy that will make MTPs safer.

Prevention of hemolytic transfusion reactions with intravenous immunoglobulin prophylaxis in U- patients with anti-U.

BACKGROUND: The U- phenotype is extremely rare and is found predominantly in black African populations at a frequency of between 0.2 and 1.7%. In European populations, U- units are therefore rare, with limited availability in the United Kingdom. Anti-U is clinically significant and is known to cause hemolytic transfusion reactions (HTRs) and hemolytic disease of the fetus and newborn. It has been suggested that intravenous immunoglobulin (IVIG) may be considered as an option among supportive therapy for urgent transfusion when clinically significant antigen-matched units are not available. We report three cases with anti-U transfused with least-incompatible RBC units, their outcomes, and their clinical management. STUDY DESIGN AND METHODS: Intravenous immunoglobulin was prescribed when least-incompatible units must be issued in patients with anti-U to ameliorate acute HTR and prevent the development of delayed HTR. We report the outcome of these cases. RESULTS: Of the case reports described, one patient with weak anti-U developed a delayed HTR after transfusion with incompatible units due to an anamnestic response. Two additional patients are described, with the use of IVIG as a precautionary measure to prevent the development of HTRs when transfused with antigen-positive incompatible units. No acute HTRs or delayed HTRs were noted upon follow-up. CONCLUSION: U- units are not always readily available and transfusion support requires close collaborative working among a multidisciplinary team. Transfusion with antigen-positive incompatible units with IVIG cover both ameliorates acute HTRs and prevents the development of delayed HTRs.

Severe ABO Hemolytic Disease of the Newborn Requiring Exchange Transfusion.

ABO incompatibility (ABOi), the most common cause of hemolytic disease of the newborn (HDN), is nearly always mild and treatable with phototherapy. Reports of ABOi HDN requiring neonatal exchange transfusion are extremely rare since the inception of modern guidelines. Here, a case of ABOi HDN clearly met criteria for exchange transfusion. An O-positive African American mother delivered a B-positive neonate that quickly developed hyperbilirubinemia. The neonatal DAT was positive from anti-B and anti-A,B, and maternal IgG titer was 1024. Double volume exchange transfusion resulted in a favorable outcome. Given early discharge of newborns, further understanding of factors predicting severe disease is needed.

Association between response to rituximab and antibody-mediated rejection in ABO-incompatible living kidney transplantation.

OBJECTIVES: To examine the association of response to rituximab and the incidence of antibody-mediated rejection in preconditioning of rituximab and plasma exchange without post-transplant plasmapheresis in patients undergoing ABO-incompatible living kidney transplantation. METHODS: A total of 115 patients who underwent ABO-incompatible living kidney transplantation at Tokyo Women's Medical University Hospital, Tokyo, Japan, were divided into two groups based on the response to rituximab: good response (n = 75) or poor response (n = 40). The rituximab good response and poor response patients were defined as patients whose CD19+ cells were non-detected (0%) and detected on the day of transplantation (2-5 days, median 3 days, after rituximab administration), respectively. RESULTS: Rituximab response and anti-A/B blood antibody titer after plasmapheresis were significant risk factors for antibody-mediated rejection (P = 0.036, 0.045, respectively). The occurrence of antibody-mediated rejection was higher in the poor response group than in the good response group (22.5% vs 8.0%; P = 0.028). The 14-day, 3-month and 1-year cumulative incidence of antibody-mediated rejection was 2.7%, 5.3% and 8.0% in the good response group, and 17.5%, 20.0% and 22.5% in the poor response group after ABO-incompatible living kidney transplantation. The patient survival was not significantly different between the two groups. However, graft survival 1 month after transplantation was lower in the poor response group. There is no significant difference in graft function and in the incidence of complications, including infection, after transplantation between the two groups. CONCLUSIONS: Antibody-mediated rejection after ABO-incompatible living kidney transplantation was significantly associated with the response to rituximab in our preconditioning protocol.

Clinical Characteristics of Jra Alloimmunization in Pregnancy: A Case Series.

Only few studies have reported on Jra alloimmunization in pregnancy, and its clinical course remains unclear. We reviewed our cases to clarify the change in the peak systolic velocity of the middle cerebral artery (MCA-PSV) during pregnancy and the critical anti-Jra antibody titer to predict fetal anemia. We collected the data of pregnant women with anti-Jra antibody from two hospitals between 2010 and 2017. We extracted data on maternal information, number of intrauterine blood transfusions (IUT), trend of anti-Jra antibody titer, changes of MCA-PSV, and neonatal outcome. We had 16 cases. IUTs were performed in 6 fetuses with severe anemia between 27 and 32 weeks' gestation. The MCA-PSV did not increase more than 1.5 multiples of the median (MoM) after 32 weeks' gestation. No significant difference was found in the maximum titer between cases with IUT and those without IUT. All pregnancies but one delivered at term. No neonates developed severe anemia or jaundice. MCA-PSV did not increase higher than 1.5 MoM later during the pregnancy. A critical titer to predict fetal anemia did not exist. Spontaneous term delivery could be expected even in fetuses who underwent IUT before 32 weeks' gestation.

Kidney transplantation across minor ABO incompatibility: the use of A2 to B transplants.

PURPOSE OF REVIEW: On 4 December 2014, the new kidney allocation system (KAS) went into effect. As part of this system, UNOS approved for the first time a national system with a specific mechanism affording priority to allocate kidneys across so-called 'minor ABO incompatibility' from blood group A2 donors into blood group B recipients. This significantly increased the number of such transplants done and the opportunities to learn about the specifics of such transplants. RECENT FINDINGS: A2 to B transplants have been demonstrated to be well tolerated, effective, and cost-effective ways of addressing disparities in the allocation system. Further data about the use of anti-A titers and the limits to successful transplant have better defined the bounds of who can benefit from such transplants. SUMMARY: The success thus far with A2 to B transplants should increase comfort and acceptance of the allocation policy changes and we should see further increases in centers willing to use such transplants to better address inequalities in the system.

Successful management of severe red blood cell alloimmunization in pregnancy with a combination of therapeutic plasma exchange, intravenous immune globulin, and intrauterine transfusion.

BACKGROUND: Antibodies to Rhesus and Kell antigens have been associated with severe hemolytic disease of the fetus and newborn (HDFN) necessitating intrauterine transfusion (IUT) of red blood cells (RBCs). We report a case series of five women with severe HDFN secondary to maternal RBC alloimmunization who were successfully managed with therapeutic plasma exchange (TPE), intravenous immune globulin (IVIG), and IUT. STUDY DESIGN AND METHODS: This is a retrospective case series of five women with severe HDFN who underwent a total of three TPE procedures during Weeks 10 to 13 of pregnancy, followed by weekly IVIG infusions. They were followed with serial middle cerebral artery peak systolic velocity studies beginning at 16 weeks' gestation to detect fetal anemia. For IUT, fetuses were administered RBC units that fully matched the maternal phenotype to D, C, E, K, Fy, Jk, and S antigen groups. The delivery outcomes and newborn information were followed. RESULTS: Anti-D and anti-K alloantibodies were implicated in HDFN. A two- to fourfold dilution reduction in anti-D and anti-K titers was observed after TPE. IUT was initiated between 21 to 27 weeks' gestation. The total number of IUTs for each patient ranged from four to seven. All five women delivered healthy infants at 33 to 38 weeks' gestation. CONCLUSION: A combined regimen of TPE and IVIG early in pregnancy and IUT later in pregnancy results in successful management of severe maternal RBC alloimmunization and HDFN. IUT with fully phenotypically matched RBC units may help prevent further RBC alloimmunization in complex cases of HDFN.

The near disappearance of fetal hydrops in relation to current state-of-the-art management of red cell alloimmunization.

OBJECTIVE: In this study, we aim to evaluate trends in the condition of fetuses and neonates with hemolytic disease at the time of first intrauterine transfusion (IUT) and at birth, in relation to routine first-trimester antibody screening, referral guidelines, and centralization of fetal therapy. METHOD: We conducted a 30-year cohort study including all women and fetuses treated with IUT for red cell alloimmunization at the Dutch national referral center for fetal therapy. RESULTS: Six hundred forty-five fetuses received 1852 transfusions between 1 January 1987 and 31 December 2016. After the introduction of routine first-trimester antibody screening, the hydrops rate declined from 39% to 15% (OR 0.284, 95% CI, 0.19-0.42, P < 0.001). In the last time cohort, only one fetus presented with severe hydrops (OR 0.482, 95% CI, 0.38-0.62, P < 0.001). Infants are born less often <32 weeks (OR 0.572, 95% CI, 0.39-0.83, P = 0.004) and with higher neonatal hemoglobin (P < 0.001). Neonatal hemoglobin was positively independently associated with gestational age at birth, fetal hemoglobin, and additional intraperitoneal transfusion at last IUT. CONCLUSION: Severe alloimmune hydrops, a formerly often lethal condition, has practically disappeared, most likely as a result of the introduction of routine early alloantibody screening, use of national guidelines, and pooling of expertise in national reference laboratories and a referral center for fetal therapy.

Effects of preoperative plasma exchange therapy with albumin replacement fluid on blood coagulation in patients undergoing ABO-incompatible living-donor kidney transplantation using rotational thromboelastometry.

BACKGROUND: ABO-incompatible living-donor kidney transplantation (LDKT) requires immunotherapy and plasma exchange therapy (PEX). PEX with albumin replacement fluid reportedly decreases fibrinogen levels. However, no reports have described the effects of PEX with albumin replacement fluid on blood coagulation parameters and blood loss during the perioperative period. Therefore, we investigated the effects of preoperative PEX on blood coagulation parameters and blood loss during the perioperative period in patients undergoing ABO-incompatible LDKT as measured by rotational thromboelastometry (ROTEM®). METHODS: Twenty-eight patients undergoing LDKT were divided into the PEX group (ABO incompatible with PEX, n = 13) and non-PEX group (ABO compatible without PEX, n = 15). ROTEM® parameters, standard laboratory test parameters, bleeding volume, and transfusion volume were compared between PEX and non-PEX group. MCEplatelet, which represents platelet contribution to clot strength and where "MCE" stands for maximum clot elasticity, was calculated from the difference in MCE between EXTEM and FIBTEM. RESULTS: The bleeding volume during surgery and the intensive care unit (ICU) stay was significantly higher in the PEX than non-PEX group (p < 0.01). Maximum clot firmness (MCF) of EXTEM (MCFEXTEM), MCFFIBTEM, and MCEplatelet was significantly lower in the PEX than non-PEX group (p < 0.01). In the PEX group, the bleeding volume during surgery was very strongly correlated with the baseline MCFEXTEM and MCEplatelet, and the bleeding volume during the ICU stay was strongly correlated with the postoperative MCFEXTEM and MCEplatelet. CONCLUSIONS: These results suggest that the increased blood loss in the PEX group during surgery and the ICU stay was associated with decreased platelet contribution to clot strength as measured by ROTEM®. TRIAL REGISTRATION: UMIN-Clinical Trial Registry UMIN000018355 . Registered 21 July 2015.

A comparison of desensitization methods: Rituximab with/without plasmapheresis in ABO-incompatible living donor liver transplantation.

BACKGROUND: Plasmapheresis is a desensitization method used prior to ABO-incompatible (ABO-I) living donor liver transplantation. However, studies on its usefulness in the rituximab era are lacking. METHODS: Fifty-six adult patients underwent ABO-I living donor liver transplantation between January 2012 and October 2015. A single dose of rituximab (300 mg/m2) was administered 2 weeks before surgery with plasmapheresis in all patients until February 2014 (RP group, n = 26). Patients were administered rituximab only, without plasmapheresis between March 2014 and October 2015 (RO group, n = 30). RESULTS: The 6-, 12- and 18-month overall survival rates were 92.3%, 80.8% and 76.9% in the RP group and 96.6%, 85.4% and 85.4% in the RO group, respectively (P = 0.574). When the initial isoagglutinin titers < 16, neither group showed a rebound rise of isoagglutinin titers. For patients with initial isoagglutinin titers ≥ 16, the rebound rise of isoagglutinin titers was more prominent in the RP group. There was no difference in time-dependent changes in B cell subpopulations and ABO-I-related complications. CONCLUSIONS: Sufficient desensitization for ABO-I living donor liver transplantation can be achieved using rituximab alone. This desensitization strategy does not affect the isoagglutinin titers, ABO-I-related complications and patient survival.

Clinical outcomes with ABO antibody titer variability in a multicenter study of ABO-incompatible kidney transplantation in the United Kingdom.

BACKGROUND: ABO blood group-incompatible kidney transplantation (ABOiKTx) outcomes are good, but complications are more common than in conventional transplantation. Regimens that use extracorporeal antibody removal therapy (EART) and enhanced immunosuppression are guided by titration of ABO blood group antibodies (using hemagglutination [HA] dilution assays), and these assays vary significantly in performance between centers. This study aims to describe the differences in titer measurement and the effect on clinical practice and outcomes. STUDY DESIGN AND METHODS: This multicentre, prospective cohort study of 100 ABOiKTx recipients assessed treatment and outcome data, including HA assay results measured retrospectively in a single central laboratory. RESULTS: Patient and allograft survival at 1 year was 99% and 94%, respectively. There were significant differences in the number of pretransplantation EART sessions in centers undertaking plasma exchange (PEx), compared with immunoadsorption (IA) (median, 6 vs. 4 sessions; p = 0.007). The pre-EART HA titer in both groups was the same when centrally assayed. The local HA assay used to guide treatment yielded significantly higher titers in centers undertaking PEx compared with IA (median, 128 vs. 32; p < 0.005). Patients undergoing PEx rather than IA were significantly more likely to suffer postoperative hematoma (12.9% vs. 1.8%; p = 0.05) or any perioperative collection requiring drainage (19.4% vs. 3.6%; p = 0.02). CONCLUSION: The colinearity of HA assay sensitivity with the receipt of PEx and EART limits some conclusions regarding the likely direction of causation. However, the association of differences in clinical practice with recognized perioperative complications of ABOiKTx identifies targets for further investigation and quality improvement.

Acute hemolytic transfusion reaction due to anti-Le(b).

BACKGROUND: Anti-Le(b) is usually a clinically insignificant antibody of immunoglobulin M subclass most often found in the sera of pregnant women or individuals that are Le(a-b-). We report a case of an acute hemolytic transfusion reaction due to a hemolytic anti-Le(b) that was not seen in the pretransfusion antibody detection test, but was strongly reactive in posttransfusion testing. CASE REPORT: A 30-year-old African-American woman with metastatic renal cell carcinoma was receiving chemotherapy. She was anemic with hemoglobin (Hb) of 7.2 g/dL and had a negative antibody detection test by the solid-phase red blood cell adherence method. She was transfused with 2 RBC units without incident. Nine days later her Hb was 7.9 g/dL again with a negative antibody detection test. Transfusion of an additional RBC unit was begun. During the transfusion she developed chills, nausea, hypertension, and red-brown urine. The posttransfusion sample plasma was grossly hemolyzed with a strongly positive direct antiglobulin test (DAT) by gel. By comparison the pretransfusion plasma was normal appearing and the DAT was weaker. The eluate was negative on both occasions. Anti-Le(b) was detected in the posttransfusion sample by MTS gel (Ortho Diagnostics). Both RBC units she had received before the RBC unit that caused the reaction were Le(b+) as was the implicated RBC unit. CONCLUSION: This case illustrates that anti-Le(b) which is usually clinically insignificant can occasionally cause severe hemolytic transfusion reactions. Only three other reported cases of anti-Le(b) causing hemolytic transfusion reactions could be found in the literature, two of which were in abstract form only.

ABO desensitization affects cellular immunity and infection control after renal transplantation.

The impact of ABO desensitization on overall immunity, infectious control, and alloreactivity remains unknown. We compared 35 ABO-incompatible kidney transplant recipients (KTRs) to a control of 62 ABO compatible KTRs. Samples were collected before, at +1, +2, +3, +6, and +12 months post-transplantation. CMV-, BKV-specific, and alloreactive T cells were measured using an interferon-γ ELISPOT assay. The extent of immunosuppression was quantified by enumeration of lymphocyte subpopulations and cytokines. No differences were observed for 5-year allograft survival and function between both groups (P > 0.05). However, ABO-incompatible KTRs were more likely to develop CMV infection, BKV-associated nephropathy, and severe sepsis (P = 0.001). Interestingly, ABO-incompatible KTRs with poor HLA-match showed the highest rates of infections and inferior allograft function (P < 0.05). CD3+, CD4+ T-cell counts, interferon-γ and IL-10 levels were lower in ABO-incompatible KTRs early post-transplantation (P < 0.05). Likewise, ABO-incompatible KTRs showed impaired BKV- and CMV-specific T-cell immunity (P < 0.05). ABO-incompatible KTRs showed lower frequencies of alloreactive T cells (P < 0.05). Our data suggest T-cell depletion due to ABO desensitization, which may contribute to the increased risk of T-cell-dependent infections. Elimination of B cells serving as antigen-presenting cells, thereby causing impaired T-cell activation, plays a significant role in both impaired infection control and reduced alloreactive T-cell activation.