A simple predictor for donor-specific anti-HLA antibody desensitisation in haploidentical haematopoietic stem cell transplantation.

Donor-specific HLA antibody (DSA) has been recognised as an independent risk factor for graft failure in patients undergoing haploidentical haematopoietic stem cell transplantation (HID HSCT). Therapeutic plasma exchange (TPE), as a first-line strategy for DSA desensitisation, can promptly reduce serum DSA levels. This study aimed to investigate DSA characteristics and identify a biomarker predicting the efficacy of DSA desensitisation in patients proceeding to HID HSCT. We retrospectively enrolled 32 patients with DSA from April 2021 to January 2024, and analysed the mean fluorescence intensity (MFI) value of DSA at the different time points of desensitisation treatment. Compared with baseline DSA level before TPE, the median MFI of HLA class I DSA was reduced from 8178.6 to 795.3 (p < 0.001), and HLA class II DSA decreased from 6210.9 to 808.8 (p < 0.001) after TPE. The DSA level in 1:16 diluted pre-TPE serum correlated well with DSA value in post-TPE serum (class I, r = 0.85, p < 0.0001; class II, r = 0.94, p < 0.0001), predicting TPE efficacy in 84.4% of patients. Based on the degree of DSA reduction after TPE, patients were divided into complete responders (decreased by >70%), partial responders (decreased by 30 to 70%) and non-responders (decreased by <30%) and the percentages were 43.8%, 25% and 31.2%, respectively. Non-responders receiving aggressive immunotherapy had longer overall survival compared to those receiving standard strategies (p < 0.05). The 1:16 diluted pre-TPE serum may predict the efficacy of TPE and allow for more rational immunotherapy strategy for patients with DSA proceeding to HID HSCT.

The Role of Plasmapheresis in Severe Leptospirosis Refractory to Standard Therapy: A Case Report and a Comprehensive Literature Review.

Leptospirosis, a zoonotic infection prevalent in Pakistan, presents diverse clinical manifestations ranging from mild flu-like symptoms to severe multiorgan failure known as Weil's disease. This case study reports on a 24-year-old woman with leptospirosis complicated by acute kidney injury and hyperbilirubinemia, unresponsive to standard therapies. Despite initial treatment with antibiotics and hemodialysis, her condition deteriorated. Following a single session of plasmapheresis, marked clinical and laboratory improvements were observed. Notably, plasma exchange effectively reduced bilirubin levels, underscoring its potential benefit in severe leptospirosis. This case highlights the role of plasmapheresis as rescue therapy in critically ill patients, demonstrating significant outcomes in cases resistant to conventional management. Further research is warranted to refine guidelines on the optimal timing and frequency of plasma exchange in such settings.

A rare case of acute cerebellitis due to enterovirus treated with therapeutic plasma exchange: Case report and review of the literature.

BACKGROUND: Acute cerebellitis is a rare complication of pediatric infections. There are many reports that viral infections lead to neurological manifestations, including acute cerebellitis. METHODS: A retrospective chart review was conducted for pediatric patients diagnosed with enterovirus cerebellitis between 2000 and 2024. The methods involved reviewing clinical and radiological records and assessing the treatment methods. RESULTS: Case Report We present the case of a 4-year-old immunocompetent child who initially presented with acute encephalopathy followed by truncal ataxia, and eventually received a diagnosis of postinfectious cerebellitis. Enterovirus real-time polymerase chain reaction were positive in the nasopharyngeal swab. Therapeutic plasma exchange (TPE) was started due to neurological deterioration despite IVIG treatment. She improved significantly with TPE, and methylprednisolone treatment and was discharged in good health status. The patient is being followed up as neurologically normal. CONCLUSION: Acute cerebellitis associated with enterovirus is a rare pediatric disorder. Early diagnosis and treatment with TPE in this severe case is thought to be preventive for the potentially fatal complications.

Successful treatment of severe hepatic impairment in erythropoietic protoporphyria: A case report and review of literature.

BACKGROUND: Erythropoietic protoporphyria (EPP) is a rare genetic disorder stemming from ferrochelatase gene mutations, which leads to abnormal accumulation of protoporphyrin IX primarily in erythrocytes, skin, bone marrow and liver. Although porphyria-related severe liver damage is rare, its consequences can be severe with limited treatment options. CASE SUMMARY: This case study highlights a successful intervention for a 35-year-old male with EPP-related liver impairment, employing a combination of red blood cell (RBC) exchange and therapeutic plasma exchange (TPE). The patient experienced significant symptom relief and a decrease in bilirubin levels following multiple PE sessions and an RBC exchange. CONCLUSION: The findings suggest that this combined approach holds promise for managing severe hepatic impairment in EPP.

On-treatment decline in MELD score predicts one-month transplant-free survival in rodenticidal hepatotoxicity patients treated with low-volume plasma exchange.

BACKGROUND AND AIM: Plasma exchange (PLEX) improves survival in patients with rodenticidal hepatotoxicity. However, predictors of treatment response are unknown. We aimed at assessing predictors of response to PLEX treatment in these patients. METHODS: Patients with rodenticidal hepatotoxicity from 2014 to 2023 managed in our department were included in this study. Kochi criteria (model for end-stage liver disease [MELD] score ≥ 36 or international normalized ratio [INR] ≥ 6 with hepatic encephalopathy [HE]) derived specifically for rodenticidal hepatotoxicity (PubMed IDentifier [PMID]: 26310868) were used to assess need for liver transplantation. We analyzed predictors of survival at one month. ∆Bilirubin, ∆MELD score and ∆INR were calculated as percentage change of the parameter after third PLEX session (or after last PLEX if < 3 PLEX sessions done) from baseline pre-PLEX value. RESULTS: Of 200 patients with rodenticidal hepatotoxicity, 114 patients were treated with low-volume PLEX (PLEX-LV). No patient had liver transplantation. Of 78 patients who fulfilled Kochi criteria, 32 patients were PLEX-LV eligible and underwent PLEX-LV (M: 10; age: 20.5, 7-70 years; median, range; acute liver failure: 24). Twenty-two (69%; acute liver failure: 14) of the 32 patients were alive at one month. Presence of HE (p = 0.03) and ∆MELD (p < 0.001) were significant predictors on univariate analysis, while ∆MELD (aOR = 0.88, 95% CI: 0.79-0.98, p = 0.01) was the only significant independent predictor of one-month transplant-free survival. Area under receiver operating characteristic (ROC) for ∆MELD was 0.93 (95% CI:0.85-1.00) and a decrease of ≥ 20% in MELD score while on PLEX-LV had 90% sensitivity and 90% specificity in predicting one-month survival. CONCLUSIONS: Decline in MELD while on PLEX-LV independently predicted one-month transplant-free survival in rodenticidal hepatotoxicity patients. This may help guide decision on stopping PLEX-LV in patients predicted to respond to treatment and to consider alternate treatment options in non-responders.

Immunological and therapeutic insights in autoimmune autonomic ganglionopathy: What is the position of apheresis in immunotherapy?

Autoimmune autonomic ganglionopathy (AAG) is characterized by various autonomic and extra-autonomic symptoms and is caused by autoantibodies against nicotinic acetylcholine receptors present in the autonomic ganglia (ganglionic acetylcholine receptor, gAChR), requiring immediate and aggressive intervention to prevent the exacerbation of symptoms. However, there is currently no internationally accepted standard of care for the immunotherapy of AAG, including apheresis. Although the rationale for the use of plasma exchange (PLEX) in AAG is strong, whereby pathogenic gAChR antibodies are removed, its overall impact on patient outcomes is not well-established. Based on previous case reports and small case series studies, we provide a comprehensive overview of the challenges and uncertainties surrounding the use of PLEX for the management of AAG and provide current practice recommendations to guide treatment decisions.

A case of hyperviscosity syndrome associated with Waldenström macroglobulinemia treated with membrane plasma exchange without predilution.

A 75-year-old man with blurred vision and nasal bleeding was diagnosed with hyperviscosity syndrome and central retinal vein occlusion secondary to Waldenström macroglobulinemia. Serum total protein and IgM levels were undetectable. Because of the severe symptoms, we determined that immediate plasma-exchange treatment was required to decrease the blood viscosity. The initial plasma exchange was performed using the membrane isolation method with a predilution standby. A saline predilution replacement was prepared to decrease the total membrane pressure (TMP); however, the predilution protocol was not used because the planned treatment volume could be achieved without increasing the TMP. After two consecutive days of membrane plasma exchange, all serum biochemical tests were measurable, and IgM was below 4000 mg/dL. After chemotherapy, his visual symptoms improved, and he was discharged. Since it is difficult to assess the risk of elevated TMP prior to initial plasma exchange, membrane plasma exchange with a predilution standby may be a useful strategy for initial plasma exchange for hyperviscosity syndrome in terms of safety and efficiency.

Therapeutic plasma exchange in autoimmune neurological disorders: A comprehensive evaluation of clinical outcomes, safety, and long-term disability using the modified Rankin scale.

INTRODUCTION: Autoimmune neurological diseases (ANDs) involve the immune system attacking the nervous system, leading to various symptoms. Therapeutic plasma exchange (TPE) is used to remove pathogenic autoantibodies, aiming to improve clinical outcomes. METHODS: This ambispective observational study included 99 patients with ANDs who underwent TPE from January 2018 to June 2022 at a tertiary care center in India. Clinical outcomes were measured using the modified Rankin Scale (mRS) scores at admission, post-TPE, at 3-months, 6-months, and 1-year follow-up post-discharge. Data were analyzed using Epi Info version 7.0. RESULTS: The median mRS score improved significantly from 5 (IQR 4-5) before TPE to 3 (IQR 2-4) post-TPE (p < 0.001). Complications occurred in 5.95% of procedures, with allergic reactions being the most common. The in-hospital mortality rate was 9%. CONCLUSION: TPE is a safe and effective treatment modality for autoimmune neurological diseases, especially in resource-constrained settings. It aids in both symptomatic relief and reducing long-term functional disability.

Evaluation of the results of the patients who underwent plasmapheresis in the pediatric intensive care unit.

Background/aim: Therapeutic plasma exchange (TPE) is an extracorporeal treatment method that removes large molecular weight substances from plasma. In our study, we aimed to retrospectively examine the indications and procedural methods of the patients who had undergone TPE, and the complications that occurred during the procedure. Materials and methods: Forty-one patients who were monitored in thePICU of Gazi Yasargil Training and Research Hospital and had indications for TPE between 2017 and 2021 were included in the study. Laboratory parameters were checked before and after the TPE procedure. In addition to these, patients' diagnosis, weight, type of procedure and type of device, where the procedure was performed, duration of the procedure, amount of blood and plasma processed, complications, number of procedures, and death during the procedure or independent of the procedure were evaluated. Results: The median age was 93.0 (14.0-167.0) months. Hemolytic uremic syndrome (HUS) was the most common TPE indication with nine patients. The most common complication related to TPE was fever (11 patients), while no complication was observed in 18 patients.When laboratory results were evaluated according to American Society for Apheresis (ASFA) categories, a significant improvement was observed in the values of platelet, AST, ALT, LDH, urea, and creatinine in ASFA1 after TPE. No significant improvement was observed in ASFA2 (p > 0.05). In ASFA3, a significant improvement was observed in INR, AST, ALT, LDH, total bilirubin, creatinine, pH, and lactate values after TPE (p < 0.05). Five patients died from ASFA1, one from ASFA2, and three patients from ASFA3. Conclusion: Since significant adjustments are observed in clinical and laboratory values in sepsis-MOF, which is in the ASFA3 category, we believe that it should be evaluated in the ASFA2 or ASFA1 category in the early treatment of these diseases. In addition, we think that MIS-C cases, which have not been in any category according to ASFA, should be included in the ASFA2 or ASFA3 category, considering our TPE results.

Role of plasma exchange in a post-partum case of severe thrombotic thrombocytopenic purpura with acute kidney injury.

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease present with the classic pentad of microangiopathic hemolytic anemia (MAHA), fever, neurologic changes, thrombocytopenia, and renal dysfunction. In a diagnostic dilemma, therapeutic plasma exchange (TPE) is a choice of life-saving intervention. In this, we assess the efficacy of TPE in a suspected case of post-partum TTP. A 27 years old female was admitted in an emergency on day 8 after a lower segment cesarian section (LSCS) with unresponsive behavior for 3 days and with TTP. She was normal 32 days back with her second, 7-month pregnancy. Ultrasonography (USG) showed an umbilical cord around the neck of the baby. On the fifth post-operative day, she was shifted to emergency with fever, generalized anasarca, gastrointestinal tract (GI) bleeding, low platelet count, and low Hb, with a poor Glasgow coma scale (GCS) of 6. On the bases of serum urea and serum creatinine, she presented acute kidney injury with encephalopathy. At emergency, she was unresponsive to mechanical ventilation and supportive treatment; hence, therapeutic plasma exchange was performed. After eight TPE cycles, the patient presented with an improved hematological and renal profile with good GCS. TPE is helpful and life-saving for suspected TTP patients with AKI.

Microangiopathic thrombocytopenia caused by vitamin B12 deficiency responding to plasma exchange.

A young adult African American female presented with normocytic microangiopathic haemolytic anaemia, elevated lactate dehydrogenase and thrombocytopenia. The patient responded to therapeutic plasma exchanges (TPE) for presumed thrombotic microangiopathy caused by thrombotic thrombocytopenic purpura (TTP). After relapsing, the patient was found to have pancytopenia, megaloblastic bone marrow and low vitamin B12 consistent with pernicious anaemia, which improved with intramuscular B12 and discontinuation of TPE. B12-deficient macrocytosis was not seen at presentation due to concomitant alpha-thalassaemia. Initial clinical/laboratory improvement is attributed to B12 present in TPE plasma. B12 deficiency can mimic TTP. Vigilance is needed regarding atypical presentations of pernicious anaemia.

The history of thrombotic thrombocytopenic purpura research: a narrative review.

Background and Objective: Thrombotic thrombocytopenic purpura (TTP) is a rare but debilitating thrombotic microangiopathy that results from severe deficiency of the enzyme ADAMTS13. The disorder was first described in the early 20th century, but the pathophysiology of the disease has only been elucidated in the past three decades. In this narrative review, we will summarize the milestone moments in the history of TTP research and discovery. Methods: We searched literature using PubMed from 1924 to 2023 using the following free text searches: "thrombotic thrombocytopenic purpura", "Moschcowitz disease", and "thrombotic microangiopathy". We found 6,917 peer-reviewed articles and sorted through these for relevant literature pertinent to the review. A total of 46 articles were included for review and the remainder were excluded. Key Content and Findings: The history of TTP research was reviewed, with a sampling of major events in the evolution of the understanding of the pathophysiology and treatment of the disease discussed here. There remains much to be learned about the nature of the disease in order to develop more specific and less harmful treatments. Conclusions: An overview of the major discoveries that have led to our current understanding of TTP reveals the results of collaboration of multiple groups of physicians and scientists through the past century, with additional breakthroughs likely to occur in the future because of that same collaborative spirit.

Efficacy and Safety of Rescue Treatment with Plasma Exchange in Patients with Acute Inflammatory Neurological Disorders: A Single Center Experience.

BACKGROUND: Therapeutic plasma exchange (TPE) is a highly effective rescue treatment for patients with acute exacerbation of neuroimmunological disease that removes circulating autoantibodies and inflammatory components from the bloodstream. The aims of this study are to explore the safety and the effectiveness of TPE in patients with autoimmune neurological disorders. METHODS: We retrospectively evaluated the frequency of adverse events (AEs) and the effectiveness of TPE using the modified Ranking Scale (mRS) in patients with acute neurological flares who underwent TPE at the University Hospital of Palermo. RESULTS: Of 59 patients, the majority underwent TPE due to multiple sclerosis (MS) relapse. In 23.7% of cases, TPE was performed before obtaining a definite diagnosis due to the severity of the clinical presentation. After TPE, the mRS score was globally reduced (p < 0.0001), and this effect was marked in patients with MS, Guillain-Barré syndrome, and myasthenia gravis crisis but not in those with paraneoplastic syndromes. Circulating pathogenetic antibodies, younger age, and the early use of TPE were factors strongly associated with TPE effectiveness. The overall safety profile of TPE was satisfactory with an AE frequency of 15%. CONCLUSIONS: These results highlight the early use of TPE in patients with circulating pathogenetic antibodies as well as its favorable safety profile.

Bloodstream infections among patients receiving therapeutic plasma exchanges in the intensive care unit: a 10 year multicentric study.

BACKGROUND: Therapeutic plasma exchanges (TPE), which affect the humoral response, are often performed in combination with immunosuppressive drugs. For this reason, TPE may be associated with an increased susceptibility to infections. We aimed to describe blood stream infection (BSI) incidence in ICU patients treated with TPE and to identify associated risk factors. METHODS: We retrospectively included patients that had received at least one session of TPE in the ICU of one of the 4 participating centers (all in Paris, France) between January 1st 2010 and December 31th 2019. Patients presenting with a BSI during ICU stay were compared to patients without such an infection. Risk factors for BSI were identified by a multivariate logistic regression model. RESULTS: Over 10 years in the 4 ICUs, 387 patients were included, with a median of 5 [2-7] TPE sessions per patient. Most frequent indications for TPE were thrombotic microangiopathy (47%), central nervous system inflammatory disorders (11%), hyperviscosity syndrome (11%) and ANCA associated vasculitis (8.5%). Thirty-one patients (8%) presented with a BSI during their ICU stay, a median of 7 [3-11] days after start of TPE. In a multivariate logistic regression model, diabetes (OR 3.32 [1.21-8.32]) and total number of TPE sessions (OR 1.14 [1.08-1.20]) were independent risk factors for BSI. There was no difference between TPE catheter infection related BSI (n = 11 (35%)) and other sources of BSI (n = 20 (65%)) regarding catheter insertion site (p = 0.458) or rate of TPE catheter related deep vein thrombosis (p = 0.601). ICU course was severe in patients presenting with BSI when compared to patients without BSI, with higher need for mechanical ventilation (45% vs 18%, p = 0.001), renal replacement therapy (42% vs 20%, p = 0.011), vasopressors (32% vs 12%, p = 0.004) and a higher mortality (19% vs 5%, p = 0.010). CONCLUSION: Blood stream infections are frequent in patients receiving TPE in the ICU, and are associated with a severe ICU course. Vigilant monitoring is crucial particularly for patients receiving a high number of TPE sessions.

Beneficial therapeutic plasma exchange response in the treatment of severe relapses in patients with multiple sclerosis.

PURPOSE: Therapeutic plasma exchange (PLEX) is effective as a second-line treatment of severe relapses of multiple sclerosis (MS) that failed to respond to standard steroid therapy. Our objective was to evaluate the effectiveness of PLEX in the severe MS relapses in a cohort of patients treated at Neurology Clinic, University Clinical Centre of Serbia, Belgrade, from 2007 until 2020. METHODS: This retrospective study comprised 107 MS patients with 127 severe relapses treated with PLEX. Majority of our patients suffered from relapsing remitting MS (83.2%), 12.1% had secondary progressive MS and 4.7% had primary progressive MS. Mean age was 39.2 years (range, 19-79 years), female/male ratio 2.3:1. Pulse corticosteroid treatment was used before PLEX in 99.3% of patients. Median EDSS score at nadire during relapse was 6.0 (range 2.0-10.0). After PLEX, 73.8% relapses showed a marked clinical improvement, 7.1% showed mild improvement and in 19.0% there was no improvement. Median EDSS at discharge was 4.0 (6.0 at nadir of relapse vs. 4.0 at discharge; p<0.0001) and it was sustained at the same level, 6 month after PLEX. Multivariate regression analysis showed that higher EDSS at nadir during relapse (OR=0.63, 95% CI 0.41-0.96, p=0.039) and older age (OR=1.07, 95% CI 1.02- 1.12, p=0.010) were significantly associated with poor treatment response after 6- month follow-up. Adverse events occurred in 17.3 of procedures and they were completely resolved. CONCLUSION: Our study in a large cohort of MS patients confirmed that PLEX is effective.

Treatment of severe hypertriglyceridemia through therapeutic plasma exchange in patients with acute pancreatitis or at risk of developing it. / Tratamiento de la hipertrigliceridemia grave mediante recambio plasmático terapéutico en pacientes con pancreatitis aguda o en riesgo de padecerla.

INTRODUCTION AND OBJECTIVES: TPE drastically reduces serum triglyceride (sTG), but its role in the treatment of hypertriglyceridemia-induced acute pancreatitis (HTG-AP) or at risk of developing it, is not well established. The objectives were to assess the effectiveness and safety of TPE in the treatment of severe HTG (sHTG), as well as to evaluate the severity of HTG-AP treated with TPE. MATERIALS AND METHODS: Observational-retrospective-single-center study, in which a descriptive analysis of sHTG treated with TPE was conducted, with the aim of treating HTG-AP or preventing its recurrence. TPE was performed if sTG≥ 1000 mg/dL after 24 hours of admission. RESULTS: 42 TPE were performed to treat 35 sHTG in 23 patients: 29 HTG-AP, and 6 sHTG with previous HTG-AP. Among the patients, 37% (13/55) were women, with 37 ± 14 years-old, 74.3% had normal BMI (25/35), 34% (12/35) were drinking > 40 g/alcohol/day and 54% (19/35) were diabetics. TPE significantly reduced the baseline sTG (4425 ± 2782 mg/dL vs. 709 ± 353 mg/dL, p < 0.001) in a single session, achieving a mean percentage reduction of 79 ± 13%; 20% (7/35) of sHTG cases required two TPE sessions to reduce sTG to < 1000 mg/dL. Adverse effects were reported in 4/42 TPE sessions (9,5%). sHTG-AP was observed in 3% of cases (1/29), and there were no deaths. sTG at 24 hours of admission showed no relation with the severity of APs. CONCLUSION: The treatment of sHTG with TPE, with the aim of treating HTG-AP or preventing its recurrence, reduces sTG quickly and safety.

A multi-institutional survey of apheresis services among institutions in the United States.

INTRODUCTION: Apheresis practices in the United States (US) have not been comprehensively characterized to date. This study aimed to address this gap by evaluating apheresis therapy through a national survey. METHODS: A multi-institutional survey was conducted between April and July 2023. The survey, comprising 54 questions, focused on institutional demographics, procedures, equipment, staffing, training, and impacts of the Coronavirus Disease 2019 (COVID-19) pandemic. Responses from 22 institutions, primarily academic medical centers, were analyzed. RESULTS: Therapeutic plasma exchange (TPE) was the most common procedure, followed by hematopoietic progenitor cell collection (HPC-A) and red blood cell exchange (RCE). CAR-T cell collections were widespread, with some institutions supporting over 30 protocols concurrently. Most sites used the Spectra Optia Apheresis System, were managed by a transfusion medicine service, and employed internal apheresis providers. Insufficient staffing levels, exacerbated by the COVID-19 pandemic, were common and most often addressed using overtime. DISCUSSION: The survey highlighted the ubiquity of TPE, expanding cellular collections and staffing challenges. The role of apheresis in supporting cellular therapy, particularly in newly developing cell and gene therapies and clinical trials, was evident. Staffing issues during the pandemic emphasized the need for innovative recruitment strategies. CONCLUSION: This nationwide survey provides the most comprehensive analysis to date of apheresis practices in large US academic centers.

Pure red cell aplasia among ABO mismatched hematopoietic stem cell transplant recipients: a 13-years retrospective study and literature review.

Background: Pure red cell aplasia (PRCA) is a possible complication after allogeneic hematopoietic stem cell transplantation (HSCT) with major ABO incompatibility. Patients experience delayed engraftment of the erythroid series, with prolonged transfusion-dependent anemia and iron overload. Methods: We performed a revision of the most recent literature about post-HSCT PRCA treatment procedures. Moreover, we conducted a retrospective study, over the last 13-years, which included all consecutive major ABO mismatched HSCT performed in our unit, with the aim to assess PRCA incidence, risk factors, and response to different treatments. Overall, 194 patients received a major ABO mismatched transplant from 2010 to 2022. For each patient, data about demographic and transplant characteristics, engraftment, blood transfusion, and possible treatment received were collected. Results: The literature review returned 23 eligible papers on PRCA treatment, with high success rate using plasma-exchange (PEX) and immunoadsorption procedures, daratumumab, and eltrombopag. Our study identified a total of 24 cases of PRCA. Among risk factors for PRCA development, we have found older recipient age (p=0.01), high pre-HSCT IgG and IgM IHA titer (p<0.0001), major rather than bidirectional ABO incompatibility (p=0.02), low T CD8 lymphocyte count in the graft (p=0.006), relative donor (p=0.02) and bone marrow as stem cell source (p=0.002). However, multivariate analysis confirmed only pre-HSCT IgG IHA titer as the unique risk factor for PRCA occurrence. The optimal cut-off value of pre-HSCT IgG IHA for PRCA development, resulted to be 1/64, with a 100% sensitivity and 68.8% specificity (p<0.0001). All patients with PRCA had received rhEPO and transfusion support and 20 patients received additional treatments like PEX, rituximab, and more recently daratumumab. Comprehensively, PEX and rituximab obtained a response in half of the cases, at a variable time, while the few cases of patients we treated with daratumumab suggest promising results. The overall response rate in our cohort was 75%, with significantly better survival (94.4% vs. 16.7%) and lower transplant-related mortality (6.3% vs. 80%) for PRCA responders. Conclusions: Standardized guidelines on when and how to treat PRCA are necessary because the current treatment is controversial among centers.

A Randomized Trial Comparing Imlifidase to Plasmapheresis in Kidney Transplant Recipients With Antibody-Mediated Rejection.

BACKGROUND: Antibody-mediated rejection (ABMR) poses a barrier to long-term graft survival and is one of the most challenging events after kidney transplantation. Removing donor specific antibodies (DSA) through therapeutic plasma exchange (PLEX) is a cornerstone of antibody depletion but has inconsistent effects. Imlifidase is a treatment currently utilized for desensitization with near-complete inactivation of DSA both in the intra- and extravascular space. METHODS: This was a 6-month, randomized, open-label, multicenter, multinational trial conducted at 14 transplant centers. Thirty patients were randomized to either imlifidase or PLEX treatment. The primary endpoint was reduction in DSA level during the 5 days following the start of treatment. RESULTS: Despite considerable heterogeneity in the trial population, DSA reduction as defined by the primary endpoint was 97% for imlifidase compared to 42% for PLEX. Additionally, imlifidase reduced DSA to noncomplement fixing levels, whereas PLEX failed to do so. After antibody rebound in the imlifidase arm (circa days 6-12), both arms had similar reductions in DSA. Five allograft losses occurred during the 6 months following the start of ABMR treatment-four within the imlifidase arm (18 patients treated) and one in the PLEX arm (10 patients treated). In terms of clinical efficacy, the Kaplan-Meier estimated graft survival was 78% for imlifidase and 89% for PLEX, with a slightly higher eGFR in the PLEX arm at the end of the trial. The observed adverse events in the trial were as expected, and there were no apparent differences between the arms. CONCLUSION: Imlifidase was safe and well-tolerated in the ABMR population. Despite meeting the primary endpoint of maximum DSA reduction compared to PLEX, the trial was unsuccessful in demonstrating a clinical benefit of imlifidase in this heterogenous ABMR population. TRIAL REGISTRATION: EudraCT number: 2018-000022-66, 2020-004777-49; ClinicalTrials.gov identifier: NCT03897205, NCT04711850.