Donor-specific anti-HLA antibodies (DSA) are an important cause of engraftment failure and may negatively impact survival outcomes of patients receiving allogeneic hematopoietic stem cell transplantation (HSCT) using an HLA-mismatched allograft. The incidence of DSA varies across studies, depending on individual factors, detection or identification methods and thresholds considered clinically relevant. Although DSA testing by multiplex bead arrays remains semiquantitative, it has been widely adopted as a standard test in most transplant centers. Additional testing to determine risk of allograft rejection may include assays with HLA antigens in natural conformation, such as flow cytometric crossmatch, and/or antibody binding assays, such as C1q testing. Patients with low level of DSA (20,000 MFI) may be at very high-risk for engraftment failure despite current therapies. By contrast, in patients with moderate or high level of DSA, desensitization therapy can successfully mitigate DSA levels and improve donor cell engraftment rate, with comparable outcomes to patients without DSA. Treatment is largely empirical and multimodal, involving the removal, neutralization, and blocking of antibodies, as well as inhibition of antibody production to prevent activation of the complement cascade. Desensitization protocols are based on accumulated multicenter experience, while prospective multicenter studies remain lacking. Most patients require a full intensity protocol that includes plasma exchange, while protocols relying only on rituximab and intravenous immunoglobulin may be sufficient for patients with lower DSA levels and negative C1q and/or flow cytometric crossmatch. Monitoring DSA levels before and after HSCT could guide preemptive treatment when high levels persist after stem cell infusion. This paper aims to standardize current evidence-based practice and formulate future directions to improve upon current knowledge and advance treatment for this relatively rare, but potentially serious complication in allogeneic HSCT recipients.

Since CAR-T cell therapy was initially approved in 2017, its use has become more prevalent and so have its side effects. CAR-T-related HLH, also named immune effector cell-associated HLH-like syndrome (IEC-HS), is a rare but fatal toxicity if not recognized promptly. We conducted a review of the literature in order to understand the prevalence of IEC-HS as well as clarify the evolution of the diagnostic criteria and treatment recommendations. IEC-HS occurrence varies between CAR-T cell products and the type of malignancy treated. Diagnosis can be challenging as there are no standardized diagnostic criteria, and its clinical features can overlap with cytokine release syndrome and active hematological disease. Suggested treatment strategies have been extrapolated from prior experience in HLH and include anakinra, corticosteroids and ruxolitinib. IEC-HS is a potentially fatal toxicity associated with CAR-T cell therapy. Early recognition with reliable diagnostic criteria and prompt implementation of treatment specific to IEC-HS is imperative for improving patient outcomes.

Umbilical cord blood transplantation (UCBT) has been an important donor source for allogeneic hematopoietic stem cell transplantation, especially for patients who lack suitable matched donors. UCBT provides unique practical advantages, such as lower risks of graft-versus-host-disease (GVHD), permissive HLA mismatch, and ease of procurement. However, there are clinical challenges in UCBT, including high infection rates and treatment-related mortality in selected patient groups. These clinical advantages and challenges are tightly linked with cell-type specific immune reconstitution (IR). Here, we will review IR, focusing on T and NK cells, and the impact of IR on clinical outcomes. Better understanding of the immune biology in UCBT will allow us to further advance this field with improved clinical practice.

Purpose: Patients with multiple myeloma with t(11;14) have been considered to have standard-risk disease. However, several recent reports have shown contradictory results. We identified 95 patients with multiple myeloma with t(11;14) on FISH studies, who underwent upfront autologous hematopoietic stem cell transplant (auto-HCT) at our center. We compared their outcome with a group of standard-risk patients with multiple myeloma who had diploid cytogenetics by both conventional cytogenetics (CC) and FISH (n = 287). Experimental Design: To reduce the bias between the groups, we performed a 1:1 propensity score matching technique for analysis. A total of 160 patients, 80 in each group, were identified. Patients in the 2 groups were matched for age, International staging system stage at diagnosis, serum creatinine at presentation, disease status at auto-HCT, type of preparative regimens, dose of melphalan used for conditioning, and induction and maintenance regimens. Results: Patients in t(11;14) group had a post auto-HCT overall response rate (ORR) of 97.5% (78/80), compared with 100% (80/80) in the standard-risk control group (P = 0.50). Complete response rate in the t(11;14) group was 35% (28/80), compared with 45% (36/80) in the standard-risk control group (P = 0.26). The 4-year PFS rates were 40.8% (95% CI, 29.6%–56.1%) and 51.1% (95% CI, 39.4%–66.3%) in the t(11;14) and standard-risk control groups, respectively (P = 0.14). The 4-year OS rates were 74.9% (95% CI, 63.3%–88.7%) and 88.3% (95% CI, 80.4%–97.0%) in the t(11;14) and standard-risk control groups, respectively (P = 0.17). Also, patients with t(11;14) with concurrent cytogenetics had significantly poor PFS and OS compared with a propensity matched standard-risk control group. Conclusions: Our study confirms that t(11;14) multiple myeloma undergoing upfront autologous transplantation had similar outcomes as patients with multiple myeloma with normal cytogenetic and FISH studies. Existence of additional genomic aberrations by CC or FISH was associated with a worse outcome.

At our center, we observed a series of patients who developed transudative refractory ascites secondary to noncirrhotic, non-veno-occlusive disease (VOD)–related portal hypertension after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Patients were considered to have idiopathic portal hypertension-related refractory ascites (IRA) if they developed ascites secondary to intrahepatic portal hypertension (serum ascites albumin gradient ≥1.1 g/dL or hepatic venous pressure gradient [HVPG] >5 mm Hg), but did not meet the clinical criteria for classical VOD/sinusoidal obstructive syndrome (SOS) and did not have any alternate etiology of portal hypertension. From our institutional database, we identified 40 patients who developed IRA after allo-HSCT between 2004 and 2018. The patients’ median age at the time of allo-HSCT was 54 years (range, 21-73 years). The median time to development of IRA after allo-HSCT was 80 days (range, 16-576 days). The median number of paracentesis was 3 (range, 1-11), and 15 (38%) patients had an intraperitoneal catheter placed for continued drainage of the rapidly accumulating ascites. Portal pressures were measured in 19 patients; 6 (15%) had moderate portal hypertension (HVPG 6-9 mm Hg), and 13 (33%) had severe portal hypertension (HVPG ≥ 10 mm Hg). Liver biopsy was performed in 24 patients. None of the patients met the criteria for classical VOD/SOS (clinical/histological) or cirrhosis (histological). The cumulative incidence of nonrelapse mortality was 63%, and the median survival duration after the development of the IRA was 7 months (range, 0.8-125.6 months). IRA is a poorly understood and often fatal complication of allo-HSCT.