Listeria monocytogenes infections in hematopoietic cell transplant recipients: clinical manifestations and risk factors: A multinational retrospective case control study of the Infectious Diseases Working Party (IDWP) of the European Society for Blood and Marrow Transplantation (EBMT).

BACKGROUND: Listeriosis is rare after hematopoietic stem cell transplantation (HCT). Little is known about listeriosis in this population. OBJECTIVES: To describe listeriosis following HCT and assess risk factors for listeriosis. STUDY DESIGN: In this retrospective international case control study, we described 41 listeriosis episodes during 2000-2021 in HCT recipients (111 transplant centers; 30 countries) and assessed risk factors for listeriosis by comparing to matched controls. RESULTS: Forty-one listeriosis episodes (all due to Listeria monocytogenes, LM) in 30 allo- and 11 auto-HCT recipients occurred at a median of 6.2 (interquartile range [1Q-3Q] 1.6-19.3) months post-HCT. The estimated incidence was 49.8/100,000 in allo-HCT, and 13.7/100,000 population in auto-HCT. The most common manifestations were fever (39; 95%), headache (9; 22%), diarrhea, and impaired consciousness (8 each; 20%); 4 (10%) presented with septic shock; 19/38 (50%) were severely lymphocytopenic. Thirty-seven (90%) patients had LM bacteremia. Eleven (27%) patients had neurolisteriosis; 4/11 presented with non-specific signs, and 5/11 had normal brain imaging. Cerebrospinal fluid (CSF) analysis revealed high protein and, mainly neutrophilic, pleocytosis. Three-months mortality was 7/41 (17%): 3/11 (27%) among neurolisteriosis, and 4/30 (13%) among non-neurolisteriosis cases. In the multivariate analysis comparing to 74 controls, ≥2 HCT (OR [95%CI] 5.84 [1.10-30.82], p=0.038); and lymphocytopenia<500 cells/mm3 (OR [95%CI] 7.54 [1.50-37.83], p=0.014) were significantly associated with listeriosis. There were no statistically significant differences in background characteristics, immunosuppression, and cotrimoxazole prophylaxis between cases and controls. CONCLUSIONS: HCT patients have an increased risk for listeriosis compared to general population. Listeriosis cause severe disease with septic shock and mortality. Neurolisteriosis can present with non-specific signs and normal imaging. Lymphocytopenia and non-first HCT are associated with increased risk of listeriosis; cotrimoxazole was not protective.

Utility of echocardiogram in neutropenic patients with gram positive bacteremia - a retrospective study.

INTRODUCTION: Hemato-oncology patients are vulnerable to bloodstream infections due to immunocompromised state and use of intravascular catheters. Data regarding risk of infective endocarditis (IE) among those with gram positive bacteremia is limited. We aimed to evaluate the incidence of IE among neutropenic hemato-oncology patients, and to explore the yield of echocardiogram in this population. METHODS: we conducted a single retrospective study of all hospitalized hemato-oncology neutropenic patients with gram positive blood cultures between 2007 and 2021. Data regarding Patients' characteristics, blood cultures and echocardiogram was collected. RESULTS: Study included 241 patients, with 283 isolates. Coagulase negative staphylococcus (CONS) were the most commonly isolates found, followed by streptococcus viridans. Trans thoracic echocardiography (TTE) was performed in 45% of patients overall, of which 5.8% had additional Trans esophageal echocardiogram (TEE). Only a single case of IE was identified; 47 y/o multiple myeloma patient with neutropenic fever, streptococcus viridans bacteremia, and stroke caused by septic emboli. TTE and TEE failed to demonstrate valvular pathology consistent with IE. Conclusion In our experience, the yield of echocardiogram in hemato-oncological neutropenic patients with bacteremia is extremely low, owing to reduced probability of IE in this population, and thus could be avoided in most cases.

Pneumocystis Pneumonia After Allogeneic Hematopoietic Cell Transplantation: A Case-Control Study on Epidemiology and Risk Factors on Behalf of the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation.

Pneumocystis pneumonia (PCP) is a life-threatening complication after allogeneic hematopoietic cell transplantation (allo-HCT). However, allo-HCT procedures have evolved toward older patients, unrelated donors, and reduced-intensity conditioning, possibly modifying the risks. Polymerase chain reaction (PCR), widely used nowadays, is more sensitive than microscopy diagnostic methods. This study aimed to assess the factors associated with PCP in allo-HCT recipients within 2 years of HCT and managed according to current procedures. This multicenter, nested case-control study included PCP cases diagnosed by PCR, cytology, or immunofluorescence on bronchoalveolar lavage fluid between 2016 and 2018. Two controls per case were selected from the ProMISe registry and matched for the center, transplant date, and underlying disease. Fifty-two cases and 104 controls were included among the 5452 patients who underwent allo-HCT in the participating centers. PCP occurred at a median of 11.5 months after transplantation. The mortality rate was 24% on day 30 after the PCP diagnosis and 37% on day 90. The clinical presentation and mortality rates of the 24 patients diagnosed using only PCR were not different from those diagnosed with microscopy methods. Our study demonstrates a substantial incidence of, and mortality from, PCP, after allogeneic HCT despite well-established prophylactic approaches. In our experience, PCP nowadays occurs later after transplant than previously reported, justifying the prolongation of prophylaxis after six months in many cases. Allo-HCT recipients diagnosed with PCR as the only PCP marker should benefit from specific treatment as for other patients.

Upper and/or Lower Respiratory Tract Infection Caused by Human Metapneumovirus After Allogeneic Hematopoietic Stem Cell Transplantation.

BACKGROUND: Human metapneumovirus (hMPV) epidemiology, clinical characteristics and risk factors for poor outcome after allogeneic stem cell transplantation (allo-HCT) remain a poorly investigated area. METHODS: This retrospective multicenter cohort study examined the epidemiology, clinical characteristics, and risk factors for poor outcomes associated with human metapneumovirus (hMPV) infections in recipients of allo-HCT. RESULTS: We included 428 allo-HCT recipients who developed 438 hMPV infection episodes between January 2012 and January 2019. Most recipients were adults (93%). hMPV infections were diagnosed at a median of 373 days after allo-HCT. The infections were categorized as upper respiratory tract disease (URTD) or lower respiratory tract disease (LRTD), with 60% and 40% of cases, respectively. Patients with hMPV LRTD experienced the infection earlier in the transplant course and had higher rates of lymphopenia, neutropenia, corticosteroid use, and ribavirin therapy. Multivariate analysis identified lymphopenia and corticosteroid use (>30 mg/d) as independent risk factors for LRTD occurrence. The overall mortality at day 30 after hMPV detection was 2% for URTD, 12% for possible LRTD, and 21% for proven LRTD. Lymphopenia was the only independent risk factor associated with day 30 mortality in LRTD cases. CONCLUSIONS: These findings highlight the significance of lymphopenia and corticosteroid use in the development and severity of hMPV infections after allo-HCT, with lymphopenia being a predictor of higher mortality in LRTD cases.

Extracorporeal photopheresis induces NETosis in neutrophils derived from patients with chronic graft-vs-host disease.

INTRODUCTION: Extracorporeal photopheresis (ECP) is considered an effective treatment for patients with chronic graft vs host disease (cGVHD) and demonstrates efficacy in ameliorating GVHD. The mechanism by which ECP acts against cGVHD is not fully understood. Preliminary observations have hinted at the potential involvement of neutrophil extracellular traps (NETs) formation in the pathogenesis of cGVHD. We aimed to assess the influence of ECP on the formation of NETs in patients with cGVHD as a potential mechanism in this setting. METHODS: Patients treated with ECP for cGVHD at the Rabin Medical Center were included in this study. Blood samples were obtained at three different time points: before starting an ECP cycle, at the end of the first day of treatment, and 24 h following the initiation of the ECP treatment cycle. Neutrophils were harvested from all blood samples. NET formation was assessed by measurement of NET-bound specific neutrophil elastase activity and by immunofluorescence staining. RESULTS: Six patients (two females and four males) with cGVHD were included in the study. We observed a significant increase in NET formation among all six patients following ECP. Net-bound specific neutrophil elastase activity was elevated from a median value of 2.23 mU/mL (interquartile range [IQR] 2.06-2.47 mU/mL) at baseline to a median value of 13.06 mU/mL (IQR 10.27-15.97 mU/mL) immediately after the treatment and to a peak median value of 14.73 mU/mL (IQR 9.6-22.38 mU/mL) 24 h following the initiation of the ECP cycle. A qualitative assessment of NET formation using immunofluorescence staining has demonstrated markedly increased expression of citrullinated histone H3, a marker of NET formation, following ECP treatment. CONCLUSIONS: Our preliminary data indicate that ECP induces NET formation among patients with cGVHD. The contribution of increased NET formation to the therapeutic effect of cGVHD should be further investigated.

Survival advantage of treosulfan plus fludarabine (FT14) compared to busulfan plus fludarabine (FB4) in active acute myeloid leukemia post allogeneic transplantation: an analysis from the European Society for Blood and Marrow Transplantation (EBMT) Acute Leukemia Working Party (ALWP).

We compared FT14 (fludarabine 150-160 mg/m2, treosulfan 42 g/m2) versus FB4 (fludarabine 150-160 mg/m2, busulfan 12.8 mg/kg) in acute myeloid leukemia (AML) transplanted at primary refractory/relapsed disease. We retrospectively studied: (a) adults diagnosed with AML, (b) recipients of first allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated/sibling donor (2010-2020), (c) HSCT with primary refractory/relapsed disease, (d) conditioning regimen with FT14 or FB4. We studied 346 patients, 113 transplanted with FT14, and 233 with FΒ4. FT14 patients were significantly older, more frequently had an unrelated donor and had received a lower dose of fludarabine. Cumulative incidence (CI) of acute graft-versus-host disease (GVHD) grade III-IV and extensive chronic GVHD was similar. With a median follow-up of 28.7 months, 2-year CI of relapse was 43.4% in FT14 versus 53.2% in FB4, while non-relapse mortality (NRM) was respectively 20.8% versus 22.6%. This led to 2-year leukemia-free survival (LFS) of 35.8% for FT14 versus 24.2% in FB4, and overall survival (OS) of 44.4% versus 34%. Adverse cytogenetics and conditioning regimen independently predicted CI of relapse. Furthermore, conditioning regimen was the only independent predictor of LFS, OS, and GVHD-free/relapse-free survival. Therefore, our real-world multicenter study suggests that FT14 is associated with better outcomes in primary refractory/relapsed AML.

Lung Transplantation for Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation: A Single-center Experience.

BACKGROUND: Late-onset pulmonary complications can occur following hematological stem cell transplantation (HSCT). In allogeneic HSCT these complications are often associated with chronic graft-versus-host disease (GVHD). Lung transplantation (LTx) often remains the only viable therapeutic option in these patients. OBJECTIVES: To describe our experience with LTx due to GVHD after HSCT and to compare the long-term survival of this group of patients to the overall survival of our cohort of LTx recipients for other indications. METHODS: We retrospectively retrieved all data on patients who had undergone LTx for end-stage lung disease as a sequela of allogeneic HSCT, between 1997 and 2021, at Rabin Medical Center in Israel. RESULTS: A total of 15 of 850 patients (1.7%) from our cohort of LTx recipients fulfilled the criteria of LTx as a sequela of late pulmonary complication after allogeneic HSCT. The median age at the time of HSCT was 33 years (median 15-53, range 3-60). The median time between HSCT and first signs of chronic pulmonary GVHD was 24 months (interquartile range [IQR] 12-80). The median time from HSCT to LTx was 96 months (IQR 63-120). Multivariate analysis showed that patients transplanted due to GVHD had similar survival compared to patients who were transplanted for other indications. CONCLUSIONS: LTx for GVHD after allogeneic HSCT constitutes an important treatment strategy. The overall survival appears to be comparable to patients after LTx for other indications.

Infection prevention practices among EBMT hematopoietic cell transplant centers: the EBMT Infectious Disease Working Party survey.

We aimed to describe the current status of infection prevention practices among EBMT centers. Questionnaires were distributed to all 553 EBMT transplant centers to capture clinical practices regarding antimicrobial prophylaxis, protective measures, isolation procedures and growth-factor support of patients undergoing hematopoietic cell transplantation. Responses from 127 centers in 32 countries were obtained. Most centers housed patients in single rooms (autologous-82%; allogeneic-98%), with high-efficiency particulate air (HEPA)-filters (autologous-73%; allogeneic-100%) and positive pressure (autologous-61%; allogeneic-88%). Pre-engraftment G-CSF was utilized by 77 and 31% of centers after autologous and allogeneic transplantation, respectively (P < 0.00001). Antibacterial prophylaxis was provided by 57 and 69% (P = 0.086) of centers and antifungal prophylaxis by 65 and 84% (P = 0.0008) of centers, to patients undergoing autologous and allogeneic transplantation, respectively. Yet, 16 and 3% of centers provided neither antibacterial nor antifungal prophylaxis to patients undergoing autologous and allogeneic transplantation, respectively. Considerable variation existed between centers and across countries in antimicrobial prophylaxis practices, medications employed and duration of preventive therapy. There were considerable discordances between guidelines and daily practices. JACIE accredited and non-accredited centers did not differ significantly in their antimicrobial prophylaxis practices. Whether these differences between transplant centers translated into differences in infectious morbidity, mortality and financial costs, warrants further research.

The role of additional chemotherapy prior to autologous HCT in patients with relapse/refractory DLBCL in partial remission-A retrospective multicenter study.

OBJECTIVES: To evaluate the role of additional chemotherapy before autologous hematopoietic cell transplantation (HCT) in patients with relapse/refractory diffuse large B-cell lymphoma (DLBCL) who achieve partial remission following first salvage therapy. METHODS: We conducted a multicenter retrospective study of all adult patients with DLBCL who underwent HCT between 2008 and 2020 and achieved partial response (PR) after the first salvage and were either referred directly to HCT (n = 47) or received additional salvage therapy before HCT (n = 22). RESULTS: Post-HCT CR rate and progression-free survival were comparable between the two groups (66% vs. 68%, p = .86 and median not reached vs. 10.2 months [95% confidence interval, CI 7.1-12.3], p = .27, respectively). Median overall survival (OS) and estimated 3-year OS favored patients who were directly referred to HCT (105.8 [95% CI 63-148] months vs. 14.5 [95% CI 0-44] months, p = .035, and 65% [95% CI 51%-75%] vs. 40% [95% CI 21%-53%], p = .035, respectively). In Cox regression model, while International Prognostic Index and primary refractory versus relapse disease did not impact OS, allocation to a second salvage regimen and older age were both associated with inferior survival (hazard ratio [HR] = 2.57 95% CI 1.1-5.8, p = .023 and HR = 1.04 95% CI 0.99-1.2, p = .064, respectively). CONCLUSIONS: Referring patients with chemotherapy-sensitive disease in PR directly to HCT is associated with better OS compared to those receiving additional lines of treatment.

Allogeneic Hematopoietic Cell Transplantation after Chimeric Antigen Receptor T Cell Therapy in Large B Cell Lymphoma.

Anti-CD19 chimeric antigen receptor T cell (CAR-T) therapy has transformed the care of patients with relapsed/refractory large B cell lymphoma (LBCL). However, approximately 60% of CAR-T recipients ultimately will experience disease recurrence or progression. Salvage therapies after CAR-T treatment failures are of limited efficacy and have a short duration of response. The objective of the present study was to evaluate the role of allogeneic hematopoietic cell transplantation (allo-HCT) after CAR-T therapy in LBCL patients. This was a multicenter observational study reporting the outcome of 39 adult LBCL patients who underwent allo-HCT following anti-CD19 CAR-T therapy. The median patient age was 47 years (range, 20 to 68 years). HLA-matched sibling, HLA-matched unrelated, and alternative donors were used in 36%, 36%, and 28% of transplantations, respectively. Conditioning regimens were primarily of low or intermediate intensity. Disease status at allo-HCT was complete response in 41%, partial response in 38%, and progressive disease in 21%. Allo-HCT was performed at a median of 127 days (range, 82 to 206 days) after CAR-T therapy. A high incidence of hepatic toxicity (28%), including sinusoidal obstruction syndrome (15.4%; 95% confidence interval; [CI], 6.2% to 28.5%), was observed. The 1-year cumulative incidence of grade II-IV and grade III-IV acute graft-versus-host disease (GVHD) was 38.5% (95% CI, 23.2% to 53.6%) and 15.4% (95% CI, 6.1% to 28.5%), respectively. The 2-year cumulative incidence of moderate-severe chronic GVHD was 11.1% (95% CI, 3.3% to 24.3%). Overall, 2-year nonrelapse mortality and relapse/progression incidence were 26% (95% CI, 13% to 41%) and 43% (95% CI, 27% to 59%), respectively. With a median follow-up of 32 months, the 2-year overall survival (OS) and progression-free survival (PFS) were 45% (95% CI, 31% to 66%) and 31% (95% CI, 19% to 50%), respectively. In multivariable analyses, pre-HCT elevated lactate dehydrogenase level and transformed lymphoma were predictive of OS and PFS, respectively. Our data suggest that allo-HCT after anti-CD19 CAR-T treatment failure is feasible with a relatively promising efficacy but possibly high toxicity rate.

Anti-immunoglobulin-like transcript 3 induced acute myocarditis-A case report.

To the best of our knowledge, this is the first published report of anti-immunoglobulin-like transcript 3 (ILT3)-induced myocarditis. A 48-year old female patient with refractory acute myeloid leukemia who was given a single dose of anti-ILT3 monotherapy presented with fever, hypotension, chest pain, and elevated cardiac biomarkers. Systolic bi-ventricular function was in normal limits. The patient was promptly treated with pulse dose steroids with a rapid hemodynamic and clinical improvement and declining levels of cardiac biomarkers. The diagnosis of acute myocarditis was confirmed using cardiac magnetic resonance imaging applying the revised Lake Lewis criteria. While larger-scale data are needed in order to assess the incidence, management and prognosis of anti-ILT-3 induced myocarditis, we believe a high level of suspicion for adverse non-target cardiac effects is required in patients receiving this novel class of drugs.

Chimeric antigen receptor T-cell therapy is superior to standard of care as second-line therapy for large B-cell lymphoma: A systematic review and meta-analysis.

Treatment with high-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is considered standard of care (SOC) second-line treatment for relapsed or refractory large B-cell lymphoma (LBCL). However, outcomes remain suboptimal. A systematic review and meta-analysis of randomised controlled trials comparing efficacy and safety of SOC versus chimeric antigen receptor T-cell (CAR-T) therapy as second-line for patients with LBCL refractory or relapsing within 12 months. Outcomes included overall survival (OS), event-free survival (EFS), overall response rate (ORR) and safety. Three trials published in 2021 (involving 865 participants) fulfilled the eligibility criteria. EFS as well as OS were significantly improved with CAR-T therapy as compared to SOC, hazard ratio (HR) 0.57 (95% confidence interval [CI] 0.49-0.68) and HR 0.77 (95% CI 0.60-0.98) respectively. CAR-T therapy was associated with significantly better ORR, relative risk (RR) 1.55 (95% CI 1.12-2.13, p = 0.001). The risk of Grade III/IV adverse event was comparable between the two arms, RR 1.03 (95% CI 0.93-1.14). In summary, CAR-T therapy has superior outcomes as compared to SOC in patients with LBCL refractory or relapsing within 12 months, without excess of toxicity. Longer follow-up is needed to confirm these results and determine the optimal sequencing of CAR-T therapy in the management of LBCL.

Gilteritinib monotherapy for relapsed/refractory FLT3 mutated acute myeloid leukemia: a real-world, multi-center, matched analysis.

Patients with FLT3-mutated relapsed or refractory (R/R) acute myeloid leukemia (AML) have a dismal prognosis. Gilteritinib is a FLT3 tyrosine kinase inhibitor (TKI) recently approved for patients with R/R AML. We aimed to characterize real-world data regarding gilteritinib treatment in FLT3-mutated R/R AML and to compare outcomes with matched FLT3-mutated R/R AML patients treated with chemotherapy-based salvage regimens. Twenty-five patients from six academic centers were treated with gilteritinib for FLT3-mutated R/R AML. Eighty percent were treated with a prior intensive induction regimen and 40% of them received prior TKI therapy. Twelve patients (48%) achieved complete response (CR) with gilteritinib. The estimated median overall survival (OS) of the entire cohort was eight (CI 95% 0-16.2) months and was significantly higher in patients who achieved CR compared to those who did not (16.3 months, CI 95% 0-36.2 vs. 2.6 months, CI 95% 1.47-3.7; p value = 0.046). In a multivariate cox regression analysis, achievement of CR was the only predictor for longer OS (HR 0.33 95% CI 0.11-0.97, p = 0.044). Prior TKI exposure did not affect OS but was associated with better event-free survival (HR 0.15 95% CI 0.03-0.71, p = 0.016). An age and ELN-risk matched comparison between patients treated with gilteritinib and intensive salvage revealed similar response rates (50% in both groups); median OS was 9.6 months (CI 95% 2.3-16.8) vs. 7 months (CI 95% 5.1-8.9) in gilteritinib and matched controls, respectively (p = 0.869). In conclusion, in the real-world setting, gilteritinib is effective, including in heavily pre-treated, TKI exposed patients.

Venetoclax in combination with FLAG-IDA-based protocol for patients with acute myeloid leukemia: a real-world analysis.

Venetoclax in combination with intensive therapies is explored in both the upfront and relapse/refractory (R/R) setting, and available data suggest that such regimens are effective albeit with added hematological and infectious toxicity. We conducted a multicenter retrospective cohort study of patients with acute myeloid leukemia (AML) treated with venetoclax in combination with FLAG-IDA protocol. Twenty-five patients were included in this analysis (median age 53.4 years). Most patients were treated for R/R AML (n = 24, 96%) with a median of one (range 0-3) previous lines of therapy and 44% of patients (n = 11) having prior allogeneic hematopoietic cell transplantation (HCT). Median follow-up was 10 (range, 4-26) months. Platelet and neutrophil recovery were observed at a median of 31 (95% CI 17.6-38.3) and 23 (95% CI 20-28) days, respectively. The most common adverse events were infectious (blood stream infections, 48% and invasive fungal infections, 32%). Thirty-day mortality was 12%. Composite complete remission (CRc) was 72% for the entire cohort and 91% in patients treated for post-HCT relapse. Incidences of relapse-free and overall survival at 12 months were 67% (95% CI 58-76%) and 50% (95% CI 31-69%), respectively. Real-world data show that the addition of venetoclax to FLAG-IDA protocol is effective in patients with high-risk AML, most notably in the post-HCT relapse setting. Prophylaxis and surveillance for infections are crucial.

Repeat biopsy in relapsed or refractory diffuse large B cell lymphoma: a nationwide survey and retrospective study.

Almost half of patients with diffuse large B-cell lymphoma (DLBCL) have relapsed/refractory (R/R) disease after frontline immunochemotherapy. Although guidelines recommend histological confirmation of R/R disease, repeat biopsies are not always performed. We conducted a two-part study: a nationwide case-vignette survey among treating hematologists, and a single center retrospective analysis. In the survey part, all 64 participating physicians opted not to perform a repeat biopsy in at least one scenario, more often in refractory cases. In the retrospective part, 116 episodes of R/R aNHL among 61 patients were identified. Repeat biopsy was not performed in 72%, more often in refractory episodes, mostly due to low likelihood of alternative diagnoses or problematic location for biopsy. Our study suggests that many patients do not undergo repeat biopsy in R/R DLBCL, especially in refractory cases. Future studies and recommendations should address the necessity of repeat biopsy, according to patient and disease related characteristics.

Humoral serological response to the BNT162b2 vaccine after allogeneic haematopoietic cell transplantation.

OBJECTIVES: To assess the humoral immune response to the BNT162b2 vaccine after allogeneic haematopoietic cell transplantation (HCT). METHODS: This is a prospective cohort study. The SARS-CoV-2 IgGII Quant (Abbott©) assay was performed 4-6 weeks after the second BNT162b2 vaccine for quantitative measurement of anti-spike antibodies. RESULTS: The cohort included 106 adult patients. Median time from HCT to vaccination was 42 (range 4-439) months. Overall, 15/106 (14%, 95% confidence interval (CI) 7-21%) were seronegative despite vaccination, 14/52 patients on immunosuppression (27%, 95%CI 19-35%) compared to only 1/54 patients off immunosuppression (1.8%, 95%CI 1-4%) (p 0.0002). The proportion of seronegative patients declined with time; it was 46% (6/13) during the first year, 12.5% (3/24) during the second year and 9% (6/69) beyond 2 years from transplant. Patients with acute graft-versus-host disease (GVHD) (odds ratio (OR) 3.3, 95%CI 0.97-11.1, p 0.06) and moderate to severe chronic GVHD (OR 5.9, 95%CI 1.2-29, p 0.03) were more likely to remain seronegative. Vaccination was well tolerated by most patients. However, 7% (7/106) reported that GVHD-related symptoms worsened within days following vaccination. CONCLUSION: A significant proportion of allogeneic HCT recipients receiving immunosuppression demonstrated an inadequate humoral response to the BNT162b2 vaccine. These patients should be recognized and instructed to take appropriate precautions. Recipients who were off immunosuppression had a humoral response that was comparable to that of the general population.

T-Lymphoblastic Leukemia/Lymphoma and Thymoma: A Case Report and Review of the Literature of a Rare Association.

The co-occurrence of thymoma and T-lymphoblastic lymphoma/leukemia is an extremely rare but previously reported association that poses a diagnostic and therapeutic challenge. We describe a 67-year-old patient with long-standing untreated B1 thymoma that presented with constitutional symptoms and a painless soft tissue mass on the right chest wall. Pathological analysis of the biopsy from the mass demonstrated T-lymphoblastic leukemia/lymphoma. The patient went through a complicated course, was refractory to several lines of therapy, and eventually underwent allogeneic hematopoietic stem cell transplantation in complete remission from a matched related donor. The association between thymoma and malignant neoplasms has been described in the literature, most notably with colorectal adenocarcinoma and thyroid cancer. Thymoma-associated leukemia is, however, extremely unusual, with limited reports in the literature. Distinguishing between thymoma and leukemia can be challenging and often requires meticulous diagnostic efforts. For patients with a past history of thymoma, awareness of this particular association should be bared in mind to allow earlier diagnosis and therapy.