Utility of Bronchoalveolar Lavage for the Diagnosis and Management of COVID-19 in Patients With Cancer.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) on nasopharyngeal swab (NPS), remains the most reliable and practical test to diagnose coronavirus disease 2019 (COVID-19). Current literature is sparse regarding the rates of discordance between NPS and bronchoalveolar lavage (BAL) in patients with cancer. METHODS: We conducted a retrospective cohort study of adult patients with cancer who had BAL samples tested for SARS-CoV-2 at a comprehensive cancer center. Patients without NPS PCR for SARS-CoV-2 before BAL were excluded. RESULTS: In a cohort of 345 patients, 12% and 17% tested positive for SARS-CoV-2 on NPS and BAL, respectively. There was a 6.3% NPS-/BAL+ discordance rate and a 9.5% NPS+/BAL- discordance rate. Patients with lymphoma (adjusted odds ratio [aOR] = 4.06; P = .007) and Hispanic patients (aOR = 3.76; P = .009) were more likely to have NPS-/BAL+ discordance on multivariate analysis. Among patients with NPS- /BAL- for SARS-CoV-2, an alternate infectious (23%) and a noninfectious etiology (16%) were identified in BAL. CONCLUSIONS: Our discordance rates between NPS and BAL were sufficient to recommend BAL in certain patients with cancer with a high clinical suspicion of COVID-19. BAL has value in identifying alternative etiologies of illness in patients with suspected or confirmed COVID-19.

Impact of Checkpoint Inhibitor Immunotherapy, Primarily Pembrolizumab, on Infection Risk in Patients With Advanced Lung Cancer: A Comparative Retrospective Cohort Study.

BACKGROUND: Checkpoint inhibitor (CPI) immunotherapy has revolutionized cancer treatment. However, immune-related adverse events and the risk of infections are not well studied. To assess the infectious risk of CPIs, we evaluated the incidence of infections in lung cancer patients treated with CPIs plus conventional chemotherapy (CC) vs CC alone. METHODS: We performed a retrospective comparative study of patients with advanced non-small cell lung cancer who received CPIs combined with CC and those treated with CC alone at our institution during January 2016 to February 2019. We compared clinical characteristics, treatments, and outcomes including infection rate and mortality between the groups. RESULTS: We identified 123 patients for the CPI group and 147 patients for the control (CC) group. Eighteen patients (15%) in the CPI group and 33 patients (22%) in the control group developed infections (P = .1). Pneumonia was the most common infection encountered in both groups. Urinary tract infection was higher in the CC group (40%) than in the CPI group (9%) (P = .01). On multivariable analysis, chronic obstructive pulmonary disease (P = .024), prior use of corticosteroids (P = .021), and neutropenia (P < .001) were independent risk factors for infection and severe infection requiring hospital admission. Chronic kidney disease (P = .02), prior cancer treatment (P = .023), and neutropenia (P < .0001) were identified as independent risk factors for all-cause mortality. CONCLUSIONS: Lung cancer patients treated with CPIs combined with CC have a comparable risk of infection to those treated with CC alone, although there is a trend towards fewer infections in those given CPIs, particularly when it comes to urinary tract infections.

Allogeneic BK Virus-Specific T Cells for Progressive Multifocal Leukoencephalopathy.

JC virus, the cause of progressive multifocal leukoencephalopathy (PML), and the BK virus are genetically similar and share sequence homology in immunogenic proteins. We treated three immunosuppressed patients with PML with ex vivo-expanded, partially HLA-matched, third-party-produced, cryopreserved BK virus-specific T cells. The immunosuppression in these patients was due to the conditioning regimen for cord-blood transplantation in one patient, a myeloproliferative neoplasm treated with ruxolitinib in another, and acquired immunodeficiency syndrome in the third. After T-cell infusion in two of the patients, alleviation of the clinical signs and imaging features of PML was seen and JC virus in the cerebrospinal fluid (CSF) cleared. The other patient had a reduction in JC viral load and stabilization of symptoms that persisted until her death 8 months after the first infusion. Two of the patients had immune reconstitution syndrome. Donor-derived T cells were detected in the CSF after infusion. (Funded by the M.D. Anderson Cancer Center Moon Shots Program and the National Institutes of Health; ClinicalTrials.gov number, NCT02479698 .).

Hematopoietic recovery and immune reconstitution after axicabtagene ciloleucel in patients with large B-cell lymphoma.

Chimeric antigen receptor (CAR) T-cell therapy targeting CD19 may be associated with long-term adverse effects such as cytopenia and immune deficiency. In order to characterize these late events, we analyzed 31 patients with relapsed or refractory large B-cell lymphoma treated with axicabtagene ciloleucel at our institution on two clinical trials, ZUMA-1 (clinicaltrials gov. Identifier: NCT02348216) and ZUMA-9 (clinicaltrials gov. Identifier: NCT03153462). Complete blood counts, lymphocyte subsets, and immunoglobulin levels were measured serially until month 24 or progression. Fifteen (48%) patients had grade 3-4 cytopenia, including anemia (five, 16%), neutropenia (nine, 29%), or thrombocytopenia (13, 42%) at day 30. Cytopenia at day 30 was not significantly associated with later diagnosis of myelodysplasia. Among patients with ongoing remission, grade 3-4 cytopenia was observed in one of nine (11%) at 2 years. While peripheral CD8+ T cells recovered early, CD4+ T-cell recovery was delayed with a count of <200/mL in three of nine (33%) patients at 1 year and two of seven (29%) at 2 years. Immunoglobulin G levels normalized in five of nine (56%) patients at 2 years. Thirteen (42%) patients developed grade 3-4 infectious complications, including herpes zoster and Pneumocystis jiroveci pneumonia. These results suggest the need for prolonged monitoring and prophylaxis against opportunistic infections in these patients, to improve the longterm safety of axicabtagene ciloleucel therapy.

Clinical presentation and outcomes of non-typhoidal Salmonella infections in patients with cancer.

BACKGROUND: Non-typhoidal Salmonella (NTS) infection is thought to be more severe in cancer patients, but this has not been studied since the development of new cancer therapies, increasing antibiotic resistance and the introduction of new antibiotics. We sought to describe the demographic characteristics, microbiological findings, clinical manifestations, and outcomes of NTS infections in cancer patients at our institution. METHODS: We reviewed microbiology laboratory records and identified patients who had cancer and from whom NTS organisms were recovered between January 1, 2000 and December 31, 2013, at a comprehensive cancer center in Houston, Texas. Descriptive statistics were used to summarize patient characteristics, clinical presentation and outcomes. RESULTS: We identified 110 isolates from 82 patients with 88 episodes of NTS infection (including five relapses [6%] in four patients, and two consecutive episodes in one patient). Fifty-five patients (67%) had hematologic malignancies. Most NTS isolates were susceptible to the commonly prescribed antimicrobials. Sixty-nine percent of patients had sepsis and one-third had severe sepsis or septic shock. Gastroenteritis, bacteremia, or both were present in 69% of patients, and the rest had focal infection. Mortality at 30 days was low (8%). Relapses occurred only in patients receiving ≤ 10 days of antibiotic therapy. CONCLUSIONS: NTS affects predominantly patients with hematologic malignancies, followed by gastrointestinal and genitourinary cancers. Invasive disease, sepsis, and septic shock are common presentations among admitted patients. Antimicrobial prophylaxis may not prevent NTS infection. Thirty-day mortality and attributable mortality rates were low in our series compared to older case series. Early appropriate antibiotic therapy may have had a role in decreasing mortality. Relapses occurred in patients receiving ≤ 10 days of therapy, suggesting the need for longer duration of antibiotic therapy in cancer patients with uncomplicated NTS infections.

Immune reconstitution and severity of COVID-19 among hematopoietic cell transplant recipients.

Severe acute respiratory syndrome coronavirus 2 can lead to life-threatening coronavirus disease 2019 (COVID-19) infections in patients with hematologic malignancies, particularly among hematopoietic cell transplant (HCT) recipients. We describe two patients with COVID-19 during the pre-engraftment period after HCT and review previous reports of COVID-19 in HCT recipients. Because of significant mortality from COVID-19, primarily after allogeneic HCT, early, preemptive, and optimal directed therapy may improve outcomes and reduce the mortality rate but still needs to be established in clinical trials.

Correction to: Voriconazole-induced periostitis in stem cell transplant patient.

The original version of this article unfortunately contained a mistake.

Active Mycobacterium tuberculosis infection at a comprehensive cancer center, 2006-2014.

BACKGROUND: Morbidity and mortality from Mycobacterium tuberculosis (Mtb) infection remain significant in cancer patients. We evaluated clinical characteristics, management, and outcomes in patients with active Mtb infection at our institution who had cancer or suspicion of cancer. METHODS: We retrospectively examined medical records of all patients with laboratory-confirmed active Mtb infection diagnosed between 2006 and 2014. RESULTS: A total of 52 patients with laboratory-confirmed active Mtb infection were identified during the study period, resulting in an average rate of 6 new cases per year. Thirty-two (62%) patients had underlying cancer, while 20 (38%) patients did not have cancer but were referred to the institution because of suspicion of underlying malignancy. Among patients with cancer, 18 (56%) had solid tumors; 8 (25%) had active hematologic malignancies; and 6 (19%) had undergone hematopoietic-cell transplantation (HCT). Patients with and without cancer were overall similar with the exception of median age (61 years in cancer patients compared to 53 years in noncancer patients). Pulmonary disease was identified in 32 (62%) patients, extrapulmonary disease in 10 (19%) patients, and disseminated disease in 10 (19%) patients. Chemotherapy was delayed in 53% of patients who were to receive such treatment. Eleven patients (all of whom had cancer) died; 3 of these deaths were attributable to Mtb infection. CONCLUSIONS: Although not common, tuberculosis remains an important infection in patients with cancer. Approximately one-third of patients were referred to our institution for suspicion of cancer but were ultimately diagnosed with active Mtb infection rather than malignancy.

Delay of alternative antiviral therapy and poor outcomes of acyclovir-resistant herpes simplex virus infections in recipients of allogeneic stem cell transplant - a retrospective study.

Acyclovir is commonly used to prevent and treat herpes simplex virus (HSV) reactivation after hematopoietic cell transplant (HCT), and only few reports have been published on acyclovir-resistant HSV in HCT recipients. We reviewed the medical records of patients with a microbiologic diagnosis of acyclovir-resistant HSV by plaque reduction test who received an HCT from 2002 through 2014. A total of 4 028 HCTs were performed during the study period, and 18 of the recipients met the diagnostic criteria for acyclovir-resistant HSV. All cases had undergone allogeneic HCTs. Most patients were in the pre-engraftment period or on systemic corticosteroid therapy for graft-versus-host disease (GVHD). The median time between diagnosis and susceptibility testing was 15 days, and antiviral therapy was changed at a median of 27 days. Patients required prolonged therapy (~80 days), and many had serious complications including renal failure and hospitalization. In conclusion, acyclovir-resistant HSV infection is more likely during the period of profound deficit in T-cell-mediated immunity and is associated with significant morbidities. Higher doses of acyclovir prophylaxis might be needed for patients with history of HSV during pre-engraftment or GVHD treatment. In patients who do not respond or progress after 1 week of acyclovir therapy, testing for drug-resistant HSV, and early switch to an alternative antiviral should be considered.

Graft loss attributed to possible transfusion-transmitted ehrlichiosis following cord blood stem cell transplant.

We present a case of possible transfusion-transmitted Ehrlichia chaffeensis infection in a heavily transfused cord blood transplant recipient, resulting in severe infection and graft loss. Transfusion-transmitted, vector-borne infections in immunocompromised individuals can have severe consequences, and should be considered in hospitalized patients receiving blood products with unexplained fever or sepsis.

Burden of human metapneumovirus infections in patients with cancer: Risk factors and outcomes.

BACKGROUND: Human metapneumovirus (hMPV) causes upper and lower respiratory tract infections (URIs and LRIs, respectively) in healthy and immunocompromised patients; however, its clinical burden in patients with cancer remains unknown. METHODS: In a retrospective study of all laboratory-confirmed hMPV infections treated at the authors' institution between April 2012 and May 2015, clinical characteristics, risk factors for progression to an LRI, treatment, and outcomes in patients with cancer were determined. RESULTS: In total, 181 hMPV infections were identified in 90 patients (50%) with hematologic malignancies (HMs), in 57 (31%) hematopoietic cell transplantation (HCT) recipients, and in 34 patients (19%) with solid tumors. Most patients (92%) had a community-acquired infection and presented with URIs (67%), and 43% developed LRIs (59 presented with LRIs and 19 progressed from a URI to an LRI). On multivariable analysis, an underlying HM (adjusted odds ratio [aOR], 3.11; 95% confidence interval [CI], 1.12-8.64; P = .029), nosocomial infection (aOR, 26.9; 95% CI, 2.79-259.75; P = .004), and hypoxia (oxygen saturation [SpO2], ≤ 92%) at presentation (aOR, 9.61; 95% CI, 1.98-46.57; P = .005) were identified as independent factors associated with LRI. All-cause mortality at 30 days from hMPV diagnosis was low (4%), and patients with LRIs had a 10% mortality rate at day 30 from diagnosis; whereas patients with URIs had a 0% mortality rate. CONCLUSIONS: hMPV infections in patients with cancer may cause significant morbidity, especially for those with underlying HM who may develop an LRI. Despite high morbidity and the lack of directed antiviral therapy for hMPV infections, mortality at day 30 from this infection remained low in this studied population. Cancer 2017;123:2329-2337. © 2017 American Cancer Society.

Outcomes of Influenza Infections in Hematopoietic Cell Transplant Recipients: Application of an Immunodeficiency Scoring Index.

Hematopoietic cell transplant (HCT) recipients have lower immune response to influenza vaccination and are susceptible to lower respiratory tract infection (LRI) and death. We determined clinical characteristics and outcomes of laboratory-confirmed influenza, including 2014/H3N2 infection, in 146 HCT recipients. An immunodeficiency scoring index (ISI) was applied to identify patients at high risk for LRI and death. Thirty-three patients (23%) developed LRI and 7 (5%) died within 30 days of diagnosis. Most patients received antiviral therapy (83%); however, only 18% received it within 48 hours of symptom onset. The incidence of LRI was significantly higher in the ISI high-risk group than it was in the low-risk group (P < .001). Receiving early antiviral therapy was associated with a substantial reduction in LRI for all ISI risk groups with the greatest risk reduction observed in the high-risk group. When compared with previous seasons, no significant differences in patient outcomes were observed during the 2014/H3N2 season; however, antiviral therapy was more promptly initiated in the latter season. The ISI that was originally developed for respiratory syncytial virus may help identify HCT recipients at risk for progression to LRI and mortality after influenza infection. These patients should be monitored more closely. Early initiation of antiviral therapy for influenza in HCT recipients, regardless of the ISI risk group, may improve morbidity as well as mortality.

Successful Salvage of Central Venous Catheters in Patients with Catheter-Related or Central Line-Associated Bloodstream Infections by Using a Catheter Lock Solution Consisting of Minocycline, EDTA, and 25% Ethanol.

In cancer patients with long-term central venous catheters (CVC), removal and reinsertion of a new CVC at a different site might be difficult because of the unavailability of accessible vascular sites. In vitro and animal studies showed that a minocycline-EDTA-ethanol (M-EDTA-EtOH) lock solution may eradicate microbial organisms in biofilms, hence enabling the treatment of central line-associated bloodstream infections (CLABSI) while retaining the catheter in situ Between April 2013 and July 2014, we enrolled 30 patients with CLABSI in a prospective study and compared them to a historical group of 60 patients with CLABSI who had their CVC removed and a new CVC inserted. Each catheter lumen was locked with an M-EDTA-EtOH solution for 2 h administered once daily, for a total of 7 doses. Patients who received locks had clinical characteristics that were comparable to those of the control group. The times to fever resolution and microbiological eradication were similar in the two groups. Patients with the lock intervention received a shorter duration of systemic antibiotic therapy than that of the control patients (median, 11 days versus 16 days, respectively; P < 0.0001), and they were able to retain their CVCs for a median of 74 days after the onset of bacteremia. The M-EDTA-EtOH lock was associated with a significantly decreased rate of mechanical and infectious complications compared to that of the CVC removal/reinsertion group, who received a longer duration of systemic antimicrobial therapy. (This study has been registered at ClinicalTrials.gov under registration no. NCT01539343.).

Case-Control Study of Telavancin as an Alternative Treatment for Gram-Positive Bloodstream Infections in Patients with Cancer.

Gram-positive bacterial infections are an important cause of morbidity and death among cancer patients, despite current therapy. In this case-control study, we evaluated the clinical outcomes and safety of telavancin in cancer patients with uncomplicated Gram-positive bloodstream infections (BSIs). Between March 2011 and May 2013, we enrolled cancer patients with uncomplicated Gram-positive BSIs to receive intravenous telavancin therapy for at least 14 days for Staphylococcus aureus and 7 days for other Gram-positive cocci. Patients with baseline creatinine clearance (CLCR) values of >50 ml/min received 10 mg/kg/day of telavancin, and those with CLCR values between 30 and 49 ml/min received 7.5 mg/kg/day. Patients were compared with a retrospective cohort of 39 historical patients with Gram-positive BSIs, matched for underlying malignancy, infecting organism, and neutropenia status, who had been treated with vancomycin. A total of 78 patients were analyzed, with 39 in each group. The most common pathogen causing BSIs was S. aureus (51%), followed by alpha-hemolytic streptococci (23%), Enterococcus spp. (15%), coagulase-negative staphylococci (8%), and beta-hemolytic streptococci (3%). Sixty-two percent of patients had hematological malignancies, and 38% had solid tumors; 51% of the patients were neutropenic. The overall response rate determined by clinical outcome and microbiological eradication at 72 h following the initiation of therapy, in the absence of relapse, deep-seated infections, and/or infection-related death, was better with telavancin than with vancomycin (86% versus 61%; P = 0.013). Rates of drug-related adverse events were similar in the two groups (telavancin, 31%; vancomycin, 23%; P = 0.79), with similar rates of renal adverse events. Telavancin may provide a useful alternative to standard vancomycin therapy for Gram-positive BSIs in cancer patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT01321879.).

Cluster and sporadic cases of herbaspirillum species infections in patients with cancer.

BACKGROUND: Herbaspirillum species are gram-negative Betaproteobacteria that inhabit the rhizosphere. We investigated a potential cluster of hospital-based Herbaspirillum species infections. METHODS: Cases were defined as Herbaspirillum species isolated from a patient in our comprehensive cancer center between 1 January 2006 and 15 October 2013. Case finding was performed by reviewing isolates initially identified as Burkholderia cepacia susceptible to all antibiotics tested, and 16S ribosomal DNA sequencing of available isolates to confirm their identity. Pulsed-field gel electrophoresis (PFGE) was performed to test genetic relatedness. Facility observations, infection prevention assessments, and environmental sampling were performed to investigate potential sources of Herbaspirillum species. RESULTS: Eight cases of Herbaspirillum species were identified. Isolates from the first 5 clustered cases were initially misidentified as B. cepacia, and available isolates from 4 of these cases were indistinguishable. The 3 subsequent cases were identified by prospective surveillance and had different PFGE patterns. All but 1 case-patient had bloodstream infections, and 6 presented with sepsis. Underlying diagnoses included solid tumors (3), leukemia (3), lymphoma (1), and aplastic anemia (1). Herbaspirillum species infections were hospital-onset in 5 patients and community-onset in 3. All symptomatic patients were treated with intravenous antibiotics, and their infections resolved. No environmental source or common mechanism of acquisition was identified. CONCLUSIONS: This is the first report of a hospital-based cluster of Herbaspirillum species infections. Herbaspirillum species are capable of causing bacteremia and sepsis in immunocompromised patients. Herbaspirillum species can be misidentified as Burkholderia cepacia by commercially available microbial identification systems.

Management of HIV infection in patients with cancer receiving chemotherapy.

The optimal antiretroviral therapy (ART) regimen for human immunodeficiency virus (HIV)-infected patients with cancer remains unknown, as clinical trials are lacking and published data are insufficient to guide recommendations. When concomitant use of chemotherapy and ART is anticipated, overlap of toxic effects and drug-drug interactions between chemotherapy and ART may alter the optimal choice of ART. Prospective studies are urgently needed to further define the toxic effects of combined chemotherapy and ART in HIV-positive cancer patients. Such studies should aid the development of guidelines for treatment of this population. For now, clinicians should individualize decisions regarding treatment of HIV according to clinical and laboratory findings, cancer treatment plan (chemotherapy, radiotherapy, or surgery), liver or renal disease, potential adverse drug effects (eg, rash, gastrointestinal intolerance, bone marrow suppression), and patient preference. This review focuses on what infectious disease specialists need to know to select the most appropriate ART regimens for patients receiving chemotherapy.

Incidence density of invasive fungal infections during primary antifungal prophylaxis in newly diagnosed acute myeloid leukemia patients in a tertiary cancer center, 2009 to 2011.

Although primary antifungal prophylaxis (PAP) is routinely administered in patients with acute myeloid leukemia (AML) during remission-induction and consolidation chemotherapy, the impact of PAP on the incidence of invasive fungal infections (IFIs) is not well described. We retrospectively analyzed the incidence of IFIs in 152 patients with AML who had been admitted to a tertiary cancer center between August 2009 and March 2011 and received PAP within 120 days after first remission-induction chemotherapy. We excluded patients who had undergone stem cell transplantation. Patients received a PAP drug with anti-Aspergillus activity during 72% (7,660/10,572) of prophylaxis-days. The incidence of documented IFIs (definite or probable according to revised European Organization for Research and Treatment of Cancer [EORTC] criteria) was 2.0/1,000 prophylaxis-days (95% confidence interval [CI], 1.23 to 3.04). IFIs due to molds were more common than IFIs due to yeasts (1.5/1,000 prophylaxis-days versus 0.4/1,000 prophylaxis-days; P = 0.01). Echinocandin-based PAP (8.6 and 7.1/1,000 prophylaxis-days, respectively) was associated with higher rates of documented IFIs than anti-Aspergillus azoles (voriconazole or posaconazole) (2.4 and 1.1/1,000 prophylaxis-days, respectively) at both 42 days (P = 0.03) and 120 days (P < 0.0001) after first remission-induction chemotherapy. The incidence of overall (documented and presumed) IFIs (P < 0.001), documented IFIs (P < 0.01), and empirical antifungal therapies (P < 0.0001) was higher during the first 42 days than after day 42. Despite the broad use of PAP with anti-Aspergillus activity, IFIs, especially molds, remain a significant cause of morbidity and mortality in AML patients, predominantly during the remission-induction phase. Patients receiving echinocandin-based PAP experienced higher rates of IFIs than did those receiving anti-Aspergillus azoles.

Effectiveness of primary anti-Aspergillus prophylaxis during remission induction chemotherapy of acute myeloid leukemia.

Although antifungal prophylaxis is frequently administered to patients with acute myeloid leukemia (AML) during remission-induction chemotherapy (RIC), its impact on reducing invasive fungal infections (IFIs) outside clinical trials is rarely reported. We performed a retrospective observational study to identify risk factors for development of IFIs (definite or probable, using revised European Organization for Research and Treatment of Cancer [EORTC] criteria) and all-cause mortality in a cohort of 152 AML patients receiving RIC (2009 to 2011). We also compared rates of IFI and mortality in patients who received echinocandin versus anti-Aspergillus azole (voriconazole or posaconazole) prophylaxis during the first 120 days of RIC. In multivariate analysis, clofarabine-based RIC (hazard ratio [HR], 3.5; 95% confidence interval [CI], 1.5 to 8.3; P = 0.004) and echinocandin prophylaxis (HR, 4.6; 95% CI, 1.8 to 11.9; P = 0.002) were independently associated with higher rates of IFI rates during RIC. Subsequent analysis failed to identify any malignancy- or chemotherapy-related covariates linked to echinocandin prophylaxis that accounted for the higher rates of breakthrough IFI. Although the possibility of other confounding variables cannot be excluded, our findings suggest that echinocandin-based prophylaxis during RIC for AML may be associated with a higher risk of breakthrough IFI.

Progressive multifocal leukoencephalopathy after allogeneic bone marrow transplantation for acute myeloid leukemia.

Progressive multifocal leukoencephalopathy (PML) is a rare fatal complication of allogeneic bone marrow transplantation (BMT) resulting from chronic immunosuppression and impaired cellular immunity. This report discusses 2 cases of PML in patients with acute myeloid leukemia after allogeneic BMT. Diagnosis was made based on characteristic brain MRI findings and positive PCR results for John Cunningham virus in the cerebrospinal fluid. Unfortunately, therapeutic options are limited and nearly always result in terminal outcomes. Although immunosuppression is an unavoidable risk of allogeneic BMT, these cases highlight a rare, yet fatal, consequence of prolonged T-cell lymphopenia and impaired cellular immunity after allogeneic BMT in this patient population.