Epidemiological Characteristics and Outcome of Viral Respiratory Tract Infections in the First Year After Allogeneic Hematopoietic Cell Transplantation.

Adverse outcomes of viral respiratory tract infections (RTIs) have been reported in recipients of allogeneic hematopoietic cell transplantation. Using a laboratory-developed multiparameter polymerase chain reaction in a consecutive series of 242 patients, we found the highest incidence of viral RTI in the preengraftment phase. The occurrence of multiple episodes of viral RTI or viral pneumonia was significantly associated with a higher hazard of nonrelapse mortality in the first year after transplantation. We observed a 90-day mortality of 19.7% after viral RTI, which was significantly different between patient groups stratified according to the immunodeficiency scoring index.

Superiority trials in invasive aspergillosis: a harsh reality check with the IA-DUET (HOVON502) trial.

The IA-DUET study aimed to compare azole-echinocandin combination with azole monotherapy for invasive aspergillosis. Recruitment was hindered by patient ineligibility, competing studies, and guidelines favoring combination therapy when azole resistance was unknown. The low IA-attributable mortality suggests future trials may benefit from cluster randomization or composite endpoints to enhance efficiency.

Baseline chest computed tomography for diagnosis of invasive aspergillosis in patients with acute myeloid leukaemia treated with intensive chemotherapy: A retrospective single-centre cohort study.

BACKGROUND: Invasive pulmonary aspergillosis (IPA) is a relatively common infection in patients with acute myeloid leukaemia (AML), and is associated with high mortality rates. Optimising early detection is key to reduce the burden of IPA in this population. In this retrospective cohort study, we evaluated the added value of baseline chest CT before start of classical induction chemotherapy. METHODS: Adult patients receiving first-line intensive chemotherapy for AML were included if a baseline chest CT scan was available (±7 days). Data were collected from the electronic health record. IPA was classified using the EORTC/MSGERC 2020 consensus definitions. RESULTS: Between 2015 and 2019, 99 patients were included. During first-line treatment, 29/99 (30%) patients developed a probable IPA. Baseline chest CT was abnormal in 61/99 (62%) and 14/61 (23%) patients had typical radiological signs for IPA. An abnormal scan showed a trend towards higher risk for IPA (hazard ratio (HR): 2.12; 95% CI 0.95-4.84). Ground glass opacities were a strong predictor for developing IPA (HR 3.35: 95% CI 1.61-7.00). No probable/proven IPA was diagnosed at baseline; however, a bronchoalveolar lavage (BAL) at baseline was only performed in seven patients. Twelve-week mortality was higher in patients with IPA (7/26, 27% vs. 5/59, 8%; p = .024). CONCLUSION: Baseline chest CT scan could be an asset in the early diagnosis of IPA and contribute to risk estimation for IPA. In patients with an abnormal baseline CT, performing a BAL should be considered more frequently, and not only in patients with radiological findings typical for IPA.

Clinical Impact of Polymerase Chain Reaction-Based Aspergillus and Azole Resistance Detection in Invasive Aspergillosis: A Prospective Multicenter Study.

BACKGROUND: Invasive aspergillosis (IA) by a triazole-resistant Aspergillus fumigatus is associated with high mortality. Real-time resistance detection will result in earlier initiation of appropriate therapy. METHODS: In a prospective study, we evaluated the clinical value of the AsperGenius polymerase chain reaction (PCR) assay in hematology patients from 12 centers. This PCR assay detects the most frequent cyp51A mutations in A. fumigatus conferring azole resistance. Patients were included when a computed tomography scan showed a pulmonary infiltrate and bronchoalveolar fluid (BALf) sampling was performed. The primary end point was antifungal treatment failure in patients with azole-resistant IA. RESULTS: Of 323 patients enrolled, complete mycological and radiological information was available for 276 (94%), and probable IA was diagnosed in 99/276 (36%). Sufficient BALf for PCR testing was available for 293/323 (91%). Aspergillus DNA was detected in 116/293 (40%) and A. fumigatus DNA in 89/293 (30%). The resistance PCR was conclusive in 58/89 (65%) and resistance detected in 8/58 (14%). Two had a mixed azole-susceptible/azole-resistant infection. In the 6 remaining patients, treatment failure was observed in 1. Galactomannan positivity was associated with mortality (P = .004) while an isolated positive Aspergillus PCR was not (P = .83). CONCLUSIONS: Real-time PCR-based resistance testing may help to limit the clinical impact of triazole resistance. In contrast, the clinical impact of an isolated positive Aspergillus PCR on BALf seems limited. The interpretation of the EORTC/MSGERC PCR criterion for BALf may need further specification (eg, minimum cycle threshold value and/or PCR positive on >1 BALf sample).

Retrospective Multicenter Evaluation of the VirClia Galactomannan Antigen Assay for the Diagnosis of Pulmonary Aspergillosis with Bronchoalveolar Lavage Fluid Samples from Patients with Hematological Disease.

Galactomannan (GM) testing of bronchoalveolar lavage (BAL) fluid samples has become an essential tool to diagnose invasive pulmonary aspergillosis (IPA) and is part of diagnostic guidelines. Enzyme-linked immunosorbent assays (ELISAs) (enzyme immunoassays [EIAs]) are commonly used, but they have a long turnaround time. In this study, we evaluated the performance of an automated chemiluminescence immunoassay (CLIA) with BAL fluid samples. This was a multicenter retrospective study in the Netherlands and Belgium. BAL fluid samples were collected from patients with underlying hematological diseases with a suspected invasive fungal infection. Diagnosis of IPA was based on the 2020 European Organisation for Research and Treatment of Cancer (EORTC)/Mycoses Study Group Education and Research Consortium (MSGERC) consensus definitions. GM results were reported as optical density index (ODI) values. ODI cutoff values for positive results that were evaluated were 0.5, 0.8, and 1.0 for the EIA and 0.16, 0.18, and 0.20 for the CLIA. Probable IPA cases were compared with two control groups, one with no evidence of IPA and another with no IPA or possible IPA. Qualitative agreement was analyzed using Cohen's κ, and quantitative agreement was analyzed by Spearman's correlation. We analyzed 141 BAL fluid samples from 141 patients; 66 patients (47%) had probable IPA, and 56 cases remained probable IPA when the EIA GM result was excluded as a criterion, because they also had positive culture and/or duplicate positive PCR results. Sixty-three patients (45%) had possible IPA and 12 (8%) had no IPA. The sensitivity and specificity of the two tests were quite comparable, and the overall qualitative agreement between EIA and CLIA results was 81 to 89%. The correlation of the actual CLIA and EIA values was strong at 0.72 (95% confidence interval, 0.63 to 0.80). CLIA has similar performance, compared to the gold-standard EIA, with the benefits of faster turnaround because batching is not required. Therefore, CLIA can be used as an alternative GM assay for BAL fluid samples.

Early high antibody titre convalescent plasma for hospitalised COVID-19 patients: DAWn-plasma.

BACKGROUND: Several randomised clinical trials have studied convalescent plasma for coronavirus disease 2019 (COVID-19) using different protocols, with different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralising antibody titres, at different time-points and severities of illness. METHODS: In the prospective multicentre DAWn-plasma trial, adult patients hospitalised with COVID-19 were randomised to 4 units of open-label convalescent plasma combined with standard of care (intervention group) or standard of care alone (control group). Plasma from donors with neutralising antibody titres (50% neutralisation titre (NT50)) ≥1/320 was the product of choice for the study. RESULTS: Between 2 May 2020 and 26 January 2021, 320 patients were randomised to convalescent plasma and 163 patients to the control group according to a 2:1 allocation scheme. A median (interquartile range) volume of 884 (806-906) mL) convalescent plasma was administered and 80.68% of the units came from donors with neutralising antibody titres (NT50) ≥1/320. Median time from onset of symptoms to randomisation was 7 days. The proportion of patients alive and free of mechanical ventilation on day 15 was not different between both groups (convalescent plasma 83.74% (n=267) versus control 84.05% (n=137)) (OR 0.99, 95% CI 0.59-1.66; p=0.9772). The intervention did not change the natural course of antibody titres. The number of serious or severe adverse events was similar in both study arms and transfusion-related side-effects were reported in 19 out of 320 patients in the intervention group (5.94%). CONCLUSIONS: Transfusion of 4 units of convalescent plasma with high neutralising antibody titres early in hospitalised COVID-19 patients did not result in a significant improvement of clinical status or reduced mortality.

Performance of the JF5-Based Galactomannoprotein EIA Compared to the Lateral Flow Device and the Galactomannan EIA in Serum and Bronchoalveolar Lavage Fluid.

Early diagnosis of invasive aspergillosis is an important factor to improve survival but remains challenging. The detection of Aspergillus antigens is included in the consensus case definitions of the European Organization for Research and Treatment of Cancer and the National Institute of Allergy and Infectious Diseases Mycoses Study Group as a criterion of "probable" invasive aspergillosis. JF5, a mouse IgG3 monoclonal antibody detecting an Aspergillus mannoprotein, has already been implemented as a lateral flow device (LFD). Now, also a JF5-based enzyme-linked immunosorbent assay (EIA) is commercialized (Aspergillus specific galactomannoprotein [GP] EIA, Euroimmun Medizinische Labordiagnostika AG). In this study, we analyzed the diagnostic performance of GP in 63 bronchoalveolar lavage fluid (BALf) samples and 224 serum samples and compared it to performance of the galactomannan (GM) (Platelia Aspergillus enzyme immunoassay (EIA) (Bio-Rad, Marnes-la-Coquette, France)) and the JF5-based LFD (AspLFD; OLM Diagnostics, Newcastle Upon Tyne, United Kingdom). The diagnostic performance of GP and GM correlated well with both having high specificity. With an optimized cutoff threshold for positivity of 0.4-deviating from the 0.5 threshold recommended by the manufacturer-sensitivity of GP in serum is not significantly different than that of GM. However, in BALf sensitivity of GP is significantly less than for GM.

Lateral flow assays for diagnosing invasive pulmonary aspergillosis in adult hematology patients: A comparative multicenter study.

Fast diagnosis of invasive pulmonary aspergillosis (IPA) is essential as early adequate therapy improves survival. However, current microbiological methods suffer from a low sensitivity or a long turnaround time, often as a result of batching. Recently, two lateral flow assays for diagnosing IPA have been CE (Conformité Européenne)-marked and commercialized. These assays can be used for fast single sample testing. However, clinical validation and comparative studies are lacking. We therefore sought to evaluate and compare these assays in adult hematology patients. We retrospectively tested 235 bronchoalveolar lavage fluid (BALf) samples of adult hematology patients from four centers using the AspLFD (OLM Diagnostics) and the sona Aspergillus galactomannan LFA (IMMY). Both tests were read out independently by two researchers and by a digital reader. We included 11 patients with proven IPA, 64 with probable IPA, 43 with possible fungal disease, and 117 controls with no signs of IPA. In cases of proven IPA, the performance of both assays was similar. In cases of proven and probable IPA, we found an identical specificity for both assays, but a higher sensitivity (0.83 vs 0.69, P = .008) and a better negative predictive value (0.89 vs 0.82, P = .009) for the LFA. Digital readout improved the diagnostic performance of both tests. In conclusion, both assays showed a good performance for the diagnosis of IPA in BALf from adult hematology patients. Results were further improved by using a digital reader, especially for weakly positive results.

Outpatient parenteral antifungal therapy (OPAT) for invasive fungal infections with intermittent dosing of liposomal amphotericin B.

Triazole resistant A. fumigatus has been documented in many parts of the world. In the Netherlands, incidence is now above 10% and results in the need for long-term parenteral therapy with liposomal amphotericin B (LAmB). The long terminal half-life of LAmB suggests that intermittent dosing could be effective, making the application of outpatient antifungal therapy (OPAT) possible. Here, we report our experience with the use of OPAT for Invasive Fungal Infections (IFI). All adult patients treated with LAmB with a 2 or 3 times weekly administration via the outpatient departments in four academic tertiary care centers in the Netherlands and Belgium since January 2010 were included in our analysis. Patient characteristics were collected, as well as information about diagnostics, therapy dose and duration, toxicity, treatment history and outcome of the IFI. In total, 18 patients were included. The most frequently used regimen (67%) was 5 mg/kg 3 times weekly. A partial response to the daily treatment prior to discharge was confirmed by CT-scan in 17 (94%) of patients. A favorable outcome was achieved in 13 (72%) patients. Decrease in renal function occurred in 10 (56%) cases but was reversible in all and was treatment limiting in one patient only. The 100-day mortality and 1-year mortality after initiation of OPAT were 0% and 6%, respectively. In a selected population, and after confirmation of initial response to treatment, our data support the use of OPAT with LAmB for treatment of IFI in an intermittent dosing regimen.

Point of care aspergillus testing in intensive care patients.

BACKGROUND: Invasive pulmonary aspergillosis (IPA) is an increasingly recognized complication in intensive care unit (ICU) patients, especially those with influenza, cirrhosis, chronic obstructive pulmonary disease, and other diseases. The diagnosis can be challenging, especially in the ICU, where clinical symptoms as well as imaging are mostly nonspecific. Recently, Aspergillus lateral flow tests were developed to decrease the time to diagnosis of IPA. Several studies have shown promising results in bronchoalveolar lavage fluid (BALf) from hematology patients. We therefore evaluated a new lateral flow test for IPA in ICU patients. METHODS: Using left-over BALf from adult ICU patients in two university hospitals, we studied the performance of the Aspergillus galactomannan lateral flow assay (LFA) by IMMY (Norman, OK, USA). Patients were classified according to the 2008 EORTC-MSG definitions, the AspICU criteria, and the modified AspICU criteria, which incorporate galactomannan results. These internationally recognized consensus definitions for the diagnosis of IPA incorporate patient characteristics, microbiology and radiology. The LFA was read out visually and with a digital reader by researchers blinded to the final clinical diagnosis and IPA classification. RESULTS: We included 178 patients, of which 55 were classified as cases (6 cases of proven and 26 cases of probable IPA according to the EORTC-MSG definitions, and an additional 23 cases according to the modified AspICU criteria). Depending on the definitions used, the sensitivity of the LFA was 0.88-0.94, the specificity was 0.81, and the area under the ROC curve 0.90-0.94, indicating good overall test performance. CONCLUSIONS: In ICU patients, the LFA performed well on BALf and can be used as a rapid screening test while waiting for other microbiological results.

High-dose posaconazole for azole-resistant aspergillosis and other difficult-to-treat mould infections.

BACKGROUND: Oral follow-up therapy is problematic in moulds with reduced azole-susceptibility, such as azole-resistant Aspergillus fumigatus infection. Currently, only intravenous liposomal amphotericin B (L-AmB) is advocated by guidelines for the treatment of azole-resistant aspergillosis infections. Preclinical research indicates that high-dose posaconazole (HD-POS) might be a feasible option provided that high drug exposure (ie POS serum through levels >3 mg/L) can be achieved and is safe. OBJECTIVES: To describe our experience with the use of oral HD-POS as treatment strategies for patients infected with pathogens with a POS MIC close to the clinical breakpoint. PATIENTS/METHODS: We review evidence supporting the use of HD-POS and describe our experience on safety and efficacy in 16 patients. In addition, we describe the adverse events (AE) observed in 25 patients with POS concentrations at the higher end of the population distribution during treatment with the licensed dose. RESULTS: Sixteen patients were treated intentionally with HD-POS for voriconazole-resistant invasive aspergillosis (7/16), mucormycosis (4/16), salvage therapy for IA (4/16) and IA at a sanctuary site (spondylodiscitis) in 1. Grade 3-4 AEs were observed in 6, and all of them were considered at least possibly related. Grade 3-4 AEs were observed in 5 of the 25 patients with spontaneous high POS serum through levels considered at least possibly related using Naranjo scale. CONCLUSIONS: High-dose posaconazole is a treatment option if strict monitoring for both exposure and for AE is possible.

Voriconazole Resistance and Mortality in Invasive Aspergillosis: A Multicenter Retrospective Cohort Study.

BACKGROUND: Triazole resistance is an increasing problem in invasive aspergillosis (IA). Small case series show mortality rates of 50%-100% in patients infected with a triazole-resistant Aspergillus fumigatus, but a direct comparison with triazole-susceptible IA is lacking. METHODS: A 5-year retrospective cohort study (2011-2015) was conducted to compare mortality in patients with voriconazole-susceptible and voriconazole-resistant IA. Aspergillus fumigatus culture-positive patients were investigated to identify patients with proven, probable, and putative IA. Clinical characteristics, day 42 and day 90 mortality, triazole-resistance profiles, and antifungal treatments were investigated. RESULTS: Of 196 patients with IA, 37 (19%) harbored a voriconazole-resistant infection. Hematological malignancy was the underlying disease in 103 (53%) patients, and 154 (79%) patients were started on voriconazole. Compared with voriconazole-susceptible cases, voriconazole resistance was associated with an increase in overall mortality of 21% on day 42 (49% vs 28%; P = .017) and 25% on day 90 (62% vs 37%; P = .0038). In non-intensive care unit patients, a 19% lower survival rate was observed in voriconazole-resistant cases at day 42 (P = .045). The mortality in patients who received appropriate initial voriconazole therapy was 24% compared with 47% in those who received inappropriate therapy (P = .016), despite switching to appropriate antifungal therapy after a median of 10 days. CONCLUSIONS: Voriconazole resistance was associated with an excess overall mortality of 21% at day 42 and 25% at day 90 in patients with IA. A delay in the initiation of appropriate antifungal therapy was associated with increased overall mortality.

Diagnosing Invasive Pulmonary Aspergillosis in Hematology Patients: a Retrospective Multicenter Evaluation of a Novel Lateral Flow Device.

Invasive pulmonary aspergillosis (IPA) is a potentially lethal infection in patients with hematological diseases or following allogeneic stem cell transplantation. Early diagnosis is essential, as delayed treatment results in increased mortality. Recently, a lateral flow device (LFD) for the diagnosis of IPA was CE marked and made commercially available by OLM Diagnostics. We retrospectively analyzed bronchoalveolar lavage fluid (BALf) collected from adult hematology patients from 4 centers in The Netherlands and Belgium. Galactomannan was retested in all samples. All samples were applied to an LFD and read out visually by two independent researchers blinded to the diagnosis of the patient. All samples were also read out using a digital reader. We included 11 patients with proven IPA, 68 patients with probable IPA, 44 patients with possible IPA, and 124 patients with no signs of IPA (controls). In cases of proven IPA versus controls, sensitivity and specificity were 0.82 and 0.86 for visual readout and 0.82 and 0.96 for digital readout, respectively. When comparing patients with proven and probable IPA as cases versus controls, sensitivity and specificity were found to be 0.71 and 0.86, respectively. When excluding serum and BALf galactomannan as mycological criteria from the 2008 European Organization for Research and Treatment of Cancer Invasive Fungal Infections Cooperative Group (EORTC)/Mycoses Study Group of the National Institute of Allergy and Infectious Diseases (MSG) consensus definitions, the LFD was less specific than galactomannan when comparing subjects with proven and probable IPA to controls (0.86 versus 0.96; P = 0.005) but had similar sensitivity (0.76 versus 0.85; P = 0.18). In conclusions, in this large study of the CE-marked LFD in BALf from hematology patients, the LFD had a good performance for the diagnosis of IPA.

Prevalence of voriconazole-resistant invasive aspergillosis and its impact on mortality in haematology patients.

BACKGROUND: Increasing resistance of Aspergillus fumigatus to triazoles in high-risk populations is a concern. Its impact on mortality is not well understood, but rates from 50% to 100% have been reported. OBJECTIVES: To determine the prevalence of voriconazole-resistant A. fumigatus invasive aspergillosis (IA) and its associated mortality in a large multicentre cohort of haematology patients with culture-positive IA. METHODS: We performed a multicentre retrospective study, in which outcomes of culture-positive haematology patients with proven/probable IA were analysed. Patients were stratified based on the voriconazole susceptibility of their isolates (EUCAST broth microdilution test). Mycological and clinical data were compared, along with survival at 6 and 12 weeks. RESULTS: We identified 129 A. fumigatus culture-positive proven or probable IA cases; 103 were voriconazole susceptible (79.8%) and 26 were voriconazole resistant (20.2%). All but one resistant case harboured environment-associated resistance mutations in the cyp51A gene: TR34/L98H (13 cases) and TR46/Y121F/T289A (12 cases). Triazole monotherapy was started in 75.0% (97/129) of patients. Mortality at 6 and 12 weeks was higher in voriconazole-resistant cases in all patients (42.3% versus 28.2%, P = 0.20; and 57.7% versus 36.9%, P = 0.064) and in non-ICU patients (36.4% versus 21.6%, P = 0.16; and 54.4% versus 30.7%; P = 0.035), compared with susceptible ones. ICU patient mortality at 6 and 12 weeks was very high regardless of triazole susceptibility (75.0% versus 66.7%, P = 0.99; and 75.0% versus 73.3%, P = 0.99). CONCLUSIONS: A very high prevalence of voriconazole resistance among culture-positive IA haematology patients was observed. The overall mortality at 12 weeks was significantly higher in non-ICU patients with voriconazole-resistant IA compared with voriconazole-susceptible IA.

The diagnosis and treatment of invasive aspergillosis in Dutch haematology units facing a rapidly increasing prevalence of azole-resistance. A nationwide survey and rationale for the DB-MSG 002 study protocol.

Patients with haematological malignancies are at risk for invasive fungal diseases (IFD). A survey was conducted in all Dutch academic haematology centres on their current diagnostic, prophylactic and therapeutic approach towards IFD in the context of azole-resistance. In all 8 centres, a haematologist and microbiologist filled in the questionnaire that focused on different subgroups of haematology patients. Fungal prophylaxis during neutropaenia was directed against Candida and consisted of fluconazole and/or amphotericin B suspension. Mould-active prophylaxis was given to acute myeloid leukaemia patients during chemotherapy in 2 of 8 centres. All centres used azole prophylaxis in a subset of patients with graft-versus-host disease. A uniform approach towards the diagnosis and treatment of IFD and in particular azole-resistant Aspergillus fumigatus was lacking. In 2017, all centres agreed to implement a uniform diagnostic and treatment algorithm regarding invasive aspergillosis with a central role for comprehensive diagnostics and PCR-based detection of azole-resistance. This study (DB-MSG 002) will re-evaluate this algorithm when 280 patients have been treated. A heterogeneous approach towards antifungal prophylaxis, diagnosis and treatment was apparent in the Netherlands. Facing triazole-resistance, consensus was reached on the implementation of a uniform diagnostic approach in all 8 centres.

Diagnostic Value of Microbial Cell-free DNA Sequencing for Suspected Invasive Fungal Infections: A Retrospective Multicenter Cohort Study.

Background: An early diagnosis and treatment of invasive fungal disease (IFD) is associated with improved outcome, but the moderate sensitivity of noninvasive diagnostic tests makes this challenging. Invasive diagnostic procedures such as bronchoalveolar lavage (BAL) have a higher yield but are not without risk. The detection and sequencing of microbial cell-free DNA (mcfDNA) may facilitate a noninvasive diagnosis. Materials: In a prospective observational study, we collected plasma in the 120 hours preceding or following a BAL in patients with hematological malignancies suspected for a pulmonary IFD. The EORTC/MSGERC2020 criteria were used for IFD classification. Sequencing was performed by Karius (Redwood City, CA) using their Karius Test (KT) on plasma and a "research use only test" on BAL fluid if available. Cases with a probable/proven IFD were identified based on standard diagnostic tests on serum and BAL (microscopy, polymerase chain reaction, galactomannan, culture) and used to calculate the sensitivity, specificity, and additional diagnostic value of the KT. Results: Of 106 patients enrolled, 39 (37%) had a proven/probable invasive aspergillosis, 7 (7%) a non-Aspergillus IFD, and 4 (4%) a mixed IFD. The KT detected fungal mcfDNA in 29 (28%) patients. Compared with usual diagnostic tests, the sensitivity and specificity were 44.0% (95% confidence interval [CI], 31.2-57.7) and 96.6% (95% CI, 88.5%-99.1%). Sensitivity of the KT was higher in non-Aspergillus IFD (Mucorales:2/3, Pneumocystis jirovecii: 3/5). On BAL, the sensitivity was 72.2% (95% CI, 62.1-96.3), and specificity 83.3% (95% CI, 49.1-87.5). Conclusions: Sequencing of mcfDNA may facilitate a noninvasive diagnosis of IFD in particular non-Aspergillus IFD. However, on plasma and similar to currently available diagnostics, it cannot be used as a "rule-out" test.

Immunologic Monitoring after Allogeneic Stem Cell Transplantation: T-SPOT.CMV and QuantiFERON-CMV, Are They the Same?

Despite prophylactic and preemptive strategies, cytomegalovirus (CMV) reactivation and disease remains major concerns after allogeneic hematopoietic stem cell transplantation (allo-HSCT). In recent years, immunologic monitoring using CMV commercially available IFN-γ release assays (IGRAs) has gained interest to better risk-stratify immunocompromised patients or to guide prophylactic therapy. CMV-IGRA can quantify CMV cell-mediated immunity by measuring the IFN-γ that is released by CD4+ and CD8+ T lymphocytes in the presence of CMV antigens. However, the 2 most widely used CMV-IGRAs, T-SPOT.CMV and QuantiFERON-CMV, had not yet been compared in the setting of an allo-HSCT. In the present study, we performed a method comparison between T-SPOT.CMV and QuantiFERON-CMV at 28 days and 100 days post-allo-HSCT, and to assess predictive values of both tests for CMV reactivation. Twenty-seven patients were included in a bicentric prospective trial. Samples were obtained on days +28 and +100 post-allo-HSCT, and patients' clinical information was collected up to day +270 post-HSCT. Comparisons of methods were performed using Cohen's κ. On day +28 (n = 26) post-allo-HSCT, T-SPOT.CMV yielded 3 positive test results and QuantiFERON-CMV yielded 2 positive results. On day +100 (n = 24), T-SPOT.CMV produced 7 positive test results, and QuantiFERON-CMV produced 9. One discordant result was obtained at day +28 (n = 26), and 6 discordant results were obtained at day +100 (n = 24). Method comparison showed a strong agreement on day +28 (κ = .780; 95% confidence interval [CI], .366 to 1.000) but only a moderate agreement on day +100 (κ = .442; 95% CI, .070 to .814) and in pooled data from both time points (κ = .578; 95% CI, .300-.856). Four clinically significant CMV infections (CS-CMVi) were observed, all occurring after discontinuation of letermovir prophylaxis. None of those 4 patients had a positive result with either test at day +100 (or day +28). Thus, the negative predictive value (NPV) and sensitivity were very high, at 100% for both tests measured at day +100. Positive predictive values (PPVs) and specificity were considerably lower at day +100 (T-SPOT.CMV: PPV, 23.5%; specificity, 35%; QuantiFERON-CMV: PPV, 26.7%; specificity, 45%). T-SPOT.CMV and QuantiFERON-CMV had only moderate agreement (at day +100) after allo-HSCT. Although these IGRAs are very promising, as shown by their very high NPVs for protection against CS-CMVi, they are not interchangeable. Future research should stipulate which IGRA was used, and future guidelines preferably should be assay-specific. As QuantiFERON-CMV still lacks a large post-allo-HSCT validation study, the moderate agreement with T-SPOT.CMV poses a significant hurdle in the routine implementation of this test.