Elizabeth de Kort

Background/Objectives: Multiple Myeloma (MM) is a hematologic malignancy caused by clonally expanded plasma cells that produce a monoclonal immunoglobulin (M-protein), a personalized biomarker. Recently, we developed an ultra-sensitive mass spectrometry method to quantify minimal residual disease (MS-MRD) by targeting unique M-protein peptides. Therapeutic antibodies (t-Abs), key in MM treatment, often lead to deep and long-lasting responses. However, t-Abs can significantly decrease the total polyclonal immunoglobulin (Ig) levels which require supplemental IgG infusion. Here, we demonstrate the simultaneous monitoring of M-proteins, t-Abs, and polyclonal Ig-titers using an untargeted mass spectrometry assay, offering a comprehensive view of therapy response. Methods: Sera collected between 2013 and 2024 from four patients and cerebrospinal fluid (CSF) from one patient who received various t-Abs were analyzed with MS-MRD. M-protein sequences were obtained with a multi-enzyme de novo protein sequencing approach. Unique peptides for M-proteins and t-Abs were selected based on linearity, sensitivity, and slope coefficient in serial dilutions. Ig constant regions were monitored using isotype-specific peptides. Results: The MS-MRD multiplex analysis provided detailed information on drug concentrations and therapy response kinetics. For example, in two patients with refractory disease over five lines of therapy, the MS-MRD analysis showed that the deepest responses were achieved with bispecific t-Ab (teclistamab) treatment. M-protein and t-Ab were also detectable in the CSF of one patient with MS-MRD. Conclusions: This proof-of-concept study shows that the multiplex monitoring of the M-protein, any t-Ab combination, and all Ig-isotypes within one mass spectrometry run is feasible and provides unique insight into therapy response kinetics.

Isavuconazole is a relatively new antifungal agent indicated for the management of various invasive fungal diseases (IFDs), including invasive aspergillosis. Information on real-world experience with isavuconazole is scarce. This retrospective observational study aimed to describe the usage of isavuconazole in clinical practice with an in-depth evaluation of individual isavuconazole exposure. Patients treated with isavuconazole were evaluated based on retrospective data, including therapeutic drug monitoring (TDM) data and efficacy and safety data. Additionally, we calculated the individual isavuconazole exposure described by the average AUC₂₄ over the first 7 days of treatment by means of non-linear mixed-effects modelling and compared this with the currently desired lower target AUC of 60 mg·h/L. Ninety-nine patients treated with isavuconazole were evaluated. In our real-life cohort, isavuconazole was often deployed off-label in patients with non-classical host factors and infections with non-Aspergillus and non-Mucorales species. Isavuconazole was most often chosen for its safety profile, even after prior triazole treatment with manifestations of toxicity. TDM and subsequent dosage adjustments were frequently performed. The individual average AUC₂₄ over 7 days was above 60 mg·h/L in 29 out of 77 (37.7%) patients. This overview provides practical insights that can aid clinicians in the management of their patients with IFD. Our study shows that isavuconazole was used in a diverse patient population and was well tolerated overall. Individual isavuconazole exposure reflected by the average AUC₂₄ over the first 7 days of treatment was generally low and variable. Dosage adjustments following TDM were frequently performed. Our experience shows that isavuconazole is a feasible alternative after prior azole treatment.

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.

Objectives: Patients receiving remission induction therapy for acute myeloid leukaemia (AML) are at high risk of developing invasive fungal disease (IFD). Newer therapies with targeted antileukemic agents and the emergence of azole resistance pose a challenge to the strategy of primary antifungal prophylaxis. We report the experience of a diagnostic-driven care pathway (DCP) for the management of IFD in these patients, using only culture-directed mould inactive prophylaxis. Methods: Retrospectively, we used a single-centre study of consecutive patients receiving intensive chemotherapy for myeloid malignancies between 2014 and 2021. DCP consisted of serial cultures and serum galactomannan (sGM) screening, CT imaging, and bronchoscopy to direct targeted antifungal treatment. IFD was classified according to the 2020 EORTC/MSGERC criteria. Results: A total of 192 patients with myeloid malignancies received 300 courses of intensive chemotherapy. There were 14 cases of invasive yeast infections and 18 of probable/proven invasive mould disease (IMD). The incidence of probable/proven IMD during the first cycle of remission-induction chemotherapy was 4.6% (n = 9). sGM remained negative in all cases of invasive aspergillosis (IA), with positive mycology findings in bronchoalveolar lavage. All-cause mortality was 9.4% (n = 18) 100 days after starting chemotherapy and was comparable between patients with or without IFD. The fungal-related mortality was 1% (n = 2). Conclusion: Diagnostic-driven based management without universal mould active prophylaxis is a feasible strategy in the management of IFD and limits unnecessary antimould treatment during intensive chemotherapy. The poor performance of serial serum galactomannan screening in detecting IA warrants further investigation.

We report a 53-year-old man who presented with acute renal failure. His medical history revealed a spondyloarthropathy, for which secukinumab was started recently, and a monoclonal gammopathy of unknown significance. Kidney function deteriorated despite the withdrawal of secukinumab and dialysis was started. In the serum, type 1 cryoglobulins were present and a kidney biopsy showed ischaemic glomeruli, with thrombosis of the larger interlobular arteries. Other causes of thrombotic microangiopathy were excluded. Bone marrow immunophenotyping showed 1% monoclonal plasma cells. A diagnosis of monoclonal gammopathy of renal significance was made. Haematological treatment resulted in haematological and renal response.

Invasive fungal diseases (IFDs) often represent complicated infections in complex patient populations. The Center of Expertise in Mycology Radboudumc/CWZ (EMRC) organizes a biweekly multidisciplinary mycology meeting to discuss patients with severe fungal infections and to provide comprehensive advice regarding diagnosis and treatment. Here, we describe the patient population discussed at these meetings during a one-year period with regards to their past medical history, diagnosis, microbiological and other diagnostic test results and antifungal therapy. The majority of patients discussed were adults (83.1%), 62.5% of whom suffered from pulmonary infections or signs/symptoms, 10.9% from otorhinolaryngeal infections and/or oesophagitis, 9.4% from systemic infections and 9.4% from central nervous system infections. Among children, 53.8% had pulmonary infections or signs/symptoms, 23.1% systemic fungal infections and 23.1% other, miscellaneous fungal infections. 52.5% of adult patients with pulmonary infections/symptoms fulfilled diagnostic criteria for chronic pulmonary aspergillosis (CPA). Culture or polymerase chain reaction (PCR) demonstrated fungal pathogens in 81.8% of patients, most commonly Aspergillus. A multidisciplinary mycology meeting can be a useful addition to the care for patients with (I)FDs and can potentially aid in identifying healthcare and research needs regarding the field of fungal infections. The majority of patients discussed at the multidisciplinary meetings suffered from pulmonary infections, predominantly CPA.

Baseline chest computed tomography (BCT) in high-risk hematology patients allows for the early diagnosis of invasive pulmonary aspergillosis (IPA). The distribution of BCT implementation in hematology departments and impact on outcome is unknown. A web-based questionnaire was designed. International scientific bodies were invited. The estimated numbers of annually treated hematology patients, chest imaging timepoints and techniques, IPA rates, and follow-up imaging were assessed. In total, 142 physicians from 43 countries participated. The specialties included infectious diseases (n = 69; 49%), hematology (n = 68; 48%), and others (n = 41; 29%). BCT was performed in 57% (n = 54) of 92 hospitals. Upon the diagnosis of malignancy or admission, 48% and 24% performed BCT, respectively, and X-ray was performed in 48% and 69%, respectively. BCT was more often used in hematopoietic cell transplantation and in relapsed acute leukemia. European centers performed BCT in 59% and non-European centers in 53%. Median estimated IPA rate was 8% and did not differ between BCT (9%; IQR 5–15%) and non-BCT centers (7%; IQR 5–10%) (p = 0.69). Follow-up computed tomography (CT) for IPA was performed in 98% (n = 90) of centers. In high-risk hematology patients, baseline CT is becoming a standard-of-care. Chest X-ray, while inferior, is still widely used. Randomized, controlled trials are needed to investigate the impact of BCT on patient outcome.