Detection of Scedosporium spp.: Colonizer or pathogen? A retrospective analysis of clinical significance and management in a large tertiary center

Infections with Scedosporium spp. are emerging in the past two decades and are associated with a high mortality rate. Microbiological detection can be associated with either colonization or infection. Evolution from colonization into infection is difficult to predict and clinical management upon microbiological detection is complex. Microbiological samples from 2015 to 2021 were retrospectively analyzed in a single tertiary care center. Classification into colonization or infection was performed upon first microbiological detection. Clinical evolution was observed until July 2023. Further diagnostic procedures after initial detection were analyzed. Among 38 patients with microbiological detection of Scedosporium spp., 10 were diagnosed with an infection at the initial detection and two progressed from colonization to infection during the observation time. The main sites of infection were lung (5/12; 41.6%) followed by ocular sites (4/12; 33.3%). Imaging, bronchoscopy or biopsies upon detection were performed in a minority of patients. Overall mortality rate was similar in both groups initially classified as colonization or infection [30.7% and 33.3%, respectively (P = 1.0)]. In all patients where surgical debridement of site of infection was performed (5/12; 42%); no death was observed. Although death occurred more often in the group without eradication (3/4; 75%) compared with the group with successful eradication (1/8; 12.5%), statistical significance could not be reached (P = 0.053). As therapeutic management directly impacts patients' outcome, a multidisciplinary approach upon microbiological detection of Scedosporium spp. should be encouraged. Data from larger cohorts are warranted in order to analyze contributing factors favoring the evolution from colonization into infection.

Distinct Hodgkin lymphoma subtypes defined by noninvasive genomic profiling

The scarcity of malignant Hodgkin and Reed-Sternberg cells hampers tissue-based comprehensive genomic profiling of classic Hodgkin lymphoma (cHL). By contrast, liquid biopsies show promise for molecular profiling of cHL due to relatively high circulating tumour DNA (ctDNA) levels1-4. Here we show that the plasma representation of mutations exceeds the bulk tumour representation in most cases, making cHL particularly amenable to noninvasive profiling. Leveraging single-cell transcriptional profiles of cHL tumours, we demonstrate Hodgkin and Reed-Sternberg ctDNA shedding to be shaped by DNASE1L3, whose increased tumour microenvironment-derived expression drives high ctDNA concentrations. Using this insight, we comprehensively profile 366 patients, revealing two distinct cHL genomic subtypes with characteristic clinical and prognostic correlates, as well as distinct transcriptional and immunological profiles. Furthermore, we identify a novel class of truncating IL4R mutations that are dependent on IL-13 signalling and therapeutically targetable with IL-4Rα-blocking antibodies. Finally, using PhasED-seq5, we demonstrate the clinical value of pretreatment and on-treatment ctDNA levels for longitudinally refining cHL risk prediction and for detection of radiographically occult minimal residual disease. Collectively, these results support the utility of noninvasive strategies for genotyping and dynamic monitoring of cHL, as well as capturing molecularly distinct subtypes with diagnostic, prognostic and therapeutic potential.

Clinical Relevance of Anti-TNF Antibody Trough Levels and Anti-Drug Antibodies in Treating Inflammatory Bowel Disease Patients

Background and Aims

The majority of patients treated with anti-tumor necrosis factor (TNF) therapy develop anti-drug antibodies (ADAs), which might result in loss of treatment efficacy. Strict guidelines on measuring trough levels (TLs) and ADA in clinical routine do not exist. To provide real-world data, we took advantage of our tertiary inflammatory bowel disease (IBD) center patient cohort and determined indicators for therapeutic drug monitoring (TDM) and actual consequences in patient care.

Methods

We retrospectively collected clinical data of 104 IBD patients treated with infliximab or adalimumab in our IBD clinic. Patients with TL and ADA measurements between June 2015 and February 2018 were included.

Results

The main reason for determining TL was increased clinical disease. Subtherapeutic TLs were found in 33 patients, therapeutic TLs in 33 patients, and supratherapeutic TLs in 38 patients. Adjustments in anti-TNF therapy occurred more frequently (p = 0.01) in patients with subtherapeutic TL (24 of 33 patients; 73%) as compared to patients with therapeutic and supratherapeutic TLs (26 of 71 patients; 37%). No correlation could be found between TL and disease activity (p = 0.16). Presence of ADA was found in 16 patients, correlated with the development of infusion reactions (OR: 10.6, RR: 5.4, CI: 2.9-38.6), and was associated with subtherapeutic TL in 15 patients (93.8%). Treatment adaptations were based on TL and/or ADA presence in 36 of 63 patients.

Conclusions

TDM showed significant treatment adaptations in patients with subtherapeutic TL. Conversely, in patients with therapeutic and supratherapeutic TLs, reasons for adaptations were based on considerations other than TL, such as clinical disease activity. Further studies should focus on decision-making in patients presenting with supratherapeutic TL in remission.

Long-Term Follow-Up of Antibody Titers Against Measles, Mumps, and Rubella in Recipients of Allogenic Hematopoietic Cell Transplantation

Outbreaks of viral infections, such as measles, are regularly observed and pose a serious threat to recipients of allogeneic hematopoietic cell transplantation (HCT). The questions of how long cellular and humoral protective host immunity persists, and whether donor immunity can be transferred has not been clarified. Here we present a retrospective analysis of humoral immunity-serial antibody titers against measles, mumps, and rubella-in 331 patients who underwent allogeneic HCT at our single center between 2002 and 2015. Associations between the loss of protective antibody levels and clinical patient characteristics and transplantation parameters were examined. In general, antibody protection against measles persisted longer, with 72% of patients maintaining sufficient titers at 5 years post-HCT even without revaccination, while at that time only 65% and 50% of patients had protective immunity against rubella and mumps, respectively. The great majority of donors were seropositive for all 3 viruses; however, it appeared that donor humoral immunity could not be transferred and had no impact on post-HCT serostatus. Rather, the most relevant factor for persistent protective antibody titers against measles and rubella was whether patients were born before the introduction of the respective vaccine and thus were immunized by the wild-type disease-inducing virus instead of the vaccine. Moreover, the presence of moderate and severe chronic graft-versus-host disease (GVHD) was associated with more rapid loss of immune protection. In contrast, underlying disease, intensity of the conditioning regimen, use of antithymocyte globulin, age, and graft source had no influence on antibody titers. Overall, our findings suggest that the majority of antibodies against measles, mumps, and rubella originate from residual host cells, whereas donor immune status appears to have no influence on antibody protection post-HCT.

Targeting CD157 in AML using a novel, Fc-engineered antibody construct

Antibody-based immunotherapy represents a promising strategy to eliminate chemorefractory leukemic cells in acute myeloid leukemia (AML). In this study, we evaluated a novel Fc-engineered antibody against CD157 (MEN1112) for its suitability as immunotherapy in AML. CD157 was expressed in 97% of primary AML patient samples. A significant, albeit lower expression level of CD157 was observed within the compartment of leukemia-initiating cells, which are supposed to be the major source of relapse. In healthy donor bone marrow, CD157 was expressed on CD34⁺ cells. In ex vivo assays, MEN1112 triggered natural killer (NK) cell-mediated cytotoxicity against AML cell lines and primary AML cells. Compared to its parental analogue, the Fc-engineered antibody exhibited higher antibody dependent cellular cytotoxicity responses. Using NK cells from AML patients, we observed heterogeneous MEN1112-mediated cytotoxicity against AML cells, most likely due to well-documented defects in AML-NK cells and corresponding inter-patient variations in NK cell function. Cytotoxicity could not be correlated to the time after completion of chemotherapy. In summary, we could demonstrate that CD157 is strongly expressed in AML. MEN1112 is a promising antibody construct that showed high cytotoxicity against AML cells and warrants further clinical testing. Due to variability in NK-cell function of AML patients, the time of application during the course of the disease as well as combinatorial strategies might influence treatment results.

Apolipoproteins and immunohistological differentiation of cells in the arterial wall of kidneys in transplant arteriopathy. Morphological parallels with atherosclerosis

22 nephrectomy specimens of renal allografts in chronic rejection after periods between 3 and 96 months, were studied immunohistologically. Various cell types in the arterial wall were characterized with antibodies specific against different cells of the mononuclear phagocyte system, against smooth muscle cells, and against differentiating lymphoid cells. In addition, the metabolism of lipoproteins was investigated using appropriate antibodies against several apolipoproteins. Subendothelial plaques of foam cells were found to consist of macrophages in foamy transformation. At the stage of intimal fibrosis the smooth muscle cells are more prominent. Lymphatic infiltration consists almost exclusively of T-lymphocytes. Apolipoprotein analysis reveals deposits of Apo A1, A2 and B1, most of them extracellular. According to these results, it is not only immunologic factors that are involved in arterial wall reactions during chronic transplant arteriopathy, but disorders of the lipoprotein metabolism--probably due to endothelial dysfunction--are also playing an important role like in atherosclerosis.