Clemens-Martin Wendtner

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening hyperinflammatory condition. While few diagnostic scores are established, none exist to predict both clinical course and time-point specific outcome of sHLH patients so far. We present a machine learning (ML)-based tool to predict Initial Disease Severity (IDS; defined as admission to intensive care units (ICU) OR death < 90 days without ICU admission) and mortality across different time points in sHLH patients. 167 adult sHLH patients from six study centers across three European countries were included retrospectively. Clinical and demographic features, course, survival, and laboratory data were assessed. Random forest models were trained with two sets of eight clinical and laboratory features: one to predict IDS, and five to predict mortality at distinct time points (30, 60, 90, 180 or 365 days). After calibration, the models were tested against hold-out test sets containing n = 32 (IDS) or n = 43 (mortality) sHLH patients. Overall, the models demonstrated strong discriminatory ability, overall performance, and accurate prediction of risk. Serum levels of the soluble interleukin-2 receptor (sIL-2R) and albumin (for IDS) or sIL-2R and platelet counts (for mortality prediction) showed the strongest contributions to the models' predictions. The HLH-Risk-Calculator is an exploratory tool predicting the clinical course of sHLH. External validation is critical to assess its validity, applicability, and robustness for real-world use. To this end, the calculator is available at www.hlh-risk-calculator.com for research use only, and is currently not intended for clinical decision-making.

The approval of ibrutinib over a decade ago introduced Bruton tyrosine kinase (BTK) inhibition as a foundational, chemotherapy-free treatment approach for chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL). A continuous single-agent BTK inhibitor (BTKi) or a time-limited B cell lymphoma 2 inhibitor (BCL2i)-based regimen plus an anti-CD20 monoclonal antibody or BTKi is now standard of care for CLL/SLL. Although ibrutinib offers durable remission for many patients, its use is limited by side effects associated with inhibition of kinases other than BTK (off-target effects). The second-generation BTKi zanubrutinib was developed to provide sustained BTK inhibition with greater selectivity for BTK in order to improve clinical efficacy and tolerability with minimized off-target effects. The head-to-head ALPINE study of patients with relapsed/refractory (R/R) CLL/SLL demonstrated superior efficacy with zanubrutinib versus ibrutinib, with superior overall response rates and prolonged progression-free survival (PFS), while acalabrutinib demonstrated non-inferior PFS outcomes versus ibrutinib in patients with high-risk R/R CLL/SLL. Data also showed improved safety outcomes with zanubrutinib versus ibrutinib with significantly lower rates of atrial fibrillation/flutter, and infection, and a trend toward lower rates of other adverse events associated with ibrutinib, with the exception of neutropenia. This is reflected in treatment guidelines for CLL, where zanubrutinib and the other approved second-generation BTKi, acalabrutinib, are recommended over ibrutinib owing to their superior safety profiles (particularly reduced cardiotoxicity). In this review, we consider the pharmacologic properties of zanubrutinib that differentiate it from ibrutinib and acalabrutinib, and provide a comprehensive overview of the efficacy and safety data that led to zanubrutinib monotherapy becoming a preferred therapy for a significant subgroup of patients with CLL/SLL. We also highlight trials in CLL/SLL and Richter's transformation with zanubrutinib in targeted therapy combinations that offer the potential for time-limited treatment courses.

The emergence of hitherto unknown viral pathogens presents a great challenge for researchers to develop effective therapeutics and vaccines within a short time to avoid an uncontrolled global spread, as seen during the coronavirus disease 2019 (COVID-19) pandemic. Therefore, rapid and simple methods to identify immunogenic antigens as potential therapeutical targets are urgently needed for a better pandemic preparedness. To address this problem, we chose the well-characterized Modified Vaccinia virus Ankara (MVA)-T7pol expression system to establish a workflow to identify immunogens when a new pathogen emerges, generate candidate vaccines, and test their immunogenicity in an animal model. By using this system, we detected severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) nucleoprotein (N)-, and spike (S)-specific antibodies in COVID-19 patient sera, which is in line with the current literature and our observations from previous immunogenicity studies. Furthermore, we detected antibodies directed against the SARS-CoV-2-membrane (M) and -ORF3a proteins in COVID-19 patient sera and aimed to generate recombinant MVA candidate vaccines expressing either the M or ORF3a protein. When testing our candidate vaccines in a prime-boost immunization regimen in humanized HLA-A2.1-/HLA-DR1-transgenic H-2 class I-/class II-knockout mice, we were able to demonstrate M- and ORF3a-specific cellular and humoral immune responses. Hence, the established workflow using the MVA-T7pol expression system represents a rapid and efficient tool to identify potential immunogenic antigens and provides a basis for future development of candidate vaccines.

Patients with chronic lymphocytic leukemia (CLL) treated with B-cell pathway inhibitors and anti-CD20 antibodies exhibit low humoral response rates following SARS-CoV-2 vaccination. To investigate this observation, a prospective single-institution study was conducted comparing peripheral blood mononuclear cell transcriptional response with antibody and T-cell response rates following heterologous BNT162b2/ChAdOx1 vaccination of 15 patients with CLL/small lymphocytic lymphoma (SLL). Two-dose antibody response rate was 40%, increasing to 53% after booster. Patients on Bruton tyrosine kinase inhibitor (BTKi) and venetoclax ± anti-CD20 antibody within 12 months of vaccination responded inferiorly compared with those under BTKi alone. The 2-dose–T-cell response rate was 80%, which increased to 93% after the booster dose. Key transcriptional findings were that interferon–mediated signaling activation including activation of the JAK-STAT pathway generally occurred within days of vaccination, but was independent from the magnitude of the antibody response. Increasing counts of IGHV genes were associated with B-cell reconstitution and improved humoral response rate in the vaccinated patients. T-cell responses in patients with CLL appeared independent of treatment status, whereas higher humoral response rate was associated with BTKi treatment and B-cell reconstitution. Boosting was particularly effective when intrinsic immune status was improved by CLL treatment. Limitations included studying a relatively small cohort, with different treatments and vaccination schedules.

Hemophagocytic lymphohistiocytosis (HLH) is a rare but often fatal hyperinflammatory syndrome caused by an inborn or acquired error of immunity. In adults, the underlying immunodeficiency generally arises alongside severe infections, malignancies, autoimmune diseases, and immunosuppressive treatment. To analyze risk factors and outcome in adults, we conducted a multicenter retrospective study. A total of 62 adult (age ≥18 years) patients met at least one of the following inclusion criteria: (1) ≥5 of 8 HLH-2004 criteria, (2) HScore ≥ 200 plus 4 HLH-2004 criteria, or (3) mutation compatible with an HLH diagnosis. Most patients (65%) were male, and the median age at diagnosis was 53.5 years (range, 19-81 years). All patients were assigned to 4 etiologic subgroups based on their most likely HLH trigger. The survival probability of the 4 etiologic subgroups differed significantly (P = .004, log-rank test), with patients with an underlying malignancy having the worst clinical outcome (1-year survival probability of 21%). The parameters older age, malignant trigger, elevated serum levels of aspartate transferase, creatinine, international normalized ratio, lactate dehydrogenase, sCD25, and a low albumin level and platelet count at treatment initiation were significantly (P < .1) associated with worse overall survival in the univariate Cox regression model. In multivariate analysis, sCD25 remained the only significant prognostic factor (P = .005). Our results suggest that sCD25 could be a useful marker for the prognosis of patients with HLH that might help to stratify therapeutic interventions.

Despite several potent targeted treatments for chronic lymphocytic leukemia (CLL), the clinical challenge of treating drug-resistant disease is emerging. In this study, we discovered that the dual-specific phosphatases DUSP1 and DUSP6 are required to negatively regulate Mitogen-activated protein kinases (MAPK) and thus counterbalance excessive MAPK activity to prevent apoptosis in CLL. We show that DUSP1 and DUSP6 are widely expressed in CLL and high expression of DUSP6 in CLL correlates with a poor clinical prognosis, which may reflect high levels of MAPK activity. Importantly, genetic deletion of the inhibitory phosphatase DUSP1 or DUSP6 and blocking DUSP1/6 function using a small molecule are toxic for CLL cells in vitro and in vivo. Analyzing downstream effects using global phospho-proteome approaches, we observed that acute activation of MAPK signaling by DUSP1/6 inhibition induces DNA damage response and thereby apoptotic cell death in CLL cells. This cell death is mediated by CHK kinases and can function independent of p53 and ATM, both effectors of DNA damage response, which are frequently deleted in CLL. Finally, we observed that DUSP1/6 inhibition is particularly effective against treatment-resistant CLL and therefore suggest transient DUSP1/6 inhibition as a promising novel treatment concept to eliminate drug-resistant CLL cells.

Patients with chronic lymphocytic leukemia (CLL) treated with B-cell pathway inhibitors and anti-CD20 antibodies exhibit low humoral response rate (RR) following SARS-CoV-2 vaccination. To investigate the relationship between the initial transcriptional response to vaccination with ensuing B and T cell immune responses, we performed a comprehensive immune transcriptome analysis flanked by antibody and T cell assays in peripheral blood prospectively collected from 15 CLL/SLL patients vaccinated with heterologous BNT162b2/ChAdOx1 with follow up at a single institution. The two-dose antibody RR was 40% increasing to 53% after booster. Patients on BTKi, venetoclax ± anti-CD20 antibody within 12 months of vaccination responded less well than those under BTKi alone. The two-dose T cell RR was 80% increasing to 93% after booster. Transcriptome studies revealed that seven patients showed interferon-mediated signaling activation within 2 days and one at 7 days after vaccination. Increasing counts of COVID-19 specific IGHV genes correlated with B-cell reconstitution and improved humoral RR. T cell responses in CLL patients appeared after vaccination regardless of treatment status. A higher humoral RR was associated with BTKi treatment and B-cell reconstitution. Boosting was particularly effective when intrinsic immune status was improved by CLL-treatment.

Background: Monkeypox is a zoonotic orthopoxvirus infection endemic in central and western Africa. In May 2022, human monkeypox infections including human-to-human transmission were reported in a multi-country outbreak in Europe and North America. Case presentations: Here we present the first two cases of monkeypox infection in humans diagnosed in Germany. We present clinical and virological findings, including the detection of monkeypox virus DNA in blood and semen. The clinical presentation and medical history of our patients suggest close physical contact during sexual interactions as the route of infection. Conclusion: Monkeypox requires rapid diagnosis and prompt public health response. The disease should be considered in the current situation especially the differential diagnosis of vesicular or pustular rash, particularly in patients with frequent sexual contacts. Most importantly, it is essential to raise awareness among all health professionals for the rapid and correct recognition and diagnosis of this disease, which is probably still underreported in Europe (Adler et al. in Lancet Infect Dis https://doi.org/10.1016/s1473-3099(22)00228-6, 2022).

In May 2022, human monkeypox infections including human-to-human transmission were reported in a multi-country outbreak in Europe and North America. With the first two German cases, we are providing clinical and virological findings, including the detection of monkeypox virus DNA in blood and semen. It is important to raise awareness among health professionals of the rapid and correct identification and diagnosis of this disease, which is probably still under-reported in Europe. We describe the first two cases of monkeypox (MPX) infections in Germany to highlight the importance of recent developments for health professionals worldwide and to share further observations related to human-to-human transmission in these cases. MPX is an orthopoxvirus infection that, with the exception of a few imported cases in the past, was previously thought to be endemic only in West and Central African countries [1, 2]. Beginning in 2018, the United Kingdom (UK) Health Security Agency has reported several imported cases associated with travellers from these countries [3]. One case reported on May 7, 2022, had a travel history to Nigeria. However, the two other cases within a family reported on May 13, 2022, neither had a travel history nor an epidemiological link to the previous case. On May 17, 2022, four additional UK cases were reported involving individuals who described themselves as belonging to the group of men who have sex with men (MSM). Subsequent testing for monkeypox virus (MPXV) in symptomatic MSM patients reporting to sexual health and sexually transmitted disease (STD) clinics in the UK and elsewhere revealed an increasing number of confirmed MPX cases in Europe [1].