Epitope-engineered human hematopoietic stem cells are shielded from CD123-targeted immunotherapy

Targeted eradication of transformed or otherwise dysregulated cells using monoclonal antibodies (mAb), antibody-drug conjugates (ADC), T cell engagers (TCE), or chimeric antigen receptor (CAR) cells is very effective for hematologic diseases. Unlike the breakthrough progress achieved for B cell malignancies, there is a pressing need to find suitable antigens for myeloid malignancies. CD123, the interleukin-3 (IL-3) receptor alpha-chain, is highly expressed in various hematological malignancies, including acute myeloid leukemia (AML). However, shared CD123 expression on healthy hematopoietic stem and progenitor cells (HSPCs) bears the risk for myelotoxicity. We demonstrate that epitope-engineered HSPCs were shielded from CD123-targeted immunotherapy but remained functional, while CD123-deficient HSPCs displayed a competitive disadvantage. Transplantation of genome-edited HSPCs could enable tumor-selective targeted immunotherapy while rebuilding a fully functional hematopoietic system. We envision that this approach is broadly applicable to other targets and cells, could render hitherto undruggable targets accessible to immunotherapy, and will allow continued posttransplant therapy, for instance, to treat minimal residual disease (MRD).

Dysregulated anti-oxidant signalling and compromised mitochondrial integrity negatively influence regulatory T cell function and viability in liver disease

BACKGROUND

Dysregulated inflammatory responses and oxidative stress are key pathogenic drivers of chronic inflammatory diseases such as liver cirrhosis (LC). Regulatory T cells (Tregs) are essential to prevent excessive immune activation and maintain tissue homeostasis. While inflammatory cues are well known to modulate the function and stability of Tregs, the extent to which Tregs are influenced by oxidative stress has not been fully explored.

METHODS

The phenotypic and functional properties of CD4+CD25+CD127lo/- Tregs isolated from patients with LC were compared to healthy controls (HC). Treg redox state was investigated by characterizing intracellular reactive oxygen species (ROS), NADPH oxidase-2 (Nox2) activity, mitochondrial function, morphology, and nuclear factor-erythroid 2-related factor (Nrf2) antioxidant signalling. The relevance of Nrf2 and its downstream target, Heme-oxygenase-1 (HO-1), in Treg function, stability, and survival, was further assessed using mouse models and CRISPR/Cas9-mediated HO-1 knock-out.

FINDINGS

Circulating Tregs from LC patients displayed a reduced suppressive function, correlating with liver disease severity, associated with phenotypic abnormalities and increased apoptosis. Mechanistically, this was linked to a dysregulated Nrf2 signalling with resultant lower levels of HO-1, enhanced Nox2 activation, and impaired mitochondrial respiration and integrity. The functional deficit in LC Tregs could be partially recapitulated by culturing control Tregs in patient sera.

INTERPRETATION

Our findings reveal that Tregs rely on functional redox homeostasis for their function, stability, and survival. Targeting Treg specific anti-oxidant pathways may have therapeutic potential to reverse the Treg impairment in conditions of oxidative damage such as advanced liver disease.

FUNDING

This study was funded by the Wellcome Trust (211113/A/18/Z).

Acute kidney injury in patients with COVID-19: a retrospective cohort study from Switzerland

BACKGROUND: Data about patients in Europe with corona virus disease-2019 (COVID-19) and acute kidney injury (AKI) are scarce. We examined characteristics, presentation and risk factors of AKI in patients hospitalised with COVID-19 in a tertiary hospital in Switzerland. METHODS: We reviewed health records of patients hospitalised with a positive nasopharyngeal polymerase chain reaction test for SARS-CoV2 between 1 February and 30 June 2020, at the University Hospital of Basel. The nadir creatinine of the hospitalisation was used as baseline. AKI was defined according the KDIGO guidelines as a 1.5× increase of baseline creatinine and in-hospital renal recovery as a discharge creatinine <1.25× baseline creatinine. Least absolute shrinkage and selection operator (LASSO) regression was performed to select predictive variables of AKI. Based on this a final model was chosen. RESULTS: Of 188 patients with COVID-19, 41 (22%) developed AKI, and 11 (6%) required renal replacement therapy. AKI developed after a median of 9 days (interquartile range [IQR] 5-12) after the first symptoms and a median of 1 day (IQR 0-5) after hospital admission. The peak AKI stages were stage 1 in 39%, stage 2 in 24% and stage 3 in 37%. A total of 29 (15%) patients were admitted to the intensive care unit and of these 23 (79%) developed AKI. In-hospital renal recovery at discharge was observed in 61% of all AKI episodes. In-hospital mortality was 27% in patients with AKI and 10% in patients without AKI. Age (adjusted odds ratio [aOR] 1.04, 95% confidence interval [CI] 1.01–1.08; p = 0.024), history of chronic kidney disease (aOR 3.47, 95% CI 1.16–10.49;p = 0.026), C-reactive protein levels (aOR 1.09, 95% CI 1.03–1.06; p = 0.002) and creatinine kinase (aOR 1.03, 95% CI 1.01–1.06; p = 0.002) were associated with development of AKI. CONCLUSIONS: AKI is common in hospitalised patients with COVID-19 and more often seen in patients with severe COVID-19 illness. AKI is associated with a high in-hospital mortality.

Venovenous extracorporeal membrane oxygenation to treat hypercapnia in a morbidly obese patient

Morbid obesity plays an increasingly important role in healthcare. Patients who are severely obese often suffer from a range of medical problems. One problem is obesity-related hypoventilation syndrome with its resulting hypercapnia. We report a case of a 33-year-old female patient who was in an extraordinarily bad medical state, with severe hypercapnia (pCO2 15.1 kPa), sepsis, acute anuric kidney failure and resulting acidosis (pH 6.96). Her body mass index was 84 kg/m2. Her chances of survival were considered very low after failed attempts at noninvasive ventilation. Based on prior research, we refrained from intubation and chose venovenous extracorporeal membrane oxygenation to treat the hypercapnia. In the entire medical literature, we are not aware of a similarly extraordinary case of obesity-related hypoventilation syndrome that could finally be treated successfully. The idea behind this case report is to consider venovenous extracorporeal membrane oxygenation as an alternative to intubation in this patient collective.

Venovenous extracorporeal membrane oxygenation to treat hypercapnia in a morbidly obese patient

Morbid obesity plays an increasingly important role in healthcare. Patients who are severely obese often suffer from a range of medical problems. One problem is obesity-related hypoventilation syndrome with its resulting hypercapnia. We report a case of a 33-year-old female patient who was in an extraordinarily bad medical state, with severe hypercapnia (pCO2 15.1 kPa), sepsis, acute anuric kidney failure and resulting acidosis (pH 6.96). Her body mass index was 84 kg/m2. Her chances of survival were considered very low after failed attempts at noninvasive ventilation. Based on prior research, we refrained from intubation and chose venovenous extracorporeal membrane oxygenation to treat the hypercapnia. In the entire medical literature, we are not aware of a similarly extraordinary case of obesity-related hypoventilation syndrome that could finally be treated successfully. The idea behind this case report is to consider venovenous extracorporeal membrane oxygenation as an alternative to intubation in this patient collective.

Non-Hodgkin's lymphoma in adolescents: experiences in 378 adolescent NHL patients treated according to pediatric NHL-BFM protocols

Age-related differences in the distribution, biology and treatment response of non-Hodgkin's lymphoma (NHL) in adolescents remain to be elucidated. The current analyses present clinical parameters and outcomes of adolescents treated in pediatric NHL-BFM trials. Patients were stratified by histological subtype: lymphoblastic lymphoma (LBL); mature B-NHL, including Burkitt's lymphoma/leukemia (BL/B-AL), diffuse B-cell lymphoma (DLBCL-CB) and mediastinal B-cell lymphoma (PMLBL); and anaplastic large cell lymphoma (ALCL). Between October 1986 and December 2007, 2915 patients were registered, including 378 (13%) adolescents (15-18 years) with BL/B-AL (n=101), ALCL (n=74), DLBCL-CB (n=55), T-LBL (n=45), PMLBL (n=24), pB-LBL (n=13) and rare or not-specified NHL subtypes (n=66). The 5-year event-free survival (EFS) was 79±2% for adolescents compared with 85±1% for patients aged <15 years (P=0.014). EFS was 83±7% for adolescents with T-LBL, 82±4% with BL/B-AL, 85±5% with DLBCL-CB, 57±10% with PMLBL and 70±6% with ALCL. According to sex, the 5-year EFS in females versus males, respectively, was 70±5 versus 83±2% overall (P=0.004), 57±17 versus 92±6% (P=0.0036) for T-LBL patients and 71±9 versus 97±3% (P=0.0067) for DLBCL-CB patients. Adolescents with NHL treated according to pediatric NHL-BFM protocols had an EFS of 79±2%, which is marginally inferior to that of children. In adolescents with T-LBL and DLBCL-CB, female sex was associated with a worse prognosis.

Capnovolumetry: a new tool for lung function testing in children with asthma

In capnovolumetry, the expiratory CO2 concentration of exhaled air is plotted against the volume and thereby allows to determine functional dead space volumes. This method might offer additional information in lung function testing in children and adolescents with bronchial asthma. We aimed at determining whether a bronchospasmolysis (BSL) effect in the lower airways could also be detected by capnovolumetry as reflected by changes in the functional threshold dead space volumes (VDT). In 47 patients (aged 4-16 years) with a mild persistent bronchial asthma, VDT were determined before and after bronchodilation prior to starting therapy with inhaled steroids and after 6 months of treatment. Additionally, spirometry and body plethysmography were performed in all patients. There were significantly higher VDT values after BSL before and after 6 months of therapy (P<0.0001). VDT values before BSL were tendatively higher after 6 months of therapy compared with baseline values (P=0.07). VDT values correlated with parameters derived from conventional pulmonary function testing, i.e. vital capacity, forced expiratory volume in 1 s (FEV1), and maximum expiratory flow (MEF50). As VDT values particularly reflect the volumes of the lower bronchi this method may provide supplementary information to conventional lung function tests which are based on breathing mechanics. This seems to be especially helpful in situations where body plethysmography is not available or cooperation in forced expiration manoeuvres is insufficient.

[A new breath actuated dry powder inhaler (Auto-Jethaler)]

BACKGROUND

The aim was to examine the handling of the recently developed breath actuated dry powder inhaler Auto-Jethaler (PulmoTec GmbH/Höchstädt, launch by Ratiopharm and CT Berlin).

METHOD

75 patients suffering from asthma, cystic fibrosis or primary ciliary dysfunction (age: 3 to 34 years; 29 female, 46 male) with mild or moderate bronchial obstruction took part in the study. Lung function testing including body plethysmography was performed to measure bronchial obstruction independent of effort. Peak Inspiratory Flow (PIF) was measured using a Fleisch pneumotachograph equipped with or without a Auto-Jethaler. Instead of the commercially available drug tablet a stainless steal ring device of equivalent resistance, easy to disinfect, was used. Actuation of the rotation mechanism which was triggered by inspiration at an inspiratory flow of about 40 L/min was accompanied by a rattling noise. Aims of the study were to examine, whether the subjects were able to handle the new device, and to measure PIF without and via Auto-Jethaler.

RESULTS

Handling of the Auto-Jethaler was found to be easy. All patients managed to reach or surpass the critical value of 40 L/min, even those with mild to moderate bronchial obstruction. PIF without Jethaler was 85 to 599 L/min, via Auto-Jethaler 40 to 215 L/min. PIF was significantly age dependent (p<0.001).

CONCLUSIONS

These findings suggest that the Auto-Jethaler will be an appropriate device for drug administration in children older than 3 years provided that they understand the inspiratory breathing manoeuvre.

Is transient tachypnoea of the newborn associated with polymorphisms in the epithelial sodium channel encoding gene? Investigation of the second transmembrane spanning domain of the alpha subunit

AIM

We hypothesized that polymorphisms in the region encoding for the second transmembrane spanning domain of the epithelial sodium channel may be one factor in the pathogenesis of transient tachypnoea of the newborn. We thus searched for polymorphisms in this region in neonates with transient tachypnoea of the newborn. We also investigated samples from preterm neonates with respiratory distress syndrome, as dysfunction of the epithelial sodium channel might also increase the risk for developing respiratory distress syndrome and influence its course.

METHODS

We used denaturing gradient gel electrophoresis to detect sequence variants in exon 12 and 13 of the epithelial sodium channel. Forty-three neonates with transient tachypnoea of the newborn (gestational age [mean +/- SD]: 38.3 +/- 1.2 completed weeks; birthweight: 3088 +/- 426 g), 57 neonates with RDS (gestational age: 29.6 +/- 3.5 completed weeks; birthweight: 1272 +/- 638 g), and 50 healthy controls were enrolled prospectively.

RESULTS

We did not detect any polymorphism. Neither did confirmative sequencing of this region in 16 neonates with transient tachypnoea of the newborn reveal any polymorphism.

CONCLUSION

We conclude that reasons other than polymorphisms in the second transmembrane spanning domain cause transient tachypnoea of the newborn.

Transient Tachypnea of the Newborn (TTN): A Role for Polymorphisms of Surfactant Protein B (SP-B) Encoding Gene?

BACKGROUND

Transient tachypnea of the newborn (TTN) is usually a benign self-limiting respiratory disorder in the immediate neonatal period. The lipophilic surfactant-associated protein B (SP-B) was demonstrated to be the most relevant structural component of the surfactant system for immediate postnatal pulmonary adaptation. We hypothesized genetic variations of surfactant protein B (heterozygous 121 ins 2 mutation er intron 4 polymorphisms) to be related to TTN.

PATIENTS AND METHOD

We screened genomic DNA of 83 healthy term neonates (gestational age: 39 (37 - 41) completed weeks [median and range]; birth weight: 3325 +/- 541 grams [mean +/- SD]) and 75 infants presenting with TTN (gestational age: 38 (37 - 41) completed wecks [median and range]; birth weight: 3091 +/- 435 grams [mean +/- SD]) by means of PCR-amplification, fragment length and sequence analysis. TTN was diagnosed an the basis of the clinical signs with respiratory rate > 60 breaths/minute, fraction of inspired oxygen > 0.21, and characteristic radiographic findings within less than 24 hours after birth. Newborns with any infection, pulmonary or cardiac congenital malformations, postnatal asphyxia and infants born to diabetic mothers were excluded.

RESULTS

In TTN-group the frequency of male infants (68.4 % versus 44.6 %, p < 0.05) and caeserian section were significantly higher (68.4 % versus 30.1 %, p < 0.05). We did not find any statistical difference in frequency of intron 4 variations between controls and TTN-group (8.4 % versus 10.7 %). None of the infants were heterozygous for the 121ins2 SP-B mutation.

CONCLUSIONS

WC conclude polymorphisms of intron 4 and heterozygous 121 ins 2 mutation not to associated with TTN.

[Cutaneous lesions and blood count changes in a 9-month old girl with glutaric aciduria type I]

Non-specific cutaneous lesions are common in patients suffering from acute myeloid leukemia (AML). Leukemic skin infiltrates are present in about 30% of cases of monoblastic or myelomonocytic leukemia. The appearance of specific skin lesions can precede bone marrow involvement. We report the case of a 9-month-old girl with acute myelogenous leukemia (FAB M5) and glutaric aciduria type I which initially presented with cutaneous lesions, anemia and leukopenia.

[Leishmaniasis with cutaneous and visceral involvement in a 13-month old boy]

Leishmaniasis is an anthropozoonosis caused by infection with leishmania parasites with either cutaneous, mucosal or visceral (kala-azar) involvement. While the benign cutaneous form is self-limited death occurs in approximately 80% of children with kala-azar when untreated. The diagnosis of kala-azar should not be missed in children presenting with fever, hepatosplenomegaly and pancytopenia especially with a history of sand fly bites. We report the case of a 13-month-old boy with both cutaneous and visceral involvement.

[Role of magnesium in cardiovascular pathology]

In the first part of the paper the Authors give an up-to-date analysis of our current knowledge of magnesium metabolism, its relation with other electrolytes (namely sodium, potassium, calcium) and clinical symptoms due to its deficiency. The Authors then focus their attention on the relations between magnesium and cardiovascular pathologies and underline the role which magnesium deficiency may play in the onset of various forms of coronary artery disease: preinfarction angina, myocardial infarction, threatening ventricular arrhythmia and sudden death.