Genetics of severe congenital neutropenia as a gateway to personalized therapy

Exploring the landscape of congenital and idiopathic neutropenia in Moroccan children: a comprehensive retrospective analysis

Congenital neutropenia (CoN) is a heterogeneous group of inborn errors of immunity (IEI) characterized by recurrent infections and early onset of neutropenia (NP). This study aimed to investigate the demographic and clinical data of children with CoN and idiopathic neutropenia (IN) in Morocco. We performed a retrospective study of patients with CoN and analyzed the clinical and laboratory findings of patients with CoN and IN diagnosed between 1999 and 2018 in a clinical immunology unit of a large pediatric hospital. We identified 88 patients, 51 with IN and 37 with CoN. Fifty-seven percent were males, and 43% were females, ranging from 1 month to 19 years. The median age at onset was 8 months, and the median at diagnosis was 36 months. Consanguinity was observed in 57% of the cases, and a history of recurrent infections in the siblings was found in 27.3%. The most common infectious complications were ear, nose, and throat (ENT) infections, skin and soft tissue infections, and lung infections. Patients with CoN were classified into seven syndromes: 9 with severe congenital neutropenia, 11 with cyclic neutropenia, 6 with glycogen storage disease type 1b, 5 with poikiloderma with neutropenia, 3 with Griscelli syndrome, 2 with Hermansky-Pudlak syndrome type II, and 1 with Cohen syndrome. This study provides a comprehensive overview of CoN and IN in a pediatric cohort from Morocco, representing the country's most considerable single-center investigation of these conditions. Our findings highlight the significant burden of CoN, accounting for 5% of IEI in the Moroccan registry, a proportion higher than in some neighboring countries. The study emphasizes the early onset and severity of bacterial infections in CoN patients, underlining the critical need for timely and accurate diagnosis.

The CRISPR-Cas System and Clinical Applications of CRISPR-Based Gene Editing in Hematology with a Focus on Inherited Germline Predisposition to Hematologic Malignancies

Clustered regularly interspaced short palindromic repeats (CRISPR)-based gene editing has begun to transform the treatment landscape of genetic diseases. The history of the discovery of CRISPR/CRISPR-associated (Cas) proteins/single-guide RNA (sgRNA)-based gene editing since the first report of repetitive sequences of unknown significance in 1987 is fascinating, highly instructive, and inspiring for future advances in medicine. The recent approval of CRISPR-Cas9-based gene therapy to treat patients with severe sickle cell anemia and transfusion-dependent β-thalassemia has renewed hope for treating other hematologic diseases, including patients with a germline predisposition to hematologic malignancies, who would benefit greatly from the development of CRISPR-inspired gene therapies. The purpose of this paper is three-fold: first, a chronological description of the history of CRISPR-Cas9-sgRNA-based gene editing; second, a brief description of the current state of clinical research in hematologic diseases, including selected applications in treating hematologic diseases with CRISPR-based gene therapy, preceded by a brief description of the current tools being used in clinical genome editing; and third, a presentation of the current progress in gene therapies in inherited hematologic diseases and bone marrow failure syndromes, to hopefully stimulate efforts towards developing these therapies for patients with inherited bone marrow failure syndromes and other inherited conditions with a germline predisposition to hematologic malignancies.

Inborn errors of immunity: A field without frontiers

The study of primary immunodeficiencies or inborn errors of immunity continues to drive our knowledge of the function of the human immune system. From the outset, the study of inborn errors has focused on unraveling genetic etiologies and molecular mechanisms. Aided by the continuous growth in genetic diagnostics, the field has moved from the study of an infection dominated phenotype to embrace and unravel diverse manifestations of autoinflammation, autoimmunity, malignancy, and severe allergy in all medical disciplines. It has now moved from the study of ultrarare presentations to producing meaningful impact in conditions as diverse as inflammatory bowel disease, neurological conditions, and hematology. Beyond offering immunogenetic diagnosis, the study of underlying inborn errors of immunity in these conditions points to targeted treatment which can be lifesaving.

Hematological, biochemical, and histopathological evaluation of the Morus alba L. leaf extract from Brunei Darussalam: Acute toxicity study in ICR mice

Background

Studies have reported that the phytochemical content of Mulberry (Morus alba Linn.) is influenced by the area where it grows. On the other hand, the study of the bioactivity and toxicity of mulberry leaves from Brunei Darussalam still needs to be completed. In particular, the investigation regarding the safe dose for Mulberry's application from Brunei Darussalam has yet to be studied. Hence, toxicity information must be considered even though the community has used it for generations.

Aim

This study investigated Morus alba ethanolic leaf extract (MAE) to observe the acute toxicity in mice.

Methods

In particular, this study utilized 12 female Institute of Cancer Research mice, 8 weeks old, divided into 2 groups: the control group and the MAE group (2,000 mg/kg single dose). Physiology, hematology, biochemistry, and histology were analyzed during the study.

Results

The examination result indicated no mortality and behavioral changes throughout the testing period. However, the mice developed mild anemia and leukopenia, followed by decreased numbers of neutrophils, lymphocytes, and monocytes. In addition, the mice developed a mild hepatocellular injury, indicated by significant (p < 0.05) elevations of both alanine aminotransferase (ALT) and aspartate transaminase (AST). The histopathological findings of the liver were also consistent with the increment of ALT and AST, indicating mild hepatocellular necrosis through the eosinophilic cytoplasm and pyknosis (p > 0.05).

Conclusion

It was evident that a single oral administration of MAE was not lethal for mice (LD50, which was higher than 2,000 mg/kg). However, the administration of high doses of MAE must be carefully considered.

Reduced toxicity matched sibling bone marrow transplant results in excellent outcomes for severe congenital neutropenia

Severe congenital neutropenia (SCN) is caused by germline mutations, most commonly in ELANE, impacting neutrophil maturation and leading to high risk of life-threatening infections. Most patients with ELANE-mutant SCN can achieve safe neutrophil counts with chronic Granulocyte-Colony Stimulating Factor (G-CSF). However, up to 10% of patients have neutropenia refractory to G-CSF and require allogeneic stem cell transplant. Traditional conditioning for these patients includes busulfan and cyclophosphamide which is associated with significant toxicities. We present five patients with SCN without myeloid malignancy transplanted using a reduced toxicity regimen of busulfan, fludarabine and thymoglobulin. 5 pediatric patients with SCN underwent matched sibling donor bone marrow transplant (MSD-BMT) between 2014-2022 on or per CHP14BT057 (NCT02928991), a prospective, single center trial testing elimination of cyclophosphamide from conditioning in pediatric patients with single lineage inherited BMF syndromes. All patients had MSDs and no evidence of MDS. Conditioning consisted of PK-adjusted busulfan, fludarabine, and thymoglobulin, with calcineurin inhibitor and mycophenolate mofetil GVHD prophylaxis. With median follow-up of 48.4 months, overall and event-free survival were 100%. There was no acute GVHD and one instance of chronic limited GVHD. Patients exhibited >95% donor myeloid chimerism at 5 years post-BMT. Two patients experienced CMV reactivation without end-organ disease, and no other viral reactivation or significant infections occurred. MSD-BMT with reduced toxicity myeloablation for SCN provides excellent outcomes while minimizing toxicity. These data suggest that busulfan, fludarabine, and ATG can be considered an efficacious, low-toxicity standard of care regimen for patients with SCN undergoing MSD-BMT.

The paradox of autoimmunity and autoinflammation in inherited neutrophil disorders - in search of common patterns

Congenital defects of neutrophil number or function are associated with a severe infectious phenotype that may require intensive medical attention and interventions to be controlled. While the infectious complications in inherited neutrophil disorders are easily understood much less clear and explained are autoimmune and autoinflammatory phenomena. We survey the clinical burden of autoimmunity/autoinflammation in this setting, search for common patterns, discuss potential mechanisms and emerging treatments.