Gene therapy and genome editing for primary immunodeficiency diseases

In past two decades the gene therapy using genetic modified autologous hematopoietic stem cells(HSCs)transduced with the viral vector has become a promising alternative option for treating primary immunodeficiency diseases(PIDs).Despite of some pitfalls at early stage clinical trials,the field of gene therapy has advanced significantly in the last decade with improvements in viral vector safety,preparatory regime for manufacturing high quality virus,automated CD34 cell purification.Hence,the overall outcome from the clinical trials for the different PIDs has been very encouraging.In addition to the viral vector based gene therapy,the recent fast moving forward developments in genome editing using engineered nucleases in HSCs has provided a new promising platform for the treatment of PIDs.This review provides an overall outcome and progress in gene therapy clinical trials for SCID-X,ADA-SCID,WAS,X-CGD,and the recent developments in genome editing technology applied in HSCs for developing potential therapy,particular in the key studies for PIDs.

An updated review on phenocopies of primary immunodeficiency diseases

Primary immunodeficiency diseases(PIDs)refer to a heterogenous group of disorders characterized clinically by increased susceptibility to infections,autoimmunity and increased risk of malignancies.These group of disorders present with clinical manifestations similar to PIDs with known genetic defects but have either no genetic defect or have a somatic mutation and thus have been labelled as“Phenocopies of PIDs”.These diseases have been further subdivided into those associated with somatic mutations and those associated with presence of auto-antibodies against various cytokines.In this review,we provide an update on clinical manifestations,diagnosis and management of these diseases.

Current status and prospects of primary immunodeficiency diseases in Asia

Primary Immunodeficiency Diseases(PIDs)are increasingly being reported across the World.Several advances have been made in the diagnostic and therapeutic research related to PIDs.With increasing awareness,the field of PIDs has rapidly evolved in Asia as well.In this review,we summarize the progress that has been made in the field of PIDs in Asian countries;major limitations and challenges faced by the clinicians working in this field in Asia;difference in spectrum of PIDs in Asia from rest of the World;current state of diagnostic and treatment facilities available in various countries in Asia and the future prospects of these diseases in the continent.

Druggable monogenic immune defects hidden in diverse medical specialties:Focus on overlap syndromes

In the last two decades two new paradigms changed our way of perceiving primary immunodeficiencies:An increasing number of immune defects are more associated with inflammatory or autoimmune features rather than with infections.Some primary immune defects are due to hyperactive pathways that can be targeted by specific inhibitors,providing innovative precision treatments that can change the natural history of diseases.In this article we review some of these“druggable”inborn errors of immunity and describe how they can be suspected and diagnosed in diverse pediatric and adult medicine specialties.Since the availability of precision treatments can dramatically impact the course of these diseases,preventing the development of organ damage,it is crucial to widen the awareness of these conditions and to provide practical hints for a prompt detection and cure.

Oral granuloma in a pediatric patient with chronic graft-versus-host disease:A case report

BACKGROUND Oral mucositis is often observed with graft-versus-host disease(GVHD);however,the occurrence of oral granuloma is rare.The rapid increase in granulomatous lesions should be distinguished from malignant tumors in patients with GVHD because malignant diseases can develop in those patients.This case is the youngest pediatric patient with granuloma associated with GVHD.CASE SUMMARY The patient was a 1-year and 5-mo-old girl who presented to our department for the management of oral nodules.At the age of 5 mo,she was diagnosed with primary immunodeficiency disease,cord blood transplant was performed at 11 mo and bone marrow transplant at 1 year of age.After transplantation,GVHD and oral mucositis developed,and tacrolimus was administered.Interestingly,nodules appeared on the lower lip and buccal mucosa,which spontaneously disappeared.Then,a new nodule appeared on the left lateral border of the tongue.Resection was performed and the histopathological diagnosis was granuloma.The origin of these nodules were considered to be the fibroblasts activated under inflammation caused by GVHD because the calcineurin inhibitor tacrolimus acted on their proliferation.CONCLUSION It is very important to distinguish oral granulomatous lesions from malignancies if GVHD is present at the base and if immunosuppressive agents and steroids are being administered.

Recent advances in lentiviral vectors for gene therapy

Lentiviral vectors(LVs), derived from human immunodeficiency virus, are powerful tools for modifying the genes of eukaryotic cells such as hematopoietic stem cells and neural cells. With the extensive and in-depth studies on this gene therapy vehicle over the past two decades, LVs have been widely used in both research and clinical trials. For instance, third-generation and selfinactive LVs have been used to introduce a gene with therapeutic potential into the host genome and achieve targeted delivery into specific tissue. When LVs are employed in leukemia, the transduced T cells recognize and kill the tumor B cells;in β-thalassemia, the transduced CD34^(+) cells express normal β-globin;in adenosine deaminase-deficient severe combined immunodeficiency, the autologous CD34^(+) cells express adenosine deaminase and realize immune reconstitution. Overall, LVs can perform significant roles in the treatment of primary immunodeficiency diseases, hemoglobinopathies, B cell leukemia, and neurodegenerative diseases. In this review, we discuss the recent developments and therapeutic applications of LVs. The safe and efficient LVs show great promise as a tool for human gene therapy.

A novel point mutation in CD18 causing leukocyte adhesion deficiency in a Chinese patient

Background Leukocyte adhesion deficiency type 1 （LAD-l） is a rare, autosomal recessive inherited immunodeficiency disease characterized by recurrent severe bacterial infection, impaired pus formation, poor wound healing, associated with the mutation in the CD18 gene responsible for the ability of the leucocytes to migrate from the blood stream towards the site of inflammation. Correct and early diagnosis of LAD-1 is vital to the success of treatment and prevention of aggressive infections. The purpose of this study was to collect the clinical findings of the disease and to identify the genetic entity. Methods CD18 expression in the peripheral blood leukocytes from the patient, his parents and normal control was measured with flow cytometry. The entire coding regions of the CD18 gene were screened with direct sequencing genomic DNA. Results CD18 expression level on this patient＇s leukocyte surface was significantly decreased, with normal level in control group, his father and mother. Gene analysis revealed that this patient had a homozygous c.899A〉T missense mutation in exon 8 of CD18 gene, causing the substitution of Asp to Val at the 300 amino acid. His parents were both heterozygous carriers while no such mutation was found in 50 normal controls. Conclusion This study disclosed a novel point mutation Asp 300 Val located in a highly conserved region （HCR） of CD18 and confirmed the heterogeneity of the mutations causing LAD-1, indicating it was quite beneficial to establish correct and early diagnosis in children with severe LAD-1.