Enrichment of Immune Dysregulation Disorders in Adult Patients with Human Inborn Errors of Immunity

Human inborn errors of immunity (IEI) comprise a group of diseases resulting from molecular variants that compromise innate and adaptive immunity. Clinical features of IEI patients are dominated by susceptibility to a spectrum of infectious diseases, as well as autoimmune, autoinflammatory, allergic, and malignant phenotypes that usually appear in childhood, which is when the diagnosis is typically made. However, some IEI patients are identified in adulthood due to symptomatic delay of the disease or other reasons that prevent the request for a molecular study. The application of next-generation sequencing (NGS) as a diagnostic technique has given rise to an ever-increasing identification of IEI-monogenic causes, thus improving the diagnostic yield and facilitating the possibility of personalized treatment. This work was a retrospective study of 173 adults with IEI suspicion that were sequenced between 2005 and 2023. Sanger, targeted gene-panel, and whole exome sequencing were used for molecular diagnosis. Disease-causing variants were identified in 44 of 173 (25.43%) patients. The clinical phenotype of these 44 patients was mostly related to infection susceptibility (63.64%). An enrichment of immune dysregulation diseases was found when cohorts with molecular diagnosis were compared to those without. Immune dysregulation disorders, group 4 from the International Union of Immunological Societies Expert Committee (IUIS), were the most prevalent among these adult patients. Immune dysregulation as a new item in the Jeffrey Model Foundation warning signs for adults significantly increases the sensitivity for the identification of patients with an IEI-producing molecular defect.

We refuse to die - T cells causing havoc

This issue of the Biomedical Journal offers insights into the origin and consequences of different lymphoproliferative disorders and autoimmunity. Furthermore we learn about RASopathies, a group of congenital disorders that occur rather frequently. Then the current ELISA assays for measuring antibody avidity are critically examined, the relationship between female sex steroid hormones and cardiovascular disease is explored, and an assessment of persistent diarrhea as a leading cause of child death in India is performed. Additionally, there are several articles about COVID-19, presenting its connection to neutrophil recruitment and acute respiratory distress syndrome, as well as its relation to changes in the vascular glycocalyx. A COVID-19 case study from the emergency room is presented. We are also introduced to novel treatment approaches against COVID-19 like the construction of peptide-based vaccines, or targeting the respiratory tract microbiome. Finally, there is an assessment about how prepared medical students at a Taiwan University feel for independent practice, and another article about the treatment of intravascular large B cell lymphoma in a Taiwanese institution. Lastly, we discover possible surgery techniques in the case of external auditory canal osteoma.

Role of γ-Secretase Inhibitors for the Treatment of Diverse Disease Conditions through Inhibition of Notch Signaling Pathway

γ-Secretase is an intramembrane protease sub-assembly which that sunders transmembrane proteins. They are involved in intramembrane proteolysis and also contribute to the regeneration of transmembrane protein. The amyloid precursor protein (APP) is a typical γ-secretase substrate. These proteins are cleaved to produce 36-43 amyloid-beta (Aβ) amino acid peptides. Abnormal folding of these protein fragments leads to amyloid plaques; , frequently encountered in Alzheimer's disease. Some Type I class of integral membrane proteins are processed under the influence of γ-secretase, such as receptor tyrosine-protein kinase erbB4 and CD44 glycoprotein. γ-Secretase is being explored in a number of diseases as a clinical goal. Both γ-secretase inhibitors (GSIs) and γ-secretase modulators (GSMs) are being evaluated for this purpose. A large amount of γ-secretase inhibitors (GSIs) from peptide to non-peptide have been disclosed, offering several lead compounds for the design and optimization of γ-secretase targets, but most GSIs lacks sufficient potency, low penetration in the brain, and low selectiveness. γ-Secretase inhibitors are obliquely a regulator of a γ-secretase substrate Notch, and valuable in the understanding of the development of β-amyloid peptide (Aβ). These γ-secretase inhibitors block the Notch signaling pathway in autoimmune and lymphoproliferative disorders like autoimmune lymphoproliferative syndrome (ALPS) and systemic lupus erythematosus (SLE), and perhaps even in cancerous cell proliferation, angiogenesis, and cellular differentiation of human-induced pluripotent stem cells (hiPSC). The current review portrays the mechanism, regulation, and inhibition of γ-secretase in the management of a wide assortment of diseases.

Flow Cytometry Assays in Primary Immunodeficiency Diseases

Inborn errors of immunity are the cause of the primary immunodeficiency diseases, an extremely diverse group of genetic defects that are inherited in Mendelian fashion and result in the impairment of development and/or function of key components of the immune system. Since the last publication of this chapter in 2011, there have been approximately 100 new primary immunodeficiency diseases officially classified by the "Expert Committee for Primary Immunodeficiency" who met in 2015 and the numbers will continue to rise with the continued evolution and widespread adoption of genomic technologies. The ultimate diagnostic modality involves the identification of a mutation in a gene whose product is known to be involved in immunity. DNA sequencing is however still a rather time-consuming technology. Flow cytometry applications have evolved that are rapid, specific, and relatively inexpensive to screen for abnormalities associated with primary immunodeficiency diseases. The numerous flow cytometry procedures that have been developed to detect abnormalities in peripheral blood cells of primary immunodeficiency patients can barely be covered in an entire book, let alone one chapter. Instead of attempting to cover each disease with a specific assay or test, we will review four procedures each covering one of the three following broad forms of immune abnormalities observed in primary immunodeficiency, i.e., immune subset abnormalities, immune marker abnormalities, and immune function abnormalities.

A case report of septic shock syndrome caused by S. pneumoniae in an immunocompromised patient despite of vaccination

Background and case presentation

We report a case of septic shock syndrome caused by Streptococcus pneumoniae in a patient who had undergone splenectomy due to an autoimmune lymphoproliferative syndrome (ALPS), which is characterized as a dysfunction of immunoregulation. Although the patient was vaccinated with a conjugated polysaccharide vaccine after the splenectomy, he was still susceptible to S. pneumoniae infection, because the isolated serovar (24F), a serovar long thought to be apathogenic, is not covered by any vaccine currently approved, neither a conjugated nor an unconjugated polysaccharide one.

Conclusions

This case demonstrates that, due to presence of different serovars, also infections with bacteria against which patients are vaccinated have to be considered as differential diagnosis. Although vaccine development has extended the coverage of S. pneumoniae from 7 to 23 serovars within recent years, there is still demand for novel vaccines which can provide broader protection also against so-thought “apathogenic” strains, especially for groups at high risk.

An atypical case of late-onset systemic lupus erythematosus with systemic lymphadenopathy and severe autoimmune thrombocytopenia/neutropenia mimicking malignant lymphoma

Here, we report a rare case of systemic lupus erythematosus (SLE) with conspicuous manifestation of hematological abnormalities. At onset, the 52-year-old male patient showed systemic lymphadenopathy and splenomegaly, severe autoimmune thrombocytopenia, and autoimmune neutropenia. Bone marrow examination and lymph node biopsy excluded the possibility of malignant lymphoma. Based on laboratory findings, he was finally diagnosed with combined autoimmune cytopenia coupled with SLE. Atypical clinical manifestations of SLE prompted us to explore the possibility of autoimmune lymphoproliferative syndrome (ALPS). However, we did not detect an increased number of CD4^-/CD8^-, CD3⁺, TCRαβ⁺ double-negative T cells in the circulating blood or dysfunctional T cell apoptosis in the Fas/Fas ligand pathway due to mutations in the FAS, FASLG or CASP10 genes. Combined autoimmune cytopenia is a rare clinical entity that in some cases co-occurs with other autoimmune diseases. Given that most SLE patients presenting atypical hematological manifestations at an early stage subsequently exhibit typical systemic manifestations, the present case raises the possibility that initial hematological abnormalities may be signs of unexpected SLE manifestations.