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Front Immunol. 2024 Apr 19;15:1399180. doi: 10.3389/fimmu.2024.1399180. eCollection 2024.

ABSTRACT

Primary humoral deficiency and secondary B-cell depletion may lead to prolonged Sars-Cov-2 infection due to a decreased viral clearance. Prolonged infection is mainly driven by the lack of anti-Sars-Cov-2 immunoglobulin (IVIg) especially in patients with no vaccine response. Anti-spike immunoglobulin can be provided by infusion of convalescent patients’ plasma: recent studies highlighted that commercial immunoglobulin show high titers of neutralizing IgG. We conducted a single center retrospective cohort. We included 9 patients (6 males, median age 74 years old): one patient with X-linked agammaglobulinemia and 8 patients treated with rituximab (2 granulomatosis with polyangiitis, 1 neuromyelitis optica, 4 low grade B-cell lymphoma and 1 EBV post-transplant lymphoproliferative disorder). Mean serum globulin was 4 ± 1.6 g/L. 7/8 had received at least 3 doses of mRNA anti-Sars-Cov-2 vaccine (median 4) with no response (anti-Spike IgG 0 for 6 patients). In this specific population requiring oxygen therapy but no intensive care support, the administration of IVIg was well tolerated and provided a swift improvement of clinical status, a significant decrease of inflammation associated to the an improvement of radiological patterns. Our results suggest that immunoglobulin could be used as a salvage therapy as an alternative to convalescent plasma but highly stringent patient selection is required due to the worldwide shortage of IVIg.

PMID:38707896 | PMC:PMC11069322 | DOI:10.3389/fimmu.2024.1399180

Cell. 2024 May 2:S0092-8674(24)00404-5. doi: 10.1016/j.cell.2024.04.009. Online ahead of print.

ABSTRACT

FMS-related tyrosine kinase 3 ligand (FLT3L), encoded by FLT3LG, is a hematopoietic factor essential for the development of natural killer (NK) cells, B cells, and dendritic cells (DCs) in mice. We describe three humans homozygous for a loss-of-function FLT3LG variant with a history of various recurrent infections, including severe cutaneous warts. The patients’ bone marrow (BM) was hypoplastic, with low levels of hematopoietic progenitors, particularly myeloid and B cell precursors. Counts of B cells, monocytes, and DCs were low in the patients’ blood, whereas the other blood subsets, including NK cells, were affected only moderately, if at all. The patients had normal counts of Langerhans cells (LCs) and dermal macrophages in the skin but lacked dermal DCs. Thus, FLT3L is required for B cell and DC development in mice and humans. However, unlike its murine counterpart, human FLT3L is required for the development of monocytes but not NK cells.

PMID:38701783 | DOI:10.1016/j.cell.2024.04.009

Front Immunol. 2024 Apr 18;15:1390022. doi: 10.3389/fimmu.2024.1390022. eCollection 2024.

ABSTRACT

PURPOSE: Previous studies have demonstrated that the majority of patients with an inborn error of immunity (IEI) develop a spike (S)-specific IgG antibody and T-cell response after two doses of the mRNA-1273 COVID-19 vaccine, but little is known about the response to a booster vaccination. We studied the immune responses 8 weeks after booster vaccination with mRNA-based COVID-19 vaccines in 171 IEI patients. Moreover, we evaluated the clinical outcomes in these patients one year after the start of the Dutch COVID-19 vaccination campaign.

METHODS: This study was embedded in a large prospective multicenter study investigating the immunogenicity of COVID-19 mRNA-based vaccines in IEI (VACOPID study). Blood samples were taken from 244 participants 8 weeks after booster vaccination. These participants included 171 IEI patients (X-linked agammaglobulinemia (XLA;N=11), combined immunodeficiency (CID;N=4), common variable immunodeficiency (CVID;N=45), isolated or undefined antibody deficiencies (N=108) and phagocyte defects (N=3)) and 73 controls. SARS-CoV-2-specific IgG titers, neutralizing antibodies, and T-cell responses were evaluated. One year after the start of the COVID-19 vaccination program, 334 study participants (239 IEI patients and 95 controls) completed a questionnaire to supplement their clinical data focusing on SARS-CoV-2 infections.

RESULTS: After booster vaccination, S-specific IgG titers increased in all COVID-19 naive IEI cohorts and controls, when compared to titers at 6 months after the priming regimen. The fold-increases did not differ between controls and IEI cohorts. SARS-CoV-2-specific T-cell responses also increased equally in all cohorts after booster vaccination compared to 6 months after the priming regimen. Most SARS-CoV-2 infections during the study period occurred in the period when the Omicron variant had become dominant. The clinical course of these infections was mild, although IEI patients experienced more frequent fever and dyspnea compared to controls and their symptoms persisted longer.

CONCLUSION: Our study demonstrates that mRNA-based booster vaccination induces robust recall of memory B-cell and T-cell responses in most IEI patients. One-year clinical follow-up demonstrated that SARS-CoV-2 infections in IEI patients were mild. Given our results, we support booster campaigns with newer variant-specific COVID-19 booster vaccines to IEI patients with milder phenotypes.

PMID:38698851 | PMC:PMC11063285 | DOI:10.3389/fimmu.2024.1390022

J Med Genet. 2024 May 2:jmg-2024-109853. doi: 10.1136/jmg-2024-109853. Online ahead of print.

ABSTRACT

BACKGROUND: Triokinase and FMN cyclase (TKFC) is a bifunctional enzyme involved in fructose metabolism. Triokinase catalyses the phosphorylation of fructose-derived glyceraldehyde (GA) and exogenous dihydroxyacetone (DHA), while FMN cyclase generates cyclic FMN. TKFC regulates the antiviral immune response by interacting with IFIH1 (MDA5). Previously reported pathogenic variants in TKFC are associated with either a multisystemic disease or isolated hypotrichosis with loose anagen hairs.

METHODS: Whole-exome sequencing identified a homozygous novel variant in TKFC (c.1624G>A; p.Gly542Arg) in an individual with a complex primary immunodeficiency disorder. The variant was characterised using enzymatic assays and yeast studies of mutant recombinant proteins.

RESULTS: The individual presented with chronic active Epstein-Barr virus disease and multiple bacterial and viral infections. Clinical investigations revealed hypogammaglobulinaemia, near absent natural killer cells and decreased memory B cells. Enzymatic assays showed that this variant displayed defective DHA and GA kinase activity while maintaining FMN cyclase activity. An allogenic bone marrow transplantation corrected the patient’s immunodeficiency.

CONCLUSION: Our report suggests that TKFC may have a role in the immunological system. The pathological features associated with this variant are possibly linked with DHA/GA kinase inactivation through a yet an unknown mechanism. This report thus adds a possible new pathway of immunometabolism to explore further.

PMID:38697782 | DOI:10.1136/jmg-2024-109853

Clin Immunol. 2024 Apr 30:110233. doi: 10.1016/j.clim.2024.110233. Online ahead of print.

ABSTRACT

Ataxia-telangiectasia (A-T) is a rare disorder caused by genetic defects of A-T mutated (ATM) kinase, a key regulator of stress response, and characterized by neurodegeneration, immunodeficiency, and high incidence of cancer. Here we investigated NK cells in a mouse model of A-T (Atm^-/-) showing that they are strongly impaired at killing tumor cells due to a block of early signaling events. On the other hand, in Atm^-/- littermates with thymic lymphoma NK cell cytotoxicity is enhanced as compared with ATM-proficient mice, possibly via tumor-produced TNF-α. Results also suggest that expansion of exhausted NKG2D⁺ NK cells in Atm^-/- mice is driven by low-level expression of stress-inducible NKG2D ligands, whereas development of thymoma expressing the high-affinity MULT1 ligand is associated with NKG2D down-regulation on NK cells. These results expand our understanding of immunodeficiency in A-T and encourage exploring NK cell biology in A-T patients in the attempt to identify cancer predictive biomarkers and novel therapeutic targets.

PMID:38697554 | DOI:10.1016/j.clim.2024.110233

BMC Pediatr. 2024 Apr 30;24(1):291. doi: 10.1186/s12887-024-04746-7.

ABSTRACT

BACKGROUND: X-linked agammaglobulinemia (XLA) is a primary immunodeficiency disease caused by mutations in the Bruton tyrosine kinase (BTK) gene. Individuals diagnosed with XLA are at an increased risk of developing autoimmune diseases. However, renal involvement are rare in cases of XLA.

CASE PRESENTATION: In this report, we discussed a specific case involving a 6-year-old boy with XLA who experienced recurrent upper respiratory tract infections since the age of one. He presented with symptoms of hematuria and proteinuria, and renal pathology confirmed the presence of immunoglobulin (Ig) A nephropathy. Treatment comprised glucocorticoids, mycophenolate mofetil, and intermittent intravenous immunoglobulin replacement therapy. Consequently, there was a remission of proteinuria and a partial improvement in hematuria.

CONCLUSIONS: In this study, we describe the first case of IgA nephropathy associated with XLA. This is an interesting phenotype found in XLA, and it provides valuable insights into the process of autoimmunity and the regulation of immune function in individuals with XLA. Based on our findings, we recommend the evaluation of immunoglobulin levels in patients diagnosed with IgA nephropathy.

PMID:38689221 | DOI:10.1186/s12887-024-04746-7

Nat Commun. 2024 Apr 30;15(1):3662. doi: 10.1038/s41467-024-47866-5.

ABSTRACT

Hematopoietic stem cell gene therapy (GT) using a γ-retroviral vector (γ-RV) is an effective treatment for Severe Combined Immunodeficiency due to Adenosine Deaminase deficiency. Here, we describe a case of GT-related T-cell acute lymphoblastic leukemia (T-ALL) that developed 4.7 years after treatment. The patient underwent chemotherapy and haploidentical transplantation and is currently in remission. Blast cells contain a single vector insertion activating the LIM-only protein 2 (LMO2) proto-oncogene, confirmed by physical interaction, and low Adenosine Deaminase (ADA) activity resulting from methylation of viral promoter. The insertion is detected years before T-ALL in multiple lineages, suggesting that further hits occurred in a thymic progenitor. Blast cells contain known and novel somatic mutations as well as germline mutations which may have contributed to transformation. Before T-ALL onset, the insertion profile is similar to those of other ADA-deficient patients. The limited incidence of vector-related adverse events in ADA-deficiency compared to other γ-RV GT trials could be explained by differences in transgenes, background disease and patient’s specific factors.

PMID:38688902 | DOI:10.1038/s41467-024-47866-5

Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2024 Apr;46(2):232-241. doi: 10.3881/j.issn.1000-503X.15556.

ABSTRACT

DNA is susceptible to various factors in vitro and in vivo and experience different forms of damage,among which double-strand break(DSB)is a deleterious form.To maintain the stability of genetic information,organisms have developed multiple mechanisms to repair DNA damage.Among these mechanisms,homologous recombination(HR)is praised for the high accuracy.The MRE11-RAD50-NBS1(MRN)complex plays an important role in HR and is conserved across different species.The knowledge on the MRN complex mainly came from the previous studies in Saccharomyces cerevisiae and Caenorhabditis elegans,while studies in the last decades have revealed the role of mammalian MRN complex in DNA repair of higher animals.In this review,we first introduces the MRN complex regarding the composition,structure,and roles in HR.In addition,we discuss the human diseases such as ataxia-telangiectasia-like disorder,Nijmegen breakage syndrome,and Nijmegen breakage syndrome-like disorder that are caused by dysfunctions in the MRN complex.Furthermore,we summarize the mouse models established to study the clinical phenotypes of the above diseases.

PMID:38686720 | DOI:10.3881/j.issn.1000-503X.15556

Medicina (B Aires). 2024;84(2):347-350.

ABSTRACT

Very early onset inflammatory bowel disease (VEOIBD) is a rare entity in pediatrics. Its association with primary immunodeficiencies of monogenic origin is known. We present the case of a patient diagnosed with VEOIBD who underwent massive paralleled exome sequencing. The result of the study showed a pathogenic variant in the RET proto-oncogene, associated with multiple endocrine neoplasia type 2A disease. There are no previous reports of association of RET proto-oncogene variants with VEOIBD. The presence of these two clinical entities cannot be attributed to a single genetic cause.

PMID:38683522

Rev Alerg Mex. 2024 Feb 1;71(1):80. doi: 10.29262/ram.v71i1.1378.

ABSTRACT

OBJECTIVE: Describe the design and implementation of a transdisciplinary care model for patients with hereditary angioedema in Colombia.

METHODS: Descriptive longitudinal observational study. 140 patients with hereditary angioedema were included in a transdisciplinary care model for one year. Seizure rates, hospitalizations, emergency room visits, quality of life, and pharmacological adherence were measured.

RESULTS: The model was associated with reductions of 76% in seizures, 66% in hospitalizations, and 87% in emergency room visits. Pharmacological adherence increased 19% and was complete after four months. The quality of life increased significantly.

CONCLUSIONS: Hereditary angioedema is an orphan disease that requires a comprehensive approach for effective care.

PMID:38683097 | DOI:10.29262/ram.v71i1.1378