Real World Management of Anaphylaxis Versus the National Institute for Health and Clinical Excellence (NICE) Guidelines.

Objectives  Anaphylaxis is an acute, life-threatening immediate allergic reaction caused by the sudden systemic release of mediators from mast cells. This study aims to assess the current practice of emergency management of children and adults diagnosed with anaphylaxis at the Royal Hospital, Muscat, Oman, in line with the National Institute for Health and Clinical Excellence (NICE) guidelines.  Methods This is an observational retrospective study of all anaphylaxis cases seen at the emergency department (ED) from January 2013 to January 2018 and compared with the management of anaphylaxis in the ED as per the NICE guidelines. Inclusion criteria were all patients, children (age 16 and below), and adults diagnosed with anaphylaxis based on the World Allergy Organization (WAO) criteria. Exclusion criteria are all cases labeled as anaphylaxis that did not match the WAO criteria for anaphylaxis. Results Of 100 patients with a preliminary diagnosis of anaphylaxis, 49 patients (49%) were true-anaphylaxis cases based on the WAO definition 16 were children (age 16 years and below), and 33 were adults ( age 16 years and above). The other 51 patients (51%) with misdiagnosed anaphylaxis were later diagnosed with spontaneous urticaria, septic shock, vocal cord dysfunction, severe asthma, and anxiety attack. All 49 patients with true-anaphylaxis appropriately received adrenaline intramuscularly at the ED. All 16 children were admitted, seen by an allergist, and received an adrenaline auto-injector when indicated. Only 5 of the 33 adults were admitted and seen by an allergist, and 4 of those required an adrenaline auto-injector upon discharge. The remaining 28 adults were discharged from the ED, and only 3 of these were referred to the allergist. None received an adrenaline auto-injector upon discharge from the ED, and no mention in the ED notes on patient education regarding allergen avoidance. Conclusion Third of the patients who presented to ED were children (<16 years), and two third were adults. Insect venom was the main reason for anaphylaxis in both age groups. There was an underutilization of adrenaline auto-injector prescriptions for adult patients. This could be very well improved by disseminating policies and guidelines to adult physicians.

Coexistence of sickle cell disease and systemic lupus erythematosus is associated with quantitative and qualitative impairments in circulating regulatory B cells.

The incidence of connective tissue diseases such as systemic lupus erythematous (SLE), in adult patients with sickle cell disease (SCD), appears to be increasing. The exact causes underlying this increased risk are still unknown, but a link with B regulatory (Breg) cells is possible as these cells suppress inflammatory responses, and maintain tolerance. Quantitative and qualitative analyses of circulating Breg cells were performed in a cohort of SCD patients with SLE, and their levels were correlated with key soluble mediators promoting autoreactive B cells. We demonstrated that levels of Breg cells were significantly decreased in SCD patients with SLE compared to patients with SCD only or healthy controls. Functional analysis of Breg cells from SCD patients with SLE revealed impairments in IL-10 production that correlated with lower levels of STAT3 phosphorylation, without abnormal expression of IL-10 receptor on Breg cells. On the other hand, BAFF levels were substantially elevated in SCD patients with SLE, but not significantly associated with Breg cell levels. Collectively, these results indicated numerical and functional deficits of Breg cells in SCD patients with SLE and their capacity to maintain tolerance and control inflammation is imbalanced, which leads to the development of autoimmune responses.

BCL10 loss-of-function novel mutation leading to atypical severe combined immunodeficiency.

BACKGROUND: Severe combined immunodeficiency (SCID) is characterized by severe, early-onset infection in infants. B-cell lymphoma/leukemia (BCL) 10 defects causing SCID have been reported previously in two patients. MATERIAL & METHODS: A seven-month-old female infant was admitted with bilateral pneumonia requiring ventilatory support. She had a history of recurrent infections starting from four months of age. The patient was investigated for primary immunodeficiency. RESULTS: Immunological investigations revealed hypogammaglobulinemia with normal CD4 and CD8 lymphocyte counts, while a lymphocyte proliferation assay showed absent response to phytohemagglutinin stimulation, thereby establishing the diagnosis of an atypical form of SCID. Genetic testing revealed a homozygous mutation in the BCL10 gene, with both parents demonstrating a heterozygous state (NM_003921.5:c.271A > C:p.[Thr91Pro]). The patient died before bone marrow transplantation due to severe disseminated adenovirus disease. CONCLUSION: We report the first patient from the Middle East with a novel homozygous mutation in the BCL10 gene causing SCID.

Loss of DIAPH1 causes SCBMS, combined immunodeficiency, and mitochondrial dysfunction.

BACKGROUND: Homozygous loss of DIAPH1 results in seizures, cortical blindness, and microcephaly syndrome (SCBMS). We studied 5 Finnish and 2 Omani patients with loss of DIAPH1 presenting with SCBMS, mitochondrial dysfunction, and immunodeficiency. OBJECTIVE: We sought to further characterize phenotypes and disease mechanisms associated with loss of DIAPH1. METHODS: Exome sequencing, genotyping and haplotype analysis, B- and T-cell phenotyping, in vitro lymphocyte stimulation assays, analyses of mitochondrial function, immunofluorescence staining for cytoskeletal proteins and mitochondria, and CRISPR-Cas9 DIAPH1 knockout in heathy donor PBMCs were used. RESULTS: Genetic analyses found all Finnish patients homozygous for a rare DIAPH1 splice-variant (NM_005219:c.684+1G>A) enriched in the Finnish population, and Omani patients homozygous for a previously described pathogenic DIAPH1 frameshift-variant (NM_005219:c.2769delT;p.F923fs). In addition to microcephaly, epilepsy, and cortical blindness characteristic to SCBMS, the patients presented with infection susceptibility due to defective lymphocyte maturation and 3 patients developed B-cell lymphoma. Patients' immunophenotype was characterized by poor lymphocyte activation and proliferation, defective B-cell maturation, and lack of naive T cells. CRISPR-Cas9 knockout of DIAPH1 in PBMCs from healthy donors replicated the T-cell activation defect. Patient-derived peripheral blood T cells exhibited impaired adhesion and inefficient microtubule-organizing center repositioning to the immunologic synapse. The clinical symptoms and laboratory tests also suggested mitochondrial dysfunction. Experiments with immortalized, patient-derived fibroblasts indicated that DIAPH1 affects the amount of complex IV of the mitochondrial respiratory chain. CONCLUSIONS: Our data demonstrate that individuals with SCBMS can have combined immune deficiency and implicate defective cytoskeletal organization and mitochondrial dysfunction in SCBMS pathogenesis.

Recurrent miscalling of missense variation from short-read genome sequence data.

BACKGROUND: Short-read resequencing of genomes produces abundant information of the genetic variation of individuals. Due to their numerous nature, these variants are rarely exhaustively validated. Furthermore, low levels of undetected variant miscalling will have a systematic and disproportionate impact on the interpretation of individual genome sequence information, especially should these also be carried through into in reference databases of genomic variation. RESULTS: We find that sequence variation from short-read sequence data is subject to recurrent-yet-intermittent miscalling that occurs in a sequence intrinsic manner and is very sensitive to sequence read length. The miscalls arise from difficulties aligning short reads to redundant genomic regions, where the rate of sequencing error approaches the sequence diversity between redundant regions. We find the resultant miscalled variants to be sensitive to small sequence variations between genomes, and thereby are often intrinsic to an individual, pedigree, strain or human ethnic group. In human exome sequences, we identify 2-300 recurrent false positive variants per individual, almost all of which are present in public databases of human genomic variation. From the exomes of non-reference strains of inbred mice, we identify 3-5000 recurrent false positive variants per mouse - the number of which increasing with greater distance between an individual mouse strain and the reference C57BL6 mouse genome. We show that recurrently miscalled variants may be reproduced for a given genome from repeated simulation rounds of read resampling, realignment and recalling. As such, it is possible to identify more than two-thirds of false positive variation from only ten rounds of simulation. CONCLUSION: Identification and removal of recurrent false positive variants from specific individual variant sets will improve overall data quality. Variant miscalls arising are highly sequence intrinsic and are often specific to an individual, pedigree or ethnicity. Further, read length is a strong determinant of whether given false variants will be called for any given genome - which has profound significance for cohort studies that pool datasets collected and sequenced at different points in time.