SAMD9L autoinflammatory or ataxia pancytopenia disease mutations activate cell-autonomous translational repression.

Sterile α motif domain-containing protein 9-like (SAMD9L) is encoded by a hallmark interferon-induced gene with a role in controlling virus replication that is not well understood. Here, we analyze SAMD9L function from the perspective of human mutations causing neonatal-onset severe autoinflammatory disease. Whole-genome sequencing of two children with leukocytoclastic panniculitis, basal ganglia calcifications, raised blood inflammatory markers, neutrophilia, anemia, thrombocytopaenia, and almost no B cells revealed heterozygous de novo SAMD9L mutations, p.Asn885Thrfs*6 and p.Lys878Serfs*13. These frameshift mutations truncate the SAMD9L protein within a domain a region of homology to the nucleotide-binding and oligomerization domain (NOD) of APAF1, ∼80 amino acids C-terminal to the Walker B motif. Single-cell analysis of human cells expressing green fluorescent protein (GFP)-SAMD9L fusion proteins revealed that enforced expression of wild-type SAMD9L repressed translation of red fluorescent protein messenger RNA and globally repressed endogenous protein translation, cell autonomously and in proportion to the level of GFP-SAMD9L in each cell. The children's truncating mutations dramatically exaggerated translational repression even at low levels of GFP-SAMD9L per cell, as did a missense Arg986Cys mutation reported recurrently as causing ataxia pancytopenia syndrome. Autoinflammatory disease associated with SAMD9L truncating mutations appears to result from an interferon-induced translational repressor whose activity goes unchecked by the loss of C-terminal domains that may normally sense virus infection.

Intrinsic Defects in B Cell Development and Differentiation, T Cell Exhaustion and Altered Unconventional T Cell Generation Characterize Human Adenosine Deaminase Type 2 Deficiency.

PURPOSE: Deficiency of adenosine deaminase type 2 (ADA2) (DADA2) is a rare inborn error of immunity caused by deleterious biallelic mutations in ADA2. Clinical manifestations are diverse, ranging from severe vasculopathy with lacunar strokes to immunodeficiency with viral infections, hypogammaglobulinemia and bone marrow failure. Limited data are available on the phenotype and function of leukocytes from DADA2 patients. The aim of this study was to perform in-depth immunophenotyping and functional analysis of the impact of DADA2 on human lymphocytes. METHODS: In-depth immunophenotyping and functional analyses were performed on ten patients with confirmed DADA2 and compared to heterozygous carriers of pathogenic ADA2 mutations and normal healthy controls. RESULTS: The median age of the patients was 10 years (mean 20.7 years, range 1-44 years). Four out of ten patients were on treatment with steroids and/or etanercept or other immunosuppressives. We confirmed a defect in terminal B cell differentiation in DADA2 and reveal a block in B cell development in the bone marrow at the pro-B to pre-B cell stage. We also show impaired differentiation of CD4+ and CD8+ memory T cells, accelerated exhaustion/senescence, and impaired survival and granzyme production by ADA2 deficient CD8+ T cells. Unconventional T cells (i.e. iNKT, MAIT, Vδ2+ γδT) were diminished whereas pro-inflammatory monocytes and CD56bright immature NK cells were increased. Expression of the IFN-induced lectin SIGLEC1 was increased on all monocyte subsets in DADA2 patients compared to healthy donors. Interestingly, the phenotype and function of lymphocytes from healthy heterozygous carriers were often intermediate to that of healthy donors and ADA2-deficient patients. CONCLUSION: Extended immunophenotyping in DADA2 patients shows a complex immunophenotype. Our findings provide insight into the cellular mechanisms underlying some of the complex and heterogenous clinical features of DADA2. More research is needed to design targeted therapy to prevent viral infections in these patients with excessive inflammation as the overarching phenotype.

Intraocular solitary extramedullary plasmacytoma presenting as unilateral anterior and intermediate uveitis preceded by refractory glaucoma.

BACKGROUND: Solitary extramedullary plasmacytoma (SEP) is a localised proliferation of monoclonal plasma cells involving soft tissue with no or minimal bone marrow involvement and no other systemic evidence of multiple myeloma. Intraocular involvement is exceedingly rare. CASE PRESENTATION: We report a 78-year-old man who was referred with glaucoma in the right eye. He subsequently developed anterior chamber (AC) inflammation and refractory glaucoma then dense vitritis. A vitrectomy was performed with the biopsy revealing numerous plasma cells with atypical findings. In conjunction with the flow cytometry results, and a systemic work up excluding multiple myeloma, a diagnosis of SEP was made. The patient was treated with ocular external beam radiotherapy with resolution of the intraocular inflammation and control of the intraocular pressure. He remains well with no local recurrence and no development of multiple myeloma over a follow up period of 2.5 years. CONCLUSIONS: This is the first case report of SEP presenting as intraocular inflammation without a uveal tract mass.

Nasal mucosal brushing as a diagnostic method for allergic rhinitis.

Background: Allergen specific immunoglobulin E (spIgE) in the nasal mucosa is a biomarker for local allergic rhinitis. Inferior turbinate tissue biopsy is a sensitive method to detect nasal spIgE but is invasive. Nasal brushing is a relatively noninvasive method to detect nasal spIgE that may be of comparable diagnostic utility. Objective: To assess the performance of nasal brushing to obtain a nasal spIgE sample compared with an inferior turbinate tissue biopsy among patients who underwent turbinate surgery. Methods: A diagnostic cross-sectional study that involved participants who were undergoing turbinate surgery was performed. Nasal brushing, inferior turbinate tissue biopsy, blood collection, and skin-prick test (SPT) were performed perioperatively and tested for house-dust allergens. A receiver operating curve was used to assess the performance of the nasal brushings to obtain nasal spIgE samples compared with the inferior turbinate tissue biopsy. The diagnostic utility of nasal brushings of spIgE compared with serum spIgE testing and SPT was also assessed. Results: A total of 157 patients (41.61 ± 14.83 years; 37.6% women) were included. Nasal brushing was an excellent method to sample for nasal spIgE compared with inferior turbinate tissue biopsy (Area under curve (AUC) 0.87 [95% confidence interval {CI}, 0.81-0.93], p < 0.01). Positive house-dust allergen spIgE results of nasal brushings was defined as > 0.1 kUA/L. Nasal brushings for spIgE sampling was also able to predict the presence of serum spIgE (AUC 0.93 [95% CI, 0.89-0.97], p < 0.01) and SPT (AUC 0.80 [95% CI, 0.72-0.87], p < 0.01). Conclusion: Nasal brushing constituted an easy and relatively noninvasive method to sample nasal epithelium. This sampling technique was comparable with an inferior turbinate tissue biopsy and may be developed as a diagnostic tool for the diagnosis of local allergic rhinitis.

Factors determining whether diffuse large B-cell lymphoma samples are detected by flow cytometry.

INTRODUCTION: Flow cytometry (FCM) is widely used in the diagnosis of mature B-cell neoplasms (MBN), and FCM data are usually consistent with morphological findings. However, diffuse large B-cell lymphoma (DLBCL), a common MBN, is sometimes not detected by FCM. This study aimed to explore factors that increase the likelihood of failure to detect DLBCL by FCM. METHODS: Cases with a final diagnosis of DLBCL that were analysed by eight-colour FCM were retrospectively collated. Clinical, FCM, histopathological and genetic data were compared between cases detected and cases not detected by FCM. RESULTS: DLBCL cases from 135 different patients were analysed, of which 22 (16%) were not detected by FCM. In samples not detected by flow cytometry, lymphocytes were a lower percentage of total events (p = 0.02), and T cells were a higher percentage of total lymphocytes (p = 0.01). Cases with high MYC protein expression on immunohistochemistry were less likely to be missed by FCM (p = 0.011). Detection of DLBCL was not different between germinal centre B-cell (GCB) and non-GCB subtypes, not significantly affected by the presence of necrosis or fibrosis, and not significantly different between biopsy specimens compared to fine-needle aspirates, or between samples from nodal compared to extranodal tissue. CONCLUSION: The study identifies several factors which affect the likelihood of DLBCL being missed by FCM. Even with eight-colour analysis, FCM fails to detect numerous cases of DLBCL.

Human PIK3R1 mutations disrupt lymphocyte differentiation to cause activated PI3Kδ syndrome 2.

Heterozygous loss-of-function (LOF) mutations in PIK3R1 (encoding phosphatidylinositol 3-kinase [PI3K] regulatory subunits) cause activated PI3Kδ syndrome 2 (APDS2), which has a similar clinical profile to APDS1, caused by heterozygous gain-of-function (GOF) mutations in PIK3CD (encoding the PI3K p110δ catalytic subunit). While several studies have established how PIK3CD GOF leads to immune dysregulation, less is known about how PIK3R1 LOF mutations alter cellular function. By studying a novel CRISPR/Cas9 mouse model and patients' immune cells, we determined how PIK3R1 LOF alters cellular function. We observed some overlap in cellular defects in APDS1 and APDS2, including decreased intrinsic B cell class switching and defective Tfh cell function. However, we also identified unique APDS2 phenotypes including defective expansion and affinity maturation of Pik3r1 LOF B cells following immunization, and decreased survival of Pik3r1 LOF pups. Further, we observed clear differences in the way Pik3r1 LOF and Pik3cd GOF altered signaling. Together these results demonstrate crucial differences between these two genetic etiologies.

Divergent human populations show extensive shared IGK rearrangements in peripheral blood B cells.

We have analysed the transcribed immunoglobulin kappa (IGK) repertoire of peripheral blood B cells from four individuals from two genetically distinct populations, Papua New Guinean and Australian, using high-throughput DNA sequencing. The depth of sequencing data for each individual averaged 5,548 high-quality IGK reads, and permitted genotyping of the inferred IGKV and IGKJ germline gene segments for each individual. All individuals were homozygous at each IGKJ locus and had highly similar inferred IGKV genotypes. Preferential gene usage was seen at both the IGKV and IGKJ loci, but only IGKV segment usage varied significantly between individuals. Despite the differences in IGKV gene utilisation, the rearranged IGK repertoires showed extensive identity at the amino acid level. Public rearrangements (those shared by two or more individuals) made up 60.2% of the total sequenced IGK rearrangements. The total diversity of IGK rearrangements of each individual was estimated to range from just 340 to 549 unique amino acid sequences. Thus, the repertoire of unique expressed IGK rearrangements is dramatically less than previous theoretical estimates of IGK diversity, and the majority of expressed IGK rearrangements are likely to be extensively shared in individual human beings.

Protection against Nippostrongylus brasiliensis infection in mice is independent of GM-CSF.

Granulocyte macrophage-colony stimulating factor (GM-CSF) is a cytokine with the capacity to promote inflammation in a wide variety of infectious and inflammatory diseases. These conditions include allergic airway inflammation, which is driven by T-helper 2 (Th2) cells. Because of the importance of Th2 cells in parasite infections, we have investigated the role of GM-CSF in mice infected with the nematode Nippostrongylus brasiliensis. The effect of primary and secondary infection was investigated in mice lacking functional genes for GM-CSF (CSF2 genes) (ΔGM-CSF mice), and in mice lacking the cytokine receptor common ß chain (Δß mice), the latter being unable to signal in response to GM-CSF and interleukin (IL)-5. ΔGM-CSF mice showed no significant defect in parasite immunity, measured by larval numbers in the lungs, worm numbers in the intestine or egg numbers in the faeces, in either primary or secondary infection. By contrast, the Δß mice showed increased parasite burden, with higher numbers of lung larvae after secondary infection and higher numbers of intestinal worms and faecal eggs after both primary and secondary infection. Unexpectedly, there were increased numbers of circulating eosinophils in the ΔGM-CSF mice, associated with significantly reduced larval numbers in the lungs. These results indicate that GM-CSF is redundant in protection against N. brasiliensis infection, and that the increased susceptibility of Δß mice to infection is likely to be attributed to the lack of IL-5 signalling in these mice. The results suggest that clinical use of agents that neutralise GM-CSF may not be associated with increased risk of parasite infection.

Bench-to-bedside review: Immunoglobulin therapy for sepsis - biological plausibility from a critical care perspective.

Sepsis represents a dysregulated host response to infection, the extent of which determines the severity of organ dysfunction and subsequent outcome. All trialled immunomodulatory strategies to date have resulted in either outright failure or inconsistent degrees of success. Intravenous immunoglobulin (IVIg) therapy falls into the latter category with opinion still divided as to its utility. This article provides a narrative review of the biological rationale for using IVIg in sepsis. A literature search was conducted using the PubMed database (1966 to February 2011). The strategy included the following text terms and combinations of these: IVIg, intravenous immune globulin, intravenous immunoglobulin, immunoglobulin, immunoglobulin therapy, pentaglobin, sepsis, inflammation, immune modulation, apoptosis. Preclinical and extrapolated clinical data of IVIg therapy in sepsis suggests improved bacterial clearance, inhibitory effects upon upstream mediators of the host response (for example, the nuclear factor kappa B (NF-κB) transcription factor), scavenging of downstream inflammatory mediators (for example, cytokines), direct anti-inflammatory effects mediated via Fcγ receptors, and a potential ability to attenuate lymphocyte apoptosis and thus sepsis-related immunosuppression. Characterizing the trajectory of change in immunoglobulin levels during sepsis, understanding mechanisms contributing to these changes, and undertaking IVIg dose-finding studies should be performed prior to further large-scale interventional trials to enhance the likelihood of a successful outcome.

Comparison of flow cytometry with other modalities in the diagnosis of myelodysplastic syndrome.

INTRODUCTION: The myelodysplastic syndromes (MDSs) are heterogeneous myeloid malignancies, conventionally diagnosed by cytomorphology and cytogenetics, with an emerging role for flow cytometry. This study compared the performance of a 4-parameter flow cytometry scoring system, the Ogata Score, with other modalities in the diagnosis of MDS. METHODS: Bone marrow aspirate and trephine biopsies from 238 patients performed to assess for possible MDS were analysed, and the flow cytometry score was retrospectively applied. The sensitivity and specificity of the flow cytometry score, the aspirate microscopy, the trephine microscopy with immunohistochemistry, and cytogenetic and molecular results were determined relative to the final diagnosis. RESULTS: The medical records of the 238 patients were reviewed to determine the final clinical diagnosis made at the time of the bone marrow examination. This final diagnosis of MDS, possible MDS or not MDS, was based on clinical features and laboratory tests, including all parameters of the bone marrow investigation, except for the flow cytometry score, which was only determined for this study. The flow cytometry score was 67.4% sensitive and 93.8% specific. Aspirate microscopy had higher sensitivity (83.7%) and similar specificity (92.0%), whereas trephine microscopy had similar sensitivity (66.3%) and specificity (89.4%) to flow cytometry. Although the flow cytometry score had a lower sensitivity than aspirate microscopy, in 18 patients (7.6% of the total) the flow cytometry score was positive for MDS, whereas aspirate microscopy was negative or inconclusive. CONCLUSION: The flow cytometry score and trephine microscopy exhibited reasonable sensitivity and high specificity, and complement aspirate microscopy in the assessment of MDS.

Comparison of Sinonasal Histopathological Changes in Biological Treatment of Eosinophilic Chronic Rhinosinusitis.

BACKGROUND: Biologic therapies such as mepolizumab and benralizumab are currently utilised in the treatment of eosinophilic asthma, and are emerging in the management of eosinophilic chronic rhinosinusitis (eCRS). These biologics inhibit the interaction of IL-5 with its receptor, thus impairing cytokine signalling and eosinophil inflammation. Mepolizumab does so by targeting IL-5, whereas benralizumab targets the α chain of the IL-5 receptor. This study compares the sinonasal tissue response to anti-IL-5 biologic therapies in patients with eCRS. METHODS: A cross-sectional study of adult eCRS patients who had completed at least 2 cycles of biologic therapy and underwent endoscopic sinus surgery as part of their management were included. Sinonasal mucosal tissue biopsies were obtained intraoperatively and assessed with structured histopathological examination. Comparisons of tissue histopathology outcomes following treatment with mepolizumab or benralizumab were performed. RESULTS: 18 patients (age 49.6 ± 14.2 years, 47% female, 100% co-morbid asthma) were included in this study, comprising 10 patients managed with mepolizumab and 8 patients managed with benralizumab. Even after mepolizumab, the tissue had predominantly eosinophilic inflammation compared to benralizumab (90% v 0%, p < 0.01), which demonstrated a greater lymphoplasmacytic inflammation (10% v 75%, χ2(2) = 14.53, p < 0.01). Compared with benralizumab, mepolizumab had increased tissue eosinophil count (100% v 37.5% >10 eosinophils/HPF, τb = -8.47, p < 0.001) and more severe subepithelial oedema (80% v 37.5% severe, τb = -2.37, p = 0.02). CONCLUSION: Tissue histopathologic outcomes reflect the differing mechanism of action of mepolizumab and benralizumab in eCRS. Further analysis at the tissue level will provide further information to guide application of mAbs in type 2 inflammatory diseases.

Genomic screening by 454 pyrosequencing identifies a new human IGHV gene and sixteen other new IGHV allelic variants.

Complete and accurate knowledge of the genes and allelic variants of the human immunoglobulin gene loci is critical for studies of B cell repertoire development and somatic point mutation, but evidence from studies of VDJ rearrangements suggests that our knowledge of the available immunoglobulin gene repertoire is far from complete. The reported repertoire has changed little over the last 15 years. This is, in part, a consequence of the inefficiencies involved in searching for new members of large, multigenic gene families by cloning and sequencing. The advent of high-throughput sequencing provides a new avenue by which the germline repertoire can be explored. In this report, we describe pyrosequencing studies of the heavy chain IGHV1, IGHV3 and IGHV4 gene subgroups in ten Papua New Guineans. Thousands of 454 reads aligned with complete identity to 51 previously reported functional IGHV genes and allelic variants. A new gene, IGHV3-NL1*01, was identified, which differs from the nearest previously reported gene by 15 nucleotides. Sixteen new IGHV alleles were also identified, 15 of which varied from previously reported functional IGHV genes by between one and four nucleotides, while one sequence appears to be a functional variant of the pseudogene IGHV3-25. BLAST searches suggest that at least six of these new genes are carried within the relatively well-studied populations of North America, Europe or Asia. This study substantially expands the known immunoglobulin gene repertoire and demonstrates that genetic variation of immunoglobulin genes can now be efficiently explored in different human populations using high-throughput pyrosequencing.

Evaluation of Diffuse Type 2 Dominant or Eosinophilic Chronic Rhinosinusitis With Corticosteroid Irrigation After Surgical Neosinus Cavity Formation.

Importance: Eosinophilic chronic rhinosinusitis (eCRS), contemporarily classified as diffuse type 2 dominant chronic rhinosinusitis (CRS), is characterized by eosinophil-dominant mucosal inflammation. Contemporary management of eCRS as an inflammatory airway condition is multimodal with corticosteroid irrigations after the surgical creation of a neosinus cavity. Objectives: To assess long-term treatment outcomes in patients with primary diffuse type 2 CRS or eCRS receiving multimodal treatment. Design, Setting, and Participants: A prospective cohort study of patients seen in a tertiary rhinology practice recruited from May 2010 to November 2018 was conducted. Follow-up duration was 12 months or more following endoscopic sinus surgery (ESS) with a neosinus cavity formed. Data analysis was performed from August to November 2020. Consecutive adult (≥18 years) patients diagnosed with primary diffuse type 2 dominant CRS or eCRS based on the European Position Paper on Rhinosinusitis and Nasal Polyps 2020 criteria were included. Type 2 inflammation was defined as more than 10 eosinophils per high-power field obtained from sinus mucosal biopsy and managed with neosinus cavity ESS and ongoing corticosteroid irrigations. Exclusion criteria were less than 12 months of follow-up and secondary CRS. Interventions: Endoscopic sinus surgery with complete removal of intersinus bony partitions to create a neosinus cavity. Nasal irrigation (240 mL) with betamethasone, 1 mg, or budesonide, 1 mg, daily for 3 to 6 months after ESS and tapered to an as-needed basis (minimum, 2-3 per week). Main Outcomes and Measures: Poor control was defined as polyp recurrence (polyp growth in >1 sinus area on a single side), use of long-term systemic therapy (biologic therapy or ≥3 consecutive months of oral corticosteroids), and revision surgery involving polypectomy. The disease in patients with no poor control criteria was defined as well controlled, and the disease in those with 1 or more criteria was considered poorly controlled. Maintenance medical therapy use and patient-reported outcomes based on the 22-item Sinonasal Outcomes Test for preoperative and last follow-up were collected. Results: Of the 222 participants recruited with primary diffuse type 2 dominant CRS or eCRS and minimum of year of follow-up, 126 were men (56.8%). Mean (SD) age was 54.8 (13.6) years, and median (SD) follow-up was 2.2 (2.2) years. Of the 222 patients, 195 (87.8%) had well-controlled disease, 16 (7.2%) had polyp recurrence, 7 (3.2%) continued to receive long-term oral corticosteroid therapy, 5 (2.3%) received biologic therapy, and 8 (3.6%) underwent a revision polypectomy. Clinically meaningful change on the 22-item Sinonasal Outcomes Test and the nasal subdomain score was maintained at the last follow-up in 134 patients (67.0%). Poor disease control was not associated with poor adherence to irrigation use. Conclusions and Relevance: The findings of this cohort study suggest that long-term disease control and reduction in symptom burden in patients with primary diffuse type 2 CRS or eCRS might be achieved when managed as an inflammatory disorder. Maintenance corticosteroid irrigations in the population examined appeared to be successfully self-tapered to disease activity.

Topography of polyp recurrence in eosinophilic chronic rhinosinusitis.

BACKGROUND: Eosinophilic chronic rhinosinusitis (eCRS) is an inflammatory endotype of CRS. Contemporary treatment includes creation of a "neo-sinus" cavity and postoperative corticosteroid irrigations. Not all patients gain control with local therapy. This study aims to determine, in patients with polyp recurrence, the most common sinuses involved. METHODS: A prospective case-series was conducted on consecutive adult (≥18 years) post-FESS eCRS patients followed for a minimum of 12 months. All patients had a neo-sinus cavity created surgically and used corticosteroid irrigations daily for 3-6 months, then tapered to disease control. Sinus cavities were assessed by endoscopy on last follow-up. Polyp recurrence was defined as a score of 5 or 6 in the MLMES in ≥3 sinus cavities. Patient-reported outcomes based on SNOT22 and NSS, frequency of corticosteroid irrigations, and courses of systemic antibiotics and corticosteroid were collected. The pattern of sinus involvement was analyzed. RESULT: A total of 342 sinus cavities were assessed (mean ± standard deviation, 54.9 ± 13.4 years, 43.2% female). Polyp recurrence occurred in 4.3% (6.4% of patients, n = 7 unilateral) of sinus cavities. Frontal and ethmoid sinus cavities were most affected in those with polyp recurrence, compared to the maxilla and sphenoid (100% vs 100% vs 53% vs 53%, p < 0.01). Although those patients with polyp recurrence utilized more systemic corticosteroids courses per year (0.4 ± 0.4 vs 0.1 ± 0.3, p < 0.01), the use of corticosteroid irrigations was similar (% >4/week; 66.7% vs 48.9%, p = 0.13). Prior surgery was more common in patients with polyp recurrence (86.7% vs 53.5%, p = 0.01). CONCLUSION: The frontal and ethmoid sinuses were most affected in those patients with polyp recurrence. Whether the disease is more active in this location or topical therapy has limited access requires further evaluation.

Differential rates of apoptosis and recruitment limit eosinophil accumulation in the lungs of asthma-resistant CBA/Ca mice.

The accumulation of eosinophils is a common feature of allergic airway inflammation and correlates with disease severity. In an ovalbumin (OVA)-induced murine model of allergic lung disease, CBA/Ca mice develop much lower levels of lung eosinophilia, lung oedema, mucus hypersecretion and airways obstruction than BALB/c and C57BL/6 strains. In this study these strains have been examined to identify mechanisms that control the recruitment and survival of eosinophils in the allergic lung. Following immunization with OVA, CBA/Ca mice developed a robust systemic allergic response, with high levels of total and OVA-specific IgE and increases in peripheral blood eosinophils. Lung eotaxin-1 levels and expression of CD18 on eosinophils recovered by bronchoalveolar lavage (BAL) were least pronounced in CBA/Ca mice, whereas mRNA for L-selectin was highest in eosinophils from C57BL/6 mice. Apoptosis of BAL eosinophils ex vivo was most pronounced in the CBA/Ca strain. BALB/c mice expressed the highest levels of the eosinophil growth and survival factor interleukin (IL)-5 in the lungs and BAL eosinophils from these animals expressed more of the anti-apoptotic proteins Bcl-xL and Bcl-2 than cells from the other strains. A combination of lower levels of recruitment and rapid apoptosis may therefore limit the accumulation of eosinophils and pathology in the lungs of CBA/Ca mice. In addition, although the level of pathology that developed in C57BL/6 and BALB/c mice was similar, some of the underlying mechanisms are likely to differ.

Atopy in chronic rhinosinusitis: impact on quality of life outcomes.

BACKGROUND: Chronic rhinosinusitis (CRS), in particular with nasal polyps (CRSwNP), has been linked with skewed T-helper 2 and immunoglobulin E (IgE)-mediated allergic responses. The role of atopy in CRS, however, remains unclear. Correlations between immunological allergic markers and patient-reported outcomes measures (PROMs) were investigated. METHODS: A cross-sectional study of adult patients with CRS undergoing endoscopic sinus surgery was conducted. Immunological allergic markers included automated immunoassay testing for serum-specific IgE to common allergens (house dust mite, grass, mold, animal epithelia) and total IgE. PROMs were assessed using the 22-item Sino-Nasal Outcome Test (SNOT-22). Patients were defined as atopic based on either a positive specific IgE or elevated total IgE (>160 kU/L). RESULTS: A total of 446 patients (45.7% female, age 49.05 ± 14.96 years) were recruited, of which 42.8% had asthma, 51.6% had CRSwNP, and 63.0% had eosinophilic CRS. Positive allergen sensitization was detected in 52.9% patients. Total IgE levels were elevated in 28.0% with mean IgE level of 161 ± 269 kU/L. Atopy was associated with younger age at the time of surgery, CRSwNP, asthma, and eosinophilic CRS (eCRS). Atopy was also associated with increased severity in nasal symptom score (13.1 ± 6.4 vs 11.9 ± 6.0, p = 0.04), as well as worse scores in the loss of smell/taste (χ2 (1) = 5.97, p = 0.02) and need to blow nose (χ2 (1) = 4.26, p = 0.04) questions in the CRS population. In the CRSwNP population, there was no significant association between atopy and PROMs. CONCLUSION: Comorbid atopy in CRS is associated with additional symptom burden, reflected mainly within the nasal symptom quality of life markers. Atopy assessment in CRS is important to ensure appropriate and successful treatment of the disease.

Turbinate-Specific IgE in Normal and Rhinitic Patients.

BACKGROUND: Specific immunoglobulin E (sIgE) within the nasal airway is likely to be the most ideal marker of allergic status, but little is known of the normative values in asymptomatic patients and those with rhinitis. OBJECTIVE: The aim of this study was to assess the diagnostic characteristics of inferior turbinate tissue biopsy sIgE in asymptomatic and rhinitic patients. METHODS: A diagnostic cross-sectional study was undertaken, involving patients who underwent inferior turbinate surgery with or without other surgical interventions. Inferior turbinate tissue biopsy was performed during surgery and was assessed for allergen sIgE (dust mite, grass [temperate or subtropical], and animal epithelium) using an automated immunoassay. Tissue sIgE was assessed among asymptomatic patients and those with nasal symptoms. Data were presented as median (interquartile range). A receiver operating curve was used to predict the diagnostic utility of turbinate tissue sIgE in determining allergic rhinitis. RESULTS: A total of 160 patients (41.89 ± 14.65 years, 36.9% females) were included. The median tissue sIgE concentration among the asymptomatic nonatopic group of patients was 0.09 (0.08-0.10) kUA/L and tissue sIgE > 0.10 kUA/L was determined as a positive threshold. Inferior turbinate tissue sIgE was shown to be a predictive test for allergic rhinitis (area under curve: 0.87, 95% confidence interval: 0.84-0.90) with 90% sensitivity and 89% negative predictive value. CONCLUSION: Inferior turbinate tissue biopsy sIgE is a sensitive tool to predict allergic rhinitis. The threshold value of 0.1 kUA/L corresponded well with the asymptomatic nonatopic group of patients. This method detects sIgE in the nasal mucosa and may be a useful test for allergic rhinitis in future research.

The reported germline repertoire of human immunoglobulin kappa chain genes is relatively complete and accurate.

We describe a bioinformatic analysis of germline and rearranged immunoglobulin kappa chain (IGK) gene sequences, performed in order to assess the completeness and reliability of the reported IGK repertoire. In contrast to the reported heavy-chain gene repertoire, which includes many dubious sequences, only five IGK variable gene (IGKV) alleles appear to have been reported in error. There was, however, insufficient evidence to justify removing these IGKV genes from the germline repertoire. Bioinformatic analysis of apparent mismatches between reported germline genes and 1,863 expressed IGK sequences suggested the existence of two unreported IGKV polymorphisms. Genomic screening of 12 individuals led to the confirmation of both of these polymorphisms, IGKV1-16*02 and IGKV2-30*02. We also show that in contrast to the heavy chain, the IGK repertoire is dominated by sequences that use just a handful of kappa variable (IGKV) and junction (IGKJ) gene pairs. There is also little modification of IGKV and IGKJ genes by the processes of exonuclease removal and N nucleotide addition. The expressed IGK repertoire therefore lacks diversity and the junction region is particularly constrained. Remarkably, the analysis of a dataset of 435 relatively unmutated rearranged kappa genes showed that ten amino acid sequences account for almost 10% of the rearrangements, with identical sequences being derived from as many as seven independent sources. Such dominant sequences are likely to have important roles in the operation of the humoral immune response.

Mechanisms in allergic airway inflammation - lessons from studies in the mouse.

Asthma is a chronic inflammatory disease of the airways, involving recurrent episodes of airway obstruction and wheezing. A common pathological feature in asthma is the presence of a characteristic allergic airway inflammatory response involving extensive leukocyte infiltration, mucus overproduction and airway hyper-reactivity. The pathogenesis of allergic airway inflammation is complex, involving multiple cell types such as T helper 2 cells, regulatory T cells, eosinophils, dendritic cells, mast cells, and parenchymal cells of the lung. The cellular response in allergic airway inflammation is controlled by a broad range of bioactive mediators, including IgE, cytokines and chemokines. The asthmatic allergic inflammatory response has been a particular focus of efforts to develop novel therapeutic agents. Animal models are widely used to investigate inflammatory mechanisms. Although these models are not perfect replicas of clinical asthma, such studies have led to the development of numerous novel therapeutic agents, of which some have already been successful in clinical trials.