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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Germline-activating mutations in PIK3CD compromise B cell development and function.

Gain-of-function (GOF) mutations in PIK3CD, encoding the p110δ subunit of phosphatidylinositide 3-kinase (PI3K), cause a primary immunodeficiency. Affected individuals display impaired humoral immune responses following infection or immunization. To establish mechanisms underlying these immune defects, we studied a large cohort of patients with PIK3CD GOF mutations and established a novel mouse model using CRISPR/Cas9-mediated gene editing to introduce a common pathogenic mutation in Pik3cd In both species, hyperactive PI3K severely affected B cell development and differentiation in the bone marrow and the periphery. Furthermore, PI3K GOF B cells exhibited intrinsic defects in class-switch recombination (CSR) due to impaired induction of activation-induced cytidine deaminase (AID) and failure to acquire a plasmablast gene signature and phenotype. Importantly, defects in CSR, AID expression, and Ig secretion were restored by leniolisib, a specific p110δ inhibitor. Our findings reveal key roles for balanced PI3K signaling in B cell development and long-lived humoral immunity and memory and establish the validity of treating affected individuals with p110δ inhibitors.

Systemic Predictors of Eosinophilic Chronic Rhinosinusitis.

Background Eosinophilic chronic rhinosinusitis (eCRS) is linked with skewed T-helper 2 or immunoglobulin E (IgE)-mediated allergic responses, with differing diagnosis, prognosis, and management to non-eCRS. Objective The association between biomarkers and eCRS was investigated to assess the predictors of eCRS. Methods A cross-sectional study of adult patients with chronic rhinosinusitis (CRS) undergoing endoscopic sinus surgery was conducted. eCRS was defined by histopathological assessment showing >10 eosinophils/high-power field on sinus mucosal biopsy. Blood tests were performed preoperatively and assessed for a full blood count including eosinophils and a white cell count (WCC) as well as biochemical markers of inflammation and atopy including Immunoglobulin E (IgE), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and ImmunoCAP testing for serum-specific IgE. Comparisons between eCRS and non-eCRS patients were performed. Results 345 patients (48.1% female, age 48.72 ± 15.06 years) were recruited, with 206 (59.7%) identified as eCRS, 41% with asthma and 47% CRS with nasal polyps. eCRS patients were more likely to have asthma ( P < .01) and nasal polyps ( P < .01). Blood eosinophils were significantly elevated in eCRS (0.42±0.34 vs 0.17±0.13 × 109/L, P < .01) as were eosinophils as a ratio of WCC (6.21 ± 4.48 vs 2.55 ± 1.84, P < .01). ESR was decreased when compared with non-eCRS (8.1±7.87 vs 10.65±11.91, P = .03). Receiver operating characteristic curve analysis predicted high tissue eosinophilia at blood eosinophil levels above 0.24 × 109/L (sensitivity 70.9%, specificity 78.4%, area under the curve [AUC]: 0.792, P < .01). eCRS was predicted at eosinophil above 4.27% of total WCC (sensitivity 64.1%, specificity 88.5%, AUC 0.797; P < .01; positive predictive value 89.2%, negative predictive value 62.4%, positive likelihood ratio 5.57, and diagnostic odds ratio 13.71). There was no significant association among WCC, CRP, IgE, or ImmunoCAP testing. Conclusion eCRS is associated with elevated blood eosinophils (>0.24 × 109/L), eosinophil ratio (>4.27% of total WCC), and lower ESR when compared with non-eCRS.

Positive allergen reaction in allergic and nonallergic rhinitis: a systematic review.

BACKGROUND: The diagnosis of allergic rhinitis (AR) is based on cutaneous and serological assessment to determine immunoglobulin E (IgE)-mediated disease. However, discrepancies between these tests and nasal provocation exist. Patients diagnosed as non-allergic rhinitis (NAR) but with positive nasal allergen provocation test (NAPT) may represent a local allergic condition or entopy, still suitable to allergy interventions. The objective of this study was to determine the frequency of nasal reactivity toward allergens among AR and NAR patients, and to describe the diagnostic characteristics of NAPT methodologies. METHODS: EMBASE (1947-) and Medline (1946-) were searched until December 8, 2015. A search strategy was used to identify studies on AR or NAR patients subjected to diagnostic local nasal provocation. All studies providing original NAPT data among the AR or NAR population were included. Meta-analysis of proportion data was presented as a weighted probability % (95% confidence interval [CI]). RESULTS: The search yielded 4504 studies and 46 were included. The probability of nasal allergen reactivity for the AR population was 86.3% (95% CI, 84.4 to 88.1) and in NAR was 24.7% (95% CI, 22.3 to 27.2). Reactivity was high with pollen for both AR 97.1% (95% CI, 94.2 to 99.2) and NAR 47.5% (95% CI, 34.8 to 60.4), and lowest with dust for both AR 79.1% (95% CI, 76.4 to 81.6) and NAR 12.2% (95% CI, 9.9 to 14.7). NAPT yielded high positivity when defined by subjective end-points: AR 91.0% (95% CI, 86.6 to 94.8) and NAR 30.2% (95% CI, 22.9 to 37.9); and lower with objective end-points: AR 80.8% (95% CI, 76.8 to 84.5) and NAR 14.1% (95% CI, 11.2 to 17.2). CONCLUSION: Local allergen reactivity is demonstrated in 26.5% of patients previously considered non-allergic. Similarly, AR, when defined by skin-prick test (SPT) or serum specific IgE (sIgE), may lead to 13.7% of patients with inaccurate allergen sensitization or non-allergic etiologies.

Polychromatic flow cytometry is more sensitive than microscopy in detecting small monoclonal plasma cell populations.

BACKGROUND: There is an emerging role for flow cytometry (FC) in the assessment of small populations of plasma cells (PC). However, FC's utility has been questioned due to consistent underestimation of the percentage of PC compared to microscopy. METHODS: A retrospective study was performed on bone marrow samples analysed by 8-colour FC. Plasma cell populations were classified as polyclonal or monoclonal based on FC analysis. FC findings were compared with microscopy of aspirates, histology and immunohistochemistry of trephine biopsies, and immunofixation (IFX) of serum and/or urine. RESULTS: FC underestimated PC compared to aspirate and trephine microscopy. The 10% diagnostic cutoff for MM on aspirate microscopy corresponded to a 3.5% cutoff on FC. Abnormal plasma cell morphology by aspirate microscopy and clonality by FC correlated in 229 of 294 cases (78%). However, in 50 cases, FC demonstrated a monoclonal population but microscopy reported no abnormality. In 15 cases, abnormalities were reported by microscopy but not by FC. Clonality assessment by trephine microscopy and FC agreed in 251/280 cases (90%), but all 29 discordant cases were monoclonal by FC and not monoclonal by microscopy. These cases had fewer PC and proportionally more polyclonal PC, and when IFX detected a paraprotein, it had the same light chain as in the PC determined by FC. CONCLUSIONS: FC was more sensitive in detecting monoclonal populations that were small or accompanied by polyclonal PC. This study supports the inclusion of FC in the evaluation of PC, especially in the assessment of small populations. © 2016 International Clinical Cytometry Society.

Using calculated globulin fraction to reduce diagnostic delay in primary and secondary hypogammaglobulinaemias: results of a demonstration project.

BACKGROUND: Median diagnostic delay of five to six years seen in primary hypogammaglobulinaemia results in morbidity including bronchiectasis. Patients typically have multiple health care encounters and blood tests before the diagnosis is considered. We report outcomes from using the difference between total protein and albumin (globulin fraction) to reduce diagnostic delay in unsuspected hypogammaglobulinaemia. METHODS: A prospective >5 year programme in the setting of a National Health Services Hospital Blood Sciences pathology service processing serum samples from primary and secondary care. Patients with globulin fraction below the first percentile were reviewed in the context of supplied clinical details. Immunoglobulin measurements were performed in selected patients. RESULTS: Of 2,910,850 globulin fractions 27,304 (0.9%) were below the 1st percentile globulin fraction (<18 g/L). After exclusions, 933 (3% of these) had immunoglobulins measured. Of these, 292 had IgG < 5 g/L, 186 < 4 g/L and 80 < 3 g/L, giving respective positive predictive values of 31%, 20% and 8.6%. Positive predictive value for common variable immunodeficiency was 1.3%. We identified 12 new cases of common variable immunodeficiency, 10 new haematological disorders and 20 hypogammaglobulinaemias secondary to medication. Locally derived cut-offs are required as small differences between analysers have a significant effect on screen-positive rates. CONCLUSIONS: Use of a 1st percentile globulin fraction improved early detection of hypogammaglobulinaemia. This is a useful adjunct to alert clinicians to unsuspected hypogammaglobulinaemia but should not replace immunoglobulin measurement. Patients with globulin fraction below the first percentile should be reviewed for possible hypogammaglobulinaemia.

IgE-associated IGHV genes from venom and peanut allergic individuals lack mutational evidence of antigen selection.

Antigen selection of B cells within the germinal center reaction generally leads to the accumulation of replacement mutations in the complementarity-determining regions (CDRs) of immunoglobulin genes. Studies of mutations in IgE-associated VDJ gene sequences have cast doubt on the role of antigen selection in the evolution of the human IgE response, and it may be that selection for high affinity antibodies is a feature of some but not all allergic diseases. The severity of IgE-mediated anaphylaxis is such that it could result from higher affinity IgE antibodies. We therefore investigated IGHV mutations in IgE-associated sequences derived from ten individuals with a history of anaphylactic reactions to bee or wasp venom or peanut allergens. IgG sequences, which more certainly experience antigen selection, served as a control dataset. A total of 6025 unique IgE and 5396 unique IgG sequences were generated using high throughput 454 pyrosequencing. The proportion of replacement mutations seen in the CDRs of the IgG dataset was significantly higher than that of the IgE dataset, and the IgE sequences showed little evidence of antigen selection. To exclude the possibility that 454 errors had compromised analysis, rigorous filtering of the datasets led to datasets of 90 core IgE sequences and 411 IgG sequences. These sequences were present as both forward and reverse reads, and so were most unlikely to include sequencing errors. The filtered datasets confirmed that antigen selection plays a greater role in the evolution of IgG sequences than of IgE sequences derived from the study participants.