IgA and IgG antineutrophil cytoplasmic antibody engagement of Fc receptor genetic variants influences granulomatosis with polyangiitis.

Granulomatosis with polyangiitis (Wegener's) is a rare autoimmune neutrophil-mediated vasculitis that can cause renal disease and mucosal manifestations. Antineutrophil cytoplasmic antibodies (ANCA) are present in many patients, vary in level over time, and induce neutrophil activation through engagement with Fc receptors (FcRs). Given roles for FcRs in ANCA-mediated neutrophil activation and IgA antibodies in mucosal immunity, we hypothesized that FcR genetics and previously unappreciated IgA ANCA affect clinical presentation. We assembled a total of 673 patients and 413 controls from two multicenter cohorts, performed ELISA and immunofluorescence assays to determine IgA and IgG ANCA positivity, and used Illumina, TaqMan, or Pyrosequencing to genotype eight haplotype-tagging SNPs in the IgA FcR (FCAR) and to determine NA1/NA2 genotype of FCGR3B, the most prevalent neutrophil IgG FcR. We evaluated neutrophil activation by measuring degranulation marker CD11b with flow cytometry or neutrophil extracellcular trap formation with confocal microscopy. Functional polymorphisms in FCGR3B and FCAR differed between patient groups stratified by renal involvement. IgA ANCA were found in ∼30% of patients and were less common in patients with severe renal disease. Neutrophil stimulation by IgA or IgG ANCA led to degranulation and neutrophil extracellcular trap formation in a FcR allele-specific manner (IgA:FCAR P = 0.008; IgG:FCGR3B P = 0.003). When stimulated with IgA and IgG ANCA together, IgG ANCA induced neutrophil activation was reduced (P = 0.0001). FcR genotypes, IgA ANCA, and IgG ANCA are potential prognostic and therapeutic targets for understanding the pathogenesis and presentation of granulomatosis with polyangiitis (Wegener's).

Bacillus cereus septicemia attributed to a matched unrelated bone marrow transplant.

BACKGROUND: Hematopoietic cell transplantation (HCT) is performed in more than 25,000 patients annually. Clinically significant bacterial transmission from HCT products is rare. CASE REPORT: A 36-year-old male of Asian descent with chronic myelogenous leukemia developed sepsis leading to acute renal failure and disseminated intravascular coagulation during infusion of matched unrelated donor bone marrow. This product later tested positive for Bacillus cereus. DISCUSSION: This HCT product traveled 31 hours at room temperature before arriving at the transplant center. Reducing transport times, transporting at 4 °C, and enhancing bacterial surveillance of HCT products may increase the ability to detect bacterial proliferation from transport. CONCLUSION: To prevent a similar case in the future, we will begin Gram staining all HCT products in transit more than 24 hours to alert physicians of the need for prophylactic antibiotic therapy.

An African ancestry-specific allele of CTLA4 confers protection against rheumatoid arthritis in African Americans.

Cytotoxic T-lymphocyte associated protein 4 (CTLA4) is a negative regulator of T-cell proliferation. Polymorphisms in CTLA4 have been inconsistently associated with susceptibility to rheumatoid arthritis (RA) in populations of European ancestry but have not been examined in African Americans. The prevalence of RA in most populations of European and Asian ancestry is approximately 1.0%; RA is purportedly less common in black Africans, with little known about its prevalence in African Americans. We sought to determine if CTLA4 polymorphisms are associated with RA in African Americans. We performed a 2-stage analysis of 12 haplotype tagging single nucleotide polymorphisms (SNPs) across CTLA4 in a total of 505 African American RA patients and 712 African American controls using Illumina and TaqMan platforms. The minor allele (G) of the rs231778 SNP was 0.054 in RA patients, compared to 0.209 in controls (4.462 x 10(-26), Fisher's exact). The presence of the G allele was associated with a substantially reduced odds ratio (OR) of having RA (AG+GG genotypes vs. AA genotype, OR 0.19, 95% CI: 0.13-0.26, p = 2.4 x 10(-28), Fisher's exact), suggesting a protective effect. This SNP is polymorphic in the African population (minor allele frequency [MAF] 0.09 in the Yoruba population), but is very rare in other groups (MAF = 0.002 in 530 Caucasians genotyped for this study). Markers associated with RA in populations of European ancestry (rs3087243 [+60C/T] and rs231775 [+49A/G]) were not replicated in African Americans. We found no confounding of association for rs231778 after stratifying for the HLA-DRB1 shared epitope, presence of anti-cyclic citrullinated peptide antibody, or degree of admixture from the European population. An African ancestry-specific genetic variant of CTLA4 appears to be associated with protection from RA in African Americans. This finding may explain, in part, the relatively low prevalence of RA in black African populations.

Oncology Patients Who Develop Transfusion-Associated Circulatory Overload: An Observational Study.

BACKGROUND: Transfusion-associated circulatory overload (TACO) is a largely preventable transfusion complication that results in significant morbidity and mortality. Cancers, related treatments, and comorbidities are among the factors that can predispose patients to TACO, but currently there are limited data on this topic in the literature. METHODS: We collected data retrospectively from the electronic health records of 93 adult patients with cancer who met Centers for Disease Control and Prevention (CDC) criteria for TACO from July 1, 2019, through October 31, 2020. The parameters we studied included demographics, comorbidities, treatment modalities, transfusion practices, and outcomes. We summarized data by means and ranges for continuous variables, and proportions for categorical variables. RESULTS: During the study period, the incidence of TACO among oncology patients was 0.84 per 1000 transfusions (95% CI, 0.68-1.02), representing 6.6% of all reactions. This percentage is high, compared with 1%-6% among other populations. Unique characteristics such as hematology malignancy (75.3%), receipt of cardiotoxic chemotherapy (87.1%), pneumonia (57.0%), preexisting oxygen use (59.1%), dyspnea (62.4%), hypertension (55.9%), renal insufficiency (46.2%), daily use of corticosteroids (43.0%), daily use of diuretics (40.9%), daily use of beta-blockers (36.6%), and elevated NT-proBNP (33.3%) were frequently observed in these group of oncology patients. CONCLUSIONS: Our study indicates that oncology patients have unique factors that may lead to diagnosis of TACO. Developing appropriate guidelines that apply to oncology patients, in addition to those set forth by the CDC, should be considered. Implementation by ordering healthcare providers of a tools that can predict TACO can help in early recognition and mitigation of TACO.

Most common single-nucleotide polymorphisms associated with rheumatoid arthritis in persons of European ancestry confer risk of rheumatoid arthritis in African Americans.

OBJECTIVE: Large-scale genetic association studies have identified >20 rheumatoid arthritis (RA) risk alleles among individuals of European ancestry. The influence of these risk alleles has not been comprehensively studied in African Americans. We therefore sought to examine whether these validated RA risk alleles are associated with RA risk in an African American population. METHODS: Twenty-seven candidate single-nucleotide polymorphisms (SNPs) were genotyped in 556 autoantibody-positive African Americans with RA and 791 healthy African American control subjects. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for each SNP were compared with previously published ORs for RA patients of European ancestry. We then calculated a composite genetic risk score (GRS) for each individual based on the sum of all risk alleles. RESULTS: Overlap of the ORs and 95% CIs between the European and African American populations was observed for 24 of the 27 candidate SNPs. Conversely, 3 of the 27 SNPs (CCR6 rs3093023, TAGAP rs394581, and TNFAIP3 rs6920220) demonstrated ORs in the opposite direction from those reported for RA patients of European ancestry. The GRS analysis indicated a small but highly significant probability that African American patients relative to control subjects were enriched for the risk alleles validated in European RA patients (P = 0.00005). CONCLUSION: The majority of RA risk alleles previously validated for RA patients of European ancestry showed similar ORs in our population of African Americans with RA. Furthermore, the aggregate GRS supports the hypothesis that these SNPs are risk alleles for RA in the African American population. Future large-scale genetic studies are needed to validate these risk alleles and identify novel RA risk alleles in African Americans.

Wegener's granulomatosis: a model of auto-antibodies in mucosal autoimmunity.

Wegener's granulomatosis (WG) is an autoimmune condition marked by vasculitis of small and medium sized vessels particularly affecting the upper respiratory tract and kidneys. There is a strong mucosal component similar to other autoimmune conditions such as systemic lupus erythematosus and Behçet's disease. While the pathogenesis of WG is not completely known, auto-antibodies such as IgG ANCAs have been implicated in endovascular damage and modulation of neutrophil/monocyte responses by Fc receptor (FcR) signaling. Due to the substantial mucosal involvement in WG (oral, nasal, and upper respiratory tract involvement), it is probable that IgA antibodies (perhaps IgA ANCAs) play a role in disease. Given discrepancies in associating ANCA levels with disease activity, future work should determine if IgA ANCAs are present in WG patients and examine the biology underlying the ANCAs' signaling partners--the FcRs.

Transfusion reactions in pediatric and adolescent young adult haematology oncology and immune effector cell patients.

BACKGROUND: Active surveillance for transfusion reactions is critically important among pediatric patients undergoing chemotherapy. Among pediatric-adolescent-young-adult (AYA) hematology/oncology patients, who have been typically excluded from transfusion reaction studies, this profile remains poorly characterized. METHODS: We assessed the incidence and clinical characteristics of transfusion reactions (n = 3246 transfusions) in this population (n = 201 patients) at our center. FINDINGS: The incidence of adjudicated transfusion reactions was 2·04%. The incidence was higher for platelet (2·78%) compared to packed red blood cell transfusions (1·49%) (p = 0·0149). The majority (61·4%) of all reactions were classified as febrile non-haemolytic transfusion, while 35·7% were considered allergic, and 2·9% were classified as transfusion-associated circulatory overload. The incidence of transfusion reactions in patients who were pre-medicated was higher (2·51%) than in patients who were not (1·52%) (p = 0·0406). Sub-set analysis revealed a 3·95% incidence of adjudicated transfusion reactions among recipients of immune effector cells (IECs) (n = 3), all of which occurred during the potential window for cytokine release syndrome; two-thirds of these reactions were severe/potentially life-threatening. INTERPRETATION: The incidence of transfusion reactions among pediatric-AYA hematology/oncology patients may be lower than the general pediatric population. Patients with a prior history of transfusion reactions and those receiving platelet transfusions may be at higher risk for reaction. From our limited sample, IEC recipients may be at risk for severe transfusion reactions. Large multi-center prospective studies are needed to characterize transfusion reactions in this population. Appropriate characterization of reactions in this population may inform risk stratification and mitigate missed opportunities for prompt recognition and appropriate management. FUNDING: None.

Overview of COVID-19 testing and implications for otolaryngologists.

BACKGROUND: Testing for SARS-CoV-2 is important for decision making prior to surgery in otolaryngology. An understanding of current and developing testing methods is important for interpreting test results. METHODS: We performed a literature review of current evidence surrounding SARS-CoV-2 diagnostic testing highlighting its utility, limitations, and implications for otolaryngologists. RESULTS: The currently accepted RT-PCR test for SARS-CoV-2 has varying sensitivity according to which subsite of the aerodigestive tract is sampled. Nasal swab sensitivities appear to be about 70%. Chest CT imaging for screening purposes is not currently recommended. CONCLUSION: Due to the current sensitivity of RT-PCR based testing for SARS-CoV-2, a negative test cannot rule out COVID-19. Full PPE should be worn during high-risk procedures such as aerosol generating procedures even if testing is negative. Patients who test positive during screening should have their surgeries postponed if possible until asymptomatic and have tested negative for SARS-CoV-2.

Does gamma-aminobutyric acid (GABA) influence the development of chronic inflammation in rheumatoid arthritis?

BACKGROUND: Recent studies have demonstrated a role for spinal p38 MAP kinase (MAPK) in the development of chronic inflammation and peripheral arthritis and a role for GABA in the inhibition of p38 MAPK mediated effects. Integrating these data suggests that GABA may play a role in downregulating mechanisms that lead to the production of proinflammatory agents such as interleukin-1, interleukin-6, and matrix metalloproteinase 3 - agents implicated in the pathogenesis of rheumatoid arthritis (RA). Genetic studies have also associated RA with members of the p38 MAPK pathway. HYPOTHESIS: We propose a hypothesis for an inefficient GABA signaling system that results in unchecked proinflammatory cytokine production via the p38 MAPK pathway. This model also supports the need for increasing research in the integration of immunology and neuroscience.

False-positive HIV nucleic acid amplification testing during CAR T-cell therapy.

Advancements in immunotherapy have opened a new era in oncology, to include genetic modification of human T-cells to express a chimeric antigen receptor (CAR) that enables targeted tumor recognition (Kochenderfer et al., 2015; Lee et al., 2015; Maus and Levine 2016; Rosenberg et al., 2008). Herein, we report a false-positive HIV testing in a patient who had undergone CAR T-cell therapy created with a lentiviral vector.

Hematopoietic defects and iPSC disease modeling: lessons learned.

Hematopoiesis is a paradigm for stem cell biology in that it centers on differentiation of a self-renewing pluripotent precursor into multiple committed cell types with specific functions. The use of induced pluripotent stem cells (iPSCs) as a disease modeling tool has revealed numerous insights into the underlying pathophysiology of hematological diseases - those disorders arising from defective hematopoiesis. Likewise, studying hematopoiesis and the defects that can arise offer clues to understanding general stem cell survival and differentiation.

Pluripotent stem cell models of Shwachman-Diamond syndrome reveal a common mechanism for pancreatic and hematopoietic dysfunction.

Shwachman-Diamond syndrome (SDS), a rare autosomal-recessive disorder characterized by exocrine pancreatic insufficiency and hematopoietic dysfunction, is caused by mutations in the Shwachman-Bodian-Diamond syndrome (SBDS) gene. We created human pluripotent stem cell models of SDS through knockdown of SBDS in human embryonic stem cells (hESCs) and generation of induced pluripotent stem cell (iPSC) lines from two patients with SDS. SBDS-deficient hESCs and iPSCs manifest deficits in exocrine pancreatic and hematopoietic differentiation in vitro, enhanced apoptosis, and elevated protease levels in culture supernatants, which could be reversed by restoring SBDS protein expression through transgene rescue or by supplementing culture media with protease inhibitors. Protease-mediated autodigestion provides a mechanistic link between the pancreatic and hematopoietic phenotypes in SDS, highlighting the utility of hESCs and iPSCs in obtaining novel insights into human disease.

Pathways: Strategies for susceptibility genes in SLE.

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder marked by an inappropriate immune response to nuclear antigens. Recent whole genome association and more focused studies have revealed numerous genes implicated in this disease process, including ITGAM, Fc gamma receptors, complement components, C-reactive protein, and others. One common feature of these molecules is their involvement in the immune opsonin pathway and in phagocytic clearing of nuclear antigens and apoptotic debris, which provide excessive exposure of lupus-related antigens to immune cells. Analysis of gene-gene interactions in the opsonin pathway and its relationship to SLE may provide a system-based approach to identify additional candidate genes associated with disease able to account for a larger part of lupus susceptibility.

Association of IL4R single-nucleotide polymorphisms with rheumatoid nodules in African Americans with rheumatoid arthritis.

INTRODUCTION: To determine whether IL4R single-nucleotide polymorphisms (SNPs) rs1805010 (I50V) and rs1801275 (Q551R), which have been associated with disease severity in rheumatoid arthritis (RA) patients of European ancestry, relate to the presence of rheumatoid nodules and radiographic erosions in African Americans. METHODS: Two IL4R SNPs, rs1805010 and rs1801275, were genotyped in 749 patients from the Consortium for Longitudinal Evaluation of African-Americans with Early Rheumatoid Arthritis (CLEAR) registries. End points were rheumatoid nodules defined as present either by physical examination or by chest radiography and radiographic erosions (radiographs of hands/wrists and feet were scored using the modified Sharp/van der Heijde system). Statistical analyses were performed by using logistic regression modeling adjusted for confounding factors. RESULTS: Of the 749 patients with RA, 156 (20.8%) had rheumatoid nodules, with a mean age of 47.0 years, 84.6% female gender, and median disease duration of 1.9 years. Of the 461 patients with available radiographic data, 185 (40.1%) had erosions (score>0); their mean age was 46.7 years; 83.3% were women; and median disease duration was 1.5 years. Patients positive for HLA-DRB1 shared epitope (SE) and autoantibodies (rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP)) had a higher risk of developing rheumatoid nodules in the presence of the AA and AG alleles of rs1801275 (odds ratio (OR)adj=8.08 (95% confidence interval (CI): 1.60-40.89), P=0.01 and ORadj=2.97 (95% CI, 1.08 to 8.17), P=0.04, respectively). Likewise, patients positive for the HLA-DRB1 SE and RF alone had a higher risk of developing rheumatoid nodules in presence of the AA and AG alleles of rs1801275 (ORadj=8.45 (95% CI, 1.57 to 45.44), P=0.01, and ORadj=3.57 (95% CI, 1.18 to 10.76), P=0.02, respectively) and in the presence of AA allele of rs1805010 (ORadj=4.52 (95% CI, 1.20 to 17.03), P=0.03). No significant association was found between IL4R and radiographic erosions or disease susceptibility, although our statistical power was limited by relatively small numbers of cases and controls. CONCLUSIONS: We found that IL4R SNPs, rs1801275 and rs1805010, are associated with rheumatoid nodules in autoantibody-positive African-American RA patients with at least one HLA-DRB1 allele encoding the SE. These findings highlight the need for analysis of genetic factors associated with clinical RA phenotypes in different racial/ethnic populations.

Understanding Personalized Medicine in Rheumatoid Arthritis: A Clinician's Guide to the Future.

Personalized medicine refers to the utilization of technologies at the molecular level to understand disease processes and improve health outcomes. In rheumatoid arthritis (RA) some factors associated with disease outcome have been identified. These factors have not yet been integrated into a clinically useful tool to predict disease outcome in individual patients. Developments in pharmacogenomics are moving the field forward quite rapidly. Genetic variants, which may have a role in drug metabolism mediating either drug response or toxicity, have been identified for both traditional disease modifying antirheumatic drugs and biologic agents. Choosing a medication based on a patient's characteristics (sociodemographic, clinical, genetic) will result in better utilization of resources and better clinical outcomes. The ethical, political, and legal implications of personalized medicine need to be considered as well.