Arthritis autoantibodies in individuals without rheumatoid arthritis: follow-up data from a Dutch population-based cohort (Lifelines).

OBJECTIVES: To assess whether the presence of arthritis autoantibodies alongside IgG ACPA predicts clinically suspect arthralgia in ACPA-positive subjects without RA. METHODS: In the population-based Lifelines cohort (n = 40 136), 308 IgG ACPA-positive individuals without RA were present. Serum levels of IgA ACPA, IgA and IgM RF, and IgG anti-carbamylated antibodies were measured at baseline. Individuals were divided based on the Connective tissue disease Screening Questionnaire after 2 years follow-up. Antibodies to Porphyromonas gingivalis were determined at baseline and related to presence of periodontitis and joint complaints at 2 years follow-up. RESULTS: Of 308 subjects 53.6% were also seropositive for IgA ACPA, 42.2% for IgM RF, 23.7% for IgA RF and 13.6% for anti-carbamylated antibodies. We defined 75 persons with clinically suspect arthralgia at risk for RA based on CTD Screening Questionnaire at follow-up. Significantly more seropositivity for IgM RF and higher levels of IgG ACPA, IgA ACPA and IgM RF were found in clinically suspect arthralgia compared with no-clinically suspect arthralgia. In multivariate logistic regression correcting for age, gender and never smoking, positivity for three or more extra autoantibodies was significantly associated with clinically suspect arthralgia. Although levels of anti-P. gingivalis were not different between groups, they were significantly correlated to levels of both RFs, and both ACPAs in clinically suspect arthralgia. CONCLUSIONS: ACPA-positive individuals without RA who develop clinically suspect arthralgia have more and higher levels of other arthritis autoantibodies at baseline. Levels of anti-P. gingivalis are not related to self-reported periodontitis or clinically suspect arthralgia, but are correlated to arthritis autoantibodies in clinically suspect arthralgia.

Regulation of Toll-like receptor-mediated inflammatory response by microRNA-152-3p-mediated demethylation of MyD88 in systemic lupus erythematosus.

OBJECTIVE: microRNAs (miRNAs) play critical roles in embryogenesis, cell differentiation and the pathogenesis of several human diseases, including systemic lupus erythematosus (SLE). Toll-like receptors (TLRs) are also known to exert crucial functions in the immune response activation occurring in the pathogenesis of autoimmune diseases like SLE. Herein, the current study aimed to explore the potential role of miR-152-3p in TLR-mediated inflammatory response in SLE. METHODS: We determined the miR-152-3p expression profiles in CD4+ T cells and peripheral blood mononuclear cells (PBMCs) harvested from patients with SLE and healthy controls, and analyzed the correlation between miR-152-3p expression and clinicopathological parameters. CD70 and CD40L expression patterns in CD4+ T cells were assessed by RT-qPCR and flow cytometry. ChIP was adopted to determine the enrichment of DNA methyltransferase 1 (DNMT1) in the promoter region of myeloid differentiation factor 88 (MyD88). RESULTS: The obtained findings revealed that miR-152-3p was highly-expressed in CD4+ T cells and PBMCs of patients with SLE, and this high expression was associated with facial erythema, joint pain, double-stranded DNA, and IgG antibody. DNMT1 could be enriched in the MyD88 promoter, and miR-152-3p inhibited the methylation of MyD88 by targeting DNMT1. We also found that silencing miR-152-3p inhibited MyD88 expression not only to repress the autoreactivity of CD4+ T cells and but also to restrain their cellular inflammation, which were also validated in vivo. CONCLUSION: Our study suggests that miR-152-3p promotes TLR-mediated inflammatory response in CD4+ T cells by regulating the DNMT1/MyD88 signaling pathway, which highlights novel anti-inflammatory target for SLE treatment.

SERUM LEVELS OF ANTIBODIES AGAINST OXIDATION-SPECIFIC EPITOPES ARE DECREASED IN PATIENTS WITH RETINAL VEIN OCCLUSION.

PURPOSE: Oxidative stress and inflammation have been implicated in the development of retinal vein occlusion (RVO). Oxidation-specific epitopes (OSEs) represent products of oxidative stress that can trigger vascular inflammation and thrombosis. Natural occurring antibodies have been shown to bind oxidation-specific epitopes thereby inhibiting their inflammatory potential and promoting their removal. METHODS: This prospective cross-sectional study included 270 patients with RVO and 81 in-hospital control patients. We measured three types of serum levels of oxidation-specific epitope-specific immunoglobulin M and immunoglobulin G antibodies (anti-copper-oxidized LDL [CuOx-LDL], antiphosphocholine [PC], anti-malondialdehyde-modified LDL [MDA-LDL]). History of arterial hypertension, hyperlipidemia, myocardial infarction, diabetes mellitus, stroke, smoking status, and several laboratory parameters were determined to control for potential confounders. RESULTS: Compared with controls, patients with RVO had significantly lower levels of immunoglobulin M and immunoglobulin G antibodies against CuOx-LDL and PC, and significantly lower levels of immunoglobulin G but not immunoglobulin M antibodies against MDA-LDL. The association between RVO patients and lower levels of these antibodies prevailed upon multivariable adjustment. CONCLUSION: These prospective data show that antibodies against oxidation-specific epitope are lower in patients with RVO compared with control patients and support the concept that oxidative stress and inflammation play key roles in the development and subsequent complications in RVO.

Anti-carbamylated proteins antibody repertoire in rheumatoid arthritis: evidence of a new autoantibody linked to interstitial lung disease.

OBJECTIVE: To analyse the association between anti-carbamylated protein antibodies (Anti-CarP) and interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients. METHODS: Cross-sectional study including RA patients fulfilling the 2010 ACR/EULAR criteria. The main population comprised two groups: (1) RA patients diagnosed with RA-ILD (RA-ILD group); (2) RA patients without ILD (non-ILD RA group). Non-ILD RA patients in whom ILD was suspected underwent a diagnostic work-up and, if ILD was diagnosed, were switched to the RA-ILD group. ILD was diagnosed by high-resolution computed tomography and confirmed by a multidisciplinary committee. An independent replication sample was also obtained. Three Anti-CarP IgG autoantibodies against fetal calf serum (Anti-FCS), fibrinogen (Anti-Fib) and chimeric fibrine/filagrine homocitrullinated peptide (Anti-CFFHP) and one Anti-CarP IgA against FCS (Anti-FCS-IgA) were determined by home-made ELISA. Associations between Anti-CarP and ILD were analysed using multivariable logistic regression adjusted by smoking, sex, age, RA disease duration, rheumatoid factor and anticitrullinated protein antibodies. RESULTS: We enrolled 179 patients: 37 (21%) were finally diagnosed with RA-ILD. Anti-CarP specificities were more frequent in RA-ILD patients (Anti-FCS 70% vs 43%; Anti-Fib 73% vs 51%; Anti-CFFHP 38% vs 19%; Anti-CarP-IgA 51% vs 20%, p<0.05 for all comparisons). Serum titers of Anti-CarP were significantly higher in RA-ILD patients. Anti-CarP specificities showed a robust effect towards increasing the odds of ILD in the multivariate analysis (Anti-FCS (OR: 3.42; 95% CI: 1.13 to 10.40), Anti-Fib (OR: 2.85; 95% CI: 0.83 to 9.70), Anti-CFFHP (OR: 3.11; 95% CI: 1.06 to 9.14) and Anti-FCS-IgA (OR: 4.30; 95% CI: 1.41 to 13.04)). Similar findings were observed in the replication sample. CONCLUSIONS: Anti-CarP were strongly associated with ILD. The role of homocitrullination in RA-ILD merits further investigation.

Most of anti-glycolipid IgG-antibodies associated to neurological disorders occur without their IgM counterpart.

BACKGROUND: Different neurological disorders frequently display antibodies against several self-glycans. Increasing evidence supports their pathogenic role; however, far less is known about their origin. Meanwhile, antibodies recognizing non-self glycans appear in normal human serum during immune response to bacteria. METHODS: Using high performance thin layer chromatography-immunostaining, we comparatively evaluated humoral immune response (IgG and IgM immunoreactivity) against glycolipids carrying self-glycans (GM3/GM2/GM1/GD1a/GD1b/GD3/GT1b/GQ1b) and non-self glycans (Forssman/GA1/"A" blood group/Nt7) in sera from 383 patients with neurological disorders along with 87 healthy controls. RESULTS: In contrast to no healthy controls having anti-self glycan IgG antibodies, one-fifth of patients' sera had anti-self glycan IgG antibodies: remarkably, 60% of these occurred without IgM antibodies of the same specificity. Contrary to this unusual fact (anti-self glycan IgG occurrence without simultaneous presence of IgM having the same specificity ~ IgG/IgM discordance), all IgG antibodies against non-self glycans occurred simultaneously with their IgM antibody counterpart (i.e. 0% discordance). When analyzed closer, the IgG/IgM discordance frequency for anti-self glycans exhibited a dual trend: below 40% for IgG antibodies against GM2, GM1 and GD1b, and greater than 53% for IgG antibodies against the remaining self glycans. Interestingly, this discordance behavior was common to several different neurological disorders. CONCLUSIONS: Classic immunology principles indicate this anti-self glycan IgG/IgM discordance should not occur in an antibody response; its unusual presence is discussed within the "binding site drift hypothesis" context, where anti-self glycan IgG antibodies could originate from pre-existing IgG recognizing structurally-related non-self glycans.

Low seroprevalence of Zika virus infection among adults in Southern Taiwan.

BACKGROUND: We recently conducted a serosurvey of newly arrived workers in Taiwan from four Southeast Asian countries which revealed that 1% of the migrant workers had laboratory-confirmed recent Zika virus (ZIKV) infection. Taiwan, where Aedes mosquitoes are prevalent, has a close relationship with Southeast Asian countries. Up to now, 21 imported cases of ZIKV infection have been reported in Taiwan, but there has been no confirmed indigenous case. The aim of this serosurvey was to assess whether there was unrecognized ZIKV infections in Taiwan. METHODS: A total of 212 serum samples collected in a cross-sectional seroepidemiologic study conducted during the end of the 2015 dengue epidemic in Tainan, Taiwan, were analyzed. Anti-ZIKV IgM and IgG were tested using commercial enzyme-linked immunosorbent assays (ELISAs). Plaque reduction neutralization tests (PRNTs) for ZIKV and four dengue virus (DENV) serotypes were performed for samples with positive anti-ZIKV antibodies. A confirmed case of ZIKV infection was defined by ZIKV PRNT90 titer ratio ≥ 4 compared to four DENV serotypes. RESULTS: The mean age of the 212 participants was 54.0 years (standard deviation 13.7 years), and female was predominant (67.0%). Anti-ZIKV IgM and IgG were detected in 0 (0%) and 9 (4.2%) of the 212 participants, respectively. For the 9 samples with anti-ZIKV IgG, only 1 sample had 4 times higher ZIKV PRNT90 titers compared to PRNT90 titers against four dengue virus serotypes; this individual denied having traveled abroad. CONCLUSIONS: The results suggest that undetected indigenous ZIKV transmission might have occurred in Taiwan. The findings also suggest that the threat of epidemic transmission of ZIKV in Taiwan does exist due to extremely low-level of herd immunity. Our study also indicates that serological tests for ZIKV-specific IgG remain a big challenge due to cross-reactivity, even in dengue non-endemic countries.

Passenger Lymphocyte Syndrome After Pediatric Liver Transplantation.

BACKGROUND: Passenger lymphocyte syndrome (PLS) is a less known etiology of acute onset anemia following ABO-compatible (ABO-c) liver transplantation (LT). Available literature on PLS after pediatric LT is limited. Therefore, we evaluated the prevalence, clinical course, and risk factors of PLS in children following ABO-c LT. METHODS: A single-center retrospective review of all children who underwent LT between 2000 and 2017 was performed. PLS was defined as a drop-in hemoglobin >20 g/L within 30 days of LT, with positive direct antiglobulin test and 1 laboratory test confirming hemolysis. Chi square and student t tests compared variables between subjects with and without PLS. RESULTS: Amongst 333 pediatric LT performed, 51 children received an ABO-c graft. PLS was diagnosed in 7 (14%) subjects at a median of 10 days after LT. There were no significant differences in patient demographics, graft type, or immunosuppression between those who did and did not develop PLS. Recipient blood group A+ receiving a donor O+ graft was a risk factor for PLS (P = 0.015). All PLS subjects recovered with blood transfusions (median 2), and no additional interventions. Three subjects initially received recipient (instead of donor) blood group red cells. CONCLUSIONS: We report a 14% prevalence of PLS following pediatric ABO-c LT. Recipient blood group A+ receiving a donor O+ graft is a risk factor for PLS. Recognition of PLS as a cause of early acute anemia in pediatric ABO-c LT enables timely transfusion with donor (rather than recipient) blood group red cells.

One-year evaluation of clinical and immunological efficacy and safety of sublingual versus subcutaneous allergen immunotherapy in allergic conjunctivitis.

BACKGROUND: The aim of this study is to evaluate the clinical and immunological efficacy and safety of allergen immunotherapy (AIT) in patients with allergic conjunctivitis (AC) and to compare between sublingual and subcutaneous routes of administration. METHODS: A prospective comparative case series study was performed on 100 patients with IgE-mediated AC. Patients were referred to allergy clinics for skin prick test (SPT) and AIT. Patients with positive SPT and high-serum IgE level were enrolled in this study. Patients were divided into two groups: sublingual immunotherapy (SLIT) group (50 patients) and subcutaneous immunotherapy (SCIT) group (50 patients). Both groups were followed for 1 year. Efficacy was assessed clinically by comparing pre- and post-treatment symptoms and medication scores and assessed immunologically by comparing pre- and post-treatment serum IgE level and wheal diameter of SPT. Safety of the therapy was assessed by the occurrence of adverse reactions and patient tolerability to the therapy. RESULTS: Patients were either mono- or polysensitized to different allergens. Aeroallergens were significantly more common than food allergens (P = 0.00). The most prevalent aeroallergens were pollens (40%) and house dust (30%). At 12-month follow-up, both routes SLIT and SCIT led to a statistically significant clinical and immunological improvement (P < 0.05). This improvement was evident in all follow-up parameters including total ocular symptom score (TOSS), medication score, total serum IgE level, and wheal diameter of skin prick test (SPT). There was no significant difference between the two routes of administration (SLIT & SCIT) in any of the follow-up parameters (P > 0.05). Patients were able to tolerate the allergen therapy without developing any serious adverse events. CONCLUSION: Aeroallergen polysensitization is common among patients with AC. SPT should be included in the diagnostic workup of those patients. AIT is a safe and effective treatment option for patients with AC as it has the potential to achieve significant reduction in symptom and medication scores without ocular or systemic side effects. There is no significant difference between both routes of administration either SLIT or SCIT in achieving clinical and immunologic improvement; so the patient can choose his preferred method for therapy.

Preliminary assessment of anti-α-Gal IgG and IgM levels in patients with patent Plasmodium vivax infection.

Anti-α-Gal responses may exert a protective effect in falciparum malaria. However, the biological role of such antibodies is still unknown during Plasmodium vivax infections. We investigated IgG and IgM responses to α-Gal in individuals with vivax malaria. Anti-α-Gal IgG and IgM levels were higher in these patients than in controls, but no significant correlation was found between parasitaemia and anti-α-Gal response, nor between this response and ABO blood group status. This is the first study to investigate anti-α-Gal antibodies in P. vivax-infected patients; a larger survey is necessary to achieve a better understanding of host immune response during vivax malaria.

Food safety assessment and risk for toxoplasmosis in school restaurants in Armenia, Colombia.

We assessed the risk for toxoplasmosis in 10 school restaurants in Armenia (Quindio, Colombia). We analyzed the presence of Toxoplasma gondii DNA in the food, water, and living and inert surfaces of school restaurants, and we correlated these findings with the results of food safety inspection scores and with the prevalence of specific anti-T. gondii antibodies in children who ate at these restaurants. Of the 213 samples, 6.1% were positive using PCR to test for T. gondii DNA. Positive samples were found in meat, water, cucumber, guava juice, inert surfaces, and living surfaces. In 60% (6/10) of the public school restaurants, there was at least one PCR T. gondii-positive sample. In 311 serum samples from children who attended the restaurants, 101 (33%) were positive for IgG and 12 (3.9%) for IgM anti-T. gondii. The median of the compound score for the fulfillment of inspection for food safety conditions was of 60.7% (range 50-72). Higher T. gondii PCR positivity in surfaces, food, or water at each restaurant was correlated with lower inspection scores for water supply and water storage conditions. Lower scores in physical infrastructure and disinfection procedures and higher scores in furniture were correlated with a higher prevalence of IgG anti-T. gondii in children who ate at those restaurants. Inspection scores can identify restaurants with a higher risk for the presence of T. gondii.

Assessing the Sensitizing and Allergenic Potential of the Albumin and Globulin Fractions from Amaranth (Amaranthus hypochondriacus) Grains before and after an Extrusion Process.

Background: The first cases of food allergy to amaranth grain have recently been published. This pseudocereal is considered hypoallergenic, and there is scarce information about the allergenic potential of amaranth proteins, either before or after food processing. Objective: To evaluate, in a mouse model of food allergy, the sensitizing and allergenic potential of extruded and non-extruded albumin and globulin fractions from amaranth grains. Materials and Methods: Amaranth (Amaranthus hypochondriacus) flour was obtained and the albumin and globulin fractions isolated. These protein fractions were also obtained after flour extrusion. An intraperitoneal 28-day protocol was carried out to evaluate the sensitizing and allergenic potential of the proteins. The common and rarely allergenic proteins ovalbumin and potato acidic phosphatase were utilized as reference. Specific IgE and IgG antibodies were evaluated for all the proteins tested. Mast cell protease-1 (mMCP-1) responses were evaluated in serum samples collected after intragastric challenges with the proteins of interest. All serological evaluations were carried out using ELISA. Results: Mice were sensitized to the non-extruded albumin fraction from amaranth grains and to ovalbumin (p = 0.0045). The extrusion process of amaranth proteins abrogated the IgE responses triggered under non-extruded conditions (p = 0.0147). mMCP-1 responses were significantly detected in the group of mice sensitized to ovalbumin (p = 0.0138), but not in others. Conclusions: The non-extruded albumin fraction from amaranth has the potential to sensitize BALB/c mice, but this sensitizing potential fails to induce detectable serum levels of the mast cell degranulation marker mMCP-1 after intragastric challenges. Furthermore, the extrusion process abolished the sensitization potential of the amaranth albumins.

Local allergic conjunctivitis: a phenotype of allergic conjunctivitis.

PURPOSE: Local allergic rhinitis (LAR) has been reported in the field of otolaryngology; however, the concept of local allergic conjunctivitis (LAC) has not been widely studied in the ophthalmologic community. We routinely examined total IgE levels in tear fluids (t-tIgE) and antigen-specific IgE levels in serum (s-sIgE) in patients with suspected allergic conjunctivitis, on the basis of Japanese guidelines for allergic conjunctival diseases. There are several cases in which the results of t-tIgE and s-sIgE testing are divergent. We suggest that these divergent cases correspond to LAR in otolaryngology. METHODS: The study included 148 patients (33 men and 115 women) with clinical symptoms and signs of allergic conjunctivitis. Allerwatch Tear IgE® was used for measurement of t-tIgE levels. ImmunoCAP Rapid® and View Allergy 39® were used for measurement of s-sIgE levels. Conjunctival cytology using spatula was used to identify eosinophils on the conjunctiva. RESULTS: A total of 83 patients (56.1%) were positive and 65 patients were negative for t-tIgE in the AW. In the ICR, 97 patients (65.5%) were positive for at least one of the eight allergens, whereas 51 (34.5%) were negative for all allergens. Among 83 patients positive for t-tIgE, 14 (16.9%) had no detectable s-sIgE. Therefore, we considered the possibility of LAC in cases in which only local IgE could be detected. Among 28 cases (18.9%) who were negative for t-tIgE and s-sIgE, 21 underwent conjunctival scraping; eosinophils were found in four cases and eosinophilic granules in two. Accordingly, we considered the possibility of non-IgE-type AC in these six cases. CONCLUSIONS: These results suggest the existence of LAC that is a candidate of a phenotype of AC.

A Severe Anaphylactic Reaction Associated with IgM-Class Anti-Human IgG Antibodies in a Hyper-IgM Syndrome Type 2 Patient.

PURPOSE: A 42-year-old man with hyper-IgM syndrome type 2 caused by activation-induced cytidine deaminase (AID) deficiency developed a severe anaphylactic reaction to intravenous immunoglobulin. The purpose of this study was to clarify the cause of the anaphylactic reaction of the patient. METHODS: We measured IgM-class anti-human IgG and anti-human IgA antibodies in his serum by sandwich enzyme-linked immunosorbent assay (ELISA). RESULTS: The sandwich ELISA assay revealed that serum from the patient, but not the controls, reacted to three different IgG products and purified human IgA. This indicated that the patient had IgM-class anti-human IgG and IgA antibodies in his serum, which associated with the anaphylactic reactions after the administration of IgG products. The anti-IgG antibody was likely to be the main cause of the reactions because an IgA-depleted IgG product also induced a severe reaction in this case and showed high absorbance in the ELISA system, similar to other IgG products containing more IgA. CONCLUSIONS: This is the first report of IgM-class anti-human IgG associated with an anaphylactic reaction to an IgG infusion. The anaphylactic reactions were very severe in this case, probably because IgM-class antibodies are potent activators of the complement pathway.

The anti-carbamylated protein antibody response is of overall low avidity despite extensive isotype switching.

Objective: To better understand the contribution of autoantibodies in RA and the biology of their responses, we evaluated the avidity of the anti-carbamylated protein (anti-CarP) antibody response. Methods: The avidity of anti-CarP antibody, ACPA and anti-tetanus toxoid IgG were determined using elution assays. Anti-CarP IgG avidity was measured in sera of 107 RA patients, 15 paired SF and serum samples and 8 serially sampled sera before and after disease onset. Results: The avidity of anti-CarP IgG is low compared with the avidity of anti-tetanus toxoid IgG present in the same sera. Likewise, although less pronounced, anti-CarP also displayed a lower avidity as compared with the avidity of ACPA IgG. No difference in anti-CarP IgG avidity is observed between ACPA positive or ACPA negative patients. Anti-CarP IgG avidity is higher in anti-CarP IgM-negative compared with IgM-positive individuals. Furthermore, the anti-CarP avidity in serum is higher than in SF. Using samples of individuals that over time developed RA we observed no anti-CarP avidity maturation in the years before disease onset. In contrast to ACPA avidity, the anti-CarP avidity is not associated with severity of joint destruction. Conclusion: The anti-CarP response is of overall low avidity, even lower than the ACPA IgG avidity, and does not show apparent avidity maturation before or around disease onset. Overall, isotype switch and avidity maturation seem to be uncoupled as isotype switch occurs without avidity maturation, pointing towards a commonality in the regulation of both autoantibody responses as opposed to the pathways governing recall responses.

Immunogenicity and safety of pneumococcal vaccination in patients with systemic sclerosis.

Objective: To study the impact of disease and treatment with DMARDs on antibody response elicited by either pneumococcal conjugate vaccine (PCV13) or pneumococcal polysaccharide vaccine (PPV23) in patients with SSc. Methods: Forty-four SSc patients and 49 controls received a dose of either PCV13 or PPV23. Twelve patients were treated with DMARDs. Antibody levels to pneumococcal polysaccharides 6B and 23 F were measured before and 4-6 weeks after vaccination using ELISA. Antibody functionality was studied using opsonophagocytic assay performed on serotype 23 F. Results: Number of patients, percentage female and mean age (years) at vaccination were: 32, 94%, 57.5 years in SSc without DMARDs; 12, 100%, 55.5 years in SSc on DMARDs and 49, 63% and 50.6 years in controls. Post-vaccination antibody levels for both serotypes increased significantly in SSc without DMARDs and controls (P < 0.001), but in SSc on DMARDs only for 6B (P = 0.041). Compared with the other groups, patients with SSc receiving DMARDs had lower post-vaccination antibody levels for both serotypes. Opsonophagocytic assay increased significantly in all three groups. No significant difference in immunogenicity between PCV13 and PPV23 was seen. Conclusion: Pneumococcal vaccination using either PCV13 or PPV23 yielded satisfactory antibody response in SSc patients without DMARD treatment, but a lower response in patients treated with synthetic DMARDs. Type of pneumococcal vaccine (conjugate or polysaccharide) did not significantly influence antibody response. Trial registration: ClinicalTrials.gov, http://clinicaltrials.gov, NCT02240888.

Aquaporin-4 and Myelin Oligodendrocyte Glycoprotein Autoantibody Status Predict Outcome of Recurrent Optic Neuritis.

PURPOSE: To determine the aquaporin-4 and myelin oligodendrocyte glycoprotein (MOG) immunoglobulin G (IgG) serostatus and visual outcomes in patients with recurrent optic neuritis (rON) initially seeking treatment. DESIGN: Cross-sectional cohort study. PARTICIPANTS: The study identified patients by searching the Mayo Clinic computerized central diagnostic index (January 2000-March 2017). The 246 eligible patients fulfilled the following criteria: (1) initially seeking treatment for at least 2 consecutive episodes of optic neuritis (ON) and (2) serum available for testing. METHODS: Serum was tested for aquaporin-4 IgG and MOG IgG1 using an in-house validated flow cytometric assay using live HEK293 cells transfected with M1 aquaporin-4 or full-length MOG. MAIN OUTCOMES MEASURES: Aquaporin-4 IgG and MOG IgG1 serostatus, clinical characteristics, and visual outcomes. RESULTS: Among 246 patients with rON at presentation, glial autoantibodies were detected in 32% (aquaporin-4 IgG, 19%; MOG IgG1, 13%); 186 patients had rON only and 60 patients had rON with subsequent additional inflammatory demyelinating attacks (rON-plus group). The rON-only cohort comprised the following: double seronegative (idiopathic), 110 patients (59%); MOG IgG1 positive, 27 patients (15%; 4 with chronic relapsing inflammatory optic neuropathy); multiple sclerosis (MS), 25 patients (13%); and aquaporin-4 IgG positive, 24 patients (13%). The rON-plus cohort comprised the following: aquaporin-4 IgG positive, 23 patients (38%); MS, 22 patients (37%); double seronegative, 11 patients (18%); and MOG IgG1 positive, 4 patients (7%). The annualized relapse rate for the rON-only group was 1.2 for MOG IgG1-positive patients, 0.7 for double-seronegative patients, 0.6 for aquaporin-4 IgG-positive patients, and 0.4 for MS patients (P = 0.005). The median visual acuity (VA) of patients with the worst rON-only attack at nadir were hand movements in aquaporin-4 IgG-positive patients, between counting fingers and hand movements in MOG IgG1-positive patients, 20/800 in idiopathic patients, and 20/100 in MS patients (P = 0.02). The median VA at last follow-up for affected eyes of the rON-only cohort were counting fingers for aquaporin-4 IgG-positive patients, 20/40 for idiopathic patients, 20/25 for MS patients and MOG IgG1-positive patients (P = 0.006). At 5 years after ON onset, 59% of aquaporin-4 IgG-positive patients, 22% of idiopathic patients, 12% of MOG IgG1-positive patients, and 8% of MS patients were estimated to have severe visual loss. CONCLUSIONS: Glial autoantibodies (MOG IgG1 or aquaporin-4 IgG) are found in one third of all patients with rON. Aquaporin-4 IgG seropositivity predicts a worse visual outcome than MOG IgG1 seropositivity, double seronegativity, or MS diagnosis. Myelin oligodendrocyte glycoprotein IgG1 is associated with a greater relapse rate but better visual outcomes.

Antibody drug quantitation in coexistence with anti-drug antibodies on nSMOL bioanalysis.

Therapeutic monoclonal antibodies (mAbs) are developed for treatment of diverse cancers and autoimmune diseases. For expansion of mAbs approval against unapproved diseases and pharmaceutical development, pharmacokinetics study is very important. Bioanalysis provides one of the most essential index against pharmacokinetics information. So far, we developed useful method for bioanalysis of mAbs in plasma or serum, nSMOL: nano-surface and molecular-orientation limited proteolysis. This method can provide accurate and reproducible value of mAbs content in plasma. Quantification of mAbs using ELISA is strongly influenced by endogenous ligand or anti-drug antibodies. In this report, we exhibited the role of nSMOL proteolysis coupled to LC-MS/MS analysis against quantification of mAbs bound to some binding molecules. The ligands against mAbs do not affect quantification of mAbs concentration in plasma using nSMOL proteolysis. On the other hands, some anti-drug antibodies (ADA), such as idiotypic antibodies, inhibit quantification of mAbs using nSMOL proteolysis. Acid dissociation has some efficacy in accurate value of quantitation of ADA binding mAbs using nSMOL proteolysis coupled to LC-MS/MS analysis. Accordingly, we consider that nSMOL method will contribute to understanding of mAb PK data and therapeutic reference combining with ADA measurements.

Neutropenia and monocytopenia in recurrent anaphylactoid reactions after red blood cell transfusions in a woman with immunoglobulin A (IgA) deficiency and anti-IgA.

BACKGROUND: Transfusion-associated anaphylaxis has been associated with anti-immunoglobulin A (anti-IgA) of IgG class in patients with IgA deficiency. In recent years, however, the frequency and clinical impact of this syndrome has been questioned. We present a case of recurrent red blood cell (RBC) transfusion-associated anaphylactoid reactions (rigors, hypertension, transient monocytopenia, and neutropenia) associated with anti-IgA. CASE REPORT: An 88-year-old woman developed anemia after a traumatic right humerus fracture. After receiving approximately 100 mL of RBCs she developed rigors and hypertension; her absolute neutrophil and monocyte counts decreased by 73 and 100%, respectively. All symptoms and signs resolved, and her blood counts normalized. A second RBC transfusion was given, with recurrence of rigors, hypertension, neutropenia, and monocytopenia (69 and 100% declines, respectively), along with fever. All tests for hemolysis were negative. She then received two transfusions of washed RBCs, without incident. The patient was found to be deficient in IgA (<0.05 mg/dL). Further, anti-IgA of IgG class antibodies were detected in high levels by enzyme-linked immunosorbent assay (>1000 U/mL). We reviewed case reports, case series, and reviews of IgA deficiency-associated reactions, examining whether hypertensive reactions and acute neutropenia and/or monocytopenia have been associated with anti-IgA reactions. RESULTS: Reports of reactions associated with anti-IgA emphasize hypotension and are generally classified as "anaphylactic or anaphylaxis." No previous reports described neutropenia or monocytopenia. CONCLUSION: Our case suggests that adverse transfusion reactions associated with anti-IgA of IgG class may sometimes be characterized by anaphylactoid features such as rigors and hypertension, with transient monocytopenia and neutropenia.