Anti-Ku antibodies. Study of prévalence and of clinical meaning

PURPOSE: Auto-immunity against Ku nuclear antigens is rare and clinical meaning remains badly estimated. Our study is for purposes: to appreciate the prévalence of antibodies anti-Ku within the framework of the search for antinuclear antibodies and to clarify clinical and biological relations associated to this auto-immunity. METHODS: A retrospective study of a series of 10,000 searches for antinuclear antibodies studies the prévalence of the auto-immunity anti-Ku and a retrospective analysis of the data found at the patients bearers of an anti-Ku identifies clinical and biological signs associated with this antibody. RESULTS: Prévalence anti-Ku is low (1/3493 case of antinuclear antibodies) and association is possible with in a myositic process through variable auto-immune contexts (overlap syndrome) of relative good preview. CONCLUSION: Auto-immunity anti-Ku is so characterized with its weak prévalence, a possible observation during different auto-immune diseases with an obvious frequency of the overlap syndrome often concerning a process myositic. Finally a weak évolutivité seems to characterize the auto-immune diseases of the patients with anti-Ku antibodies.     

Structure-based design of conformation- and sequence-specific antibodies against amyloid β

Conformation-specific antibodies that recognize aggregated proteins associated with several conformational disorders (e.g., Parkinson and prion diseases) are invaluable for diagnostic and therapeutic applications. However, no systematic strategy exists for generating conformation-specific antibodies that target linear sequence epitopes within misfolded proteins. Here we report a strategy for designing conformation- and sequence-specific antibodies against misfolded proteins that is inspired by the molecular interactions governing protein aggregation. We find that grafting small amyloidogenic peptides (6-10 residues) from the Aβ42 peptide associated with Alzheimer's disease into the complementarity determining regions of a domain (V(H)) antibody generates antibody variants that recognize Aβ soluble oligomers and amyloid fibrils with nanomolar affinity. We refer to these antibodies as gammabodies for grafted amyloid-motif antibodies. Gammabodies displaying the central amyloidogenic Aβ motif (18VFFA21) are reactive with Aβ fibrils, whereas those displaying the amyloidogenic C terminus (34LMVGGVVIA42) are reactive with Aβ fibrils and oligomers (and weakly reactive with Aβ monomers). Importantly, we find that the grafted motifs target the corresponding peptide segments within misfolded Aβ conformers. Aβ gammabodies fail to cross-react with other amyloidogenic proteins and scrambling their grafted sequences eliminates antibody reactivity. Finally, gammabodies that recognize Aβ soluble oligomers and fibrils also neutralize the toxicity of each Aβ conformer. We expect that our antibody design strategy is not limited to Aβ and can be used to readily generate gammabodies against other toxic misfolded proteins.     

Drug levels, anti-drug antibodies, and clinical efficacy of the anti-TNFα biologics in rheumatic diseases

The objectives of this study are to evaluate the effect of anti-drug antibodies on the clinical efficacy and withdrawal rate of the anti-TNFα biologics in patients with rheumatic diseases. Consecutive patients with rheumatic diseases recently commenced on anti-TNFα biologics were recruited. Serum samples were collected for assay of drug level and antibody titer against the corresponding biologics. Comparison of the clinical efficacy and drug retention rate was performed between patients with and without anti-drug antibodies. Fifty-eight Chinese patients were studied (64 % women; age 47.8?±?12.9 years; disease duration 6.7?±?6.4 years). The proportion of patients using infliximab (IFX), adalimumab (ADA), and etanercept (ETN) was 41, 28, and 31 %, respectively. Antibodies against IFX, ADA, and ETN were demonstrated in 12(50 %), 5(31 %) and 0(0 %) patients, respectively. Patients who developed anti-drug antibodies had significantly lower levels of the corresponding drugs (IFX level: 0.004?±?0.01 vs 3.81?±?3.49 μg/ml; p?=?0.002; ADA level: 0.0 vs 7.6?±?8.3 μg/ml; p?=?0.008). Anti-drug antibody-positive patients had a significantly higher cumulative drug withdrawal rate due to inefficacy (64.7 and 71.8 % vs 10.3 and 10.3 % at month 12 and month 24, respectively; p?<?0.001). In rheumatoid arthritis and psoriatic arthritis, non-responders was significantly more frequent in antibody-positive patients (54 vs 13 %; p?=?0.01). In spondyloarthritis, the improvement in ankylosing spondylitis disease activity score was significant in patients without antibodies (3.89?±?0.82 to 2.22?±?0.86; p?=?0.01) but not in those with anti-drug antibodies (3.40?±?1.67 to 3.23?±?1.40; p?=?0.73). We concluded that the presence of neutralizing antibodies is associated with lower serum levels of the anti-TNFα biologics, leading to lower efficacy and higher withdrawal rate.     

Measles,rubella, mumps and Toxoplasma gondii antibodies in saliva of vaccinated students of schools and universities in São Paulo City,Brazil

IntroductionVaccines are well-established public health interventions with major impact on the prevalence of infectious diseases, but outbreaks are occurring frequently due to primary and secondary failures, despite high coverage. Surveillance of efficacy and duration of induced immunity is a difficult task as it requires invasive blood sampling in children and teenagers. Saliva can be an acceptable alternative source of IgG to assess vaccine efficacy and toxoplasmosis incidence. We investigated IgG response for measles, mumps, rubella, and T. gondii in saliva samples of vaccinated young people.MethodsSaliva was collected from 249 public schools students from São Paulo, Brazil, aged 7 to 13 years old, during an interactive exhibition on hygiene. We used S. aureus protein A solid phase capture assay for IgG reactive to biotinylated purified proteins. Paired saliva and serum (47) were tested from young adults with serum evidence of T. gondii infection and from negative children less than 12 month old for standardization. Reproducibility was greater than 98% and sensitivity and specificity of the saliva assays were greater than 95%, as well as the concordance of paired saliva and serum samples.ResultsSaliva from high school students showed a prevalence of 8.5% (95% CI: 5.0–11.9%) for anti T. gondii IgG; 96.8% (94.6–99%) of anti-measles IgG; 59.1% (53–65%) of anti-rubella IgG, and 57.5% (51.3–63.6%) of anti-mumps IgG.DiscussionThe prevalence of antibodies against mumps and rubella after 6–8 years of vaccination was lower than against measles among students. The findings of this study demonstrate the feasibility of saliva sampling for follow-up of vaccine immune status in teenagers. This useful approach allows for IgG detection for vaccine control or epidemiological studies.     

Partial overlap of anti-mycobacterial, and anti- Saccharomyces cerevisiae mannan antibodies in Crohn＇s disease

AIM： To test whether humoral immune reaction against mycobacteria may play a role in anti- Saccharomyces cerevisiae antibodies （ASCA） generation in Crohn＇s disease （CD） and/or whether it correlates with clinical subtypes.
METHODS： The dominant ASCA epitope was detected by Galanthus nivalis lectin （GNL）-binding assay. ASCA and IgG against mycobacterial lysates （M avium, M smegmatis, M chelonae, M bovis BCG M avium ssp. paratuberculosis （MAP）] or purified lipoarabinomannans （LAM） were detected by ELISA. ASCA and anti-mycobacterial antibodies were affinity purified to assess cross-reactivities. Anti-mycobacterial IgG were induced by BCG-infection of mice.
RESULTS： GNL bound to different extents to mycobacterial lysates, abundantly to purified mannosecapped （Man） LAM from M tuberculosis, but not to uncapped LAM from M srnegrnatis. Fifteen to 45% of CD patients but only 0%-6% of controls were seropositive against different mycobacterial antigens. Anti-mycobacterial IgG correlated with ASCA （r = 0.37-0.64; P = 0.003-P 〈 0.001）. ASCA-positivity and deficiency for mannan-binding lectin synergistically associated with anti-mycobacterial IgG. In some patients, anti-mycobacterial antibodies represent crossreactive ASCA. Vice-versa, the predominant fraction of ASCA did not cross-react with mycobacteria. Finally, fistulizing disease associated with antibodies against M avium, M smegmatis and MAP （P = 0.024, 0.004 and 0.045, respectively）.
CONCLUSION： Similar to ASCA, seroreactivity against mycobacteria may define CD patients with complicated disease and a predisposition for immune responses against ubiquitous antigens. While in some patients anti-mycobacterial antibodies strongly cross-react with yeast mannan; these cross-reactive antibodies only represent a minor fraction of total ASCA. Thus, mycobacterial infection unlikely plays a role in ASCA induction.     

Preparation and application of monoclonal antibodies against hepatitis C virus nonstructural proteins

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Update on Anti-Saccharomyces cerevisiae antibodies, anti-nuclear associated anti-neutrophil antibodies and antibodies to exocrine pancreas detected by indirect immunofluorescence as biomarkers in chronic inflammatory bowel diseases： Results of a multicenter study

AIM: Anti-Saccharomyces cerevisiae antibodies (ASCA), anti-nuclear associated anti-neutrophil antibodies (NANA) and antibodies to exocrine pancreas (PAB), are serological tools for discriminating Crohn’s disease (CrD) and ulcerative colitis (UC). Like CrD, coeliac disease (CoD) is an inflammatory bowel disease (IBD) associated with (auto) antibodies. Performing a multicenter study we primarily aimed to determine the performance of ASCA, NANA and PAB tests for IBD diagnosis in children and adults, and secondarily to evaluate the prevalence of these markers in CoD. METHODS: Sera of 109 patients with CrD, 78 with UC, 45 with CoD and 50 healthy blood donors were retrospectively included. ASCA, NANA and PAB were detected by indirect immunofluorescence (IIF). RESULTS: ASCA /NANA- profile displayed a positive predictive value of 94.2% for CrD. Detection of ASCA was correlated with a more severe clinical profile of CrD and treatment of the disease did not influence their serum levels. ASCA positivity was found in 37.9% of active CoD.PAB were found in 36.7% CrD and 13.3% CoD patients and were not correlated with clinical features of CrD, except with an early onset of the disease. Fifteen CrD patients were ASCA negative and PAB positive. CONCLUSION: ASCA and PAB detected by IIF are specific markers for CrD although their presence does not rule out a possible active CoD. The combination of ASCA, NANA and PAB tests improves the sensitivity of immunological markers for CrD. Repeating ASCA, NANA, and PAB testing during the course of CrD has no clinical value.     

McAb-ELISA for detection of circulating antigen in schistosomiasis (I) Preparation, selection of monoclonal antibodies and preliminary test.

Fusion tests between spleen cells from BALB/c mice mfected with Schistosoma japonicum or S-mansoni cercariae with Sp2/0 myeloma were carried out.More than 30 cell lines of monoclonal anti-bodies were obtained.Their target antigens were from tegument,gut and egg respectively.The prelimi-nary tests showed that the antibody against gut-associated polysaccharide antigen was of the highestactivity.This antibody can be usec in sandwich ELISA to detect trichloroacetic acid soluble antigen in     

Sjögren's syndrome, cavitating lung disease and high sustained levels of antibodies to serine proteinase 3

A case is described involving Sj?gren's syndrome, high sustained levels of antibodies to serine proteinase 3, and cavitating lung disease. Possible diagnoses accounting for this unusual combination include a novel association of Sj?gren's syndrome and Wegener's granulomatosis (suggested by the high and sustained levels of antibodies to serine proteinase 3) or a rare presentation of bronchiolitis obliterans organising pneumonia. Identification of the true nature of the patients illness facilitated more active management and a swift resolution of the clinical problem.     

Diagnostic and prognostic significance of measuring antibodies to alpha-fodrin compared to anti-Ro-52, anti-Ro-60, and anti-La in primary Sjögren's syndrome

OBJECTIVE: To compare sensitivity and specificity of autoantibodies to alpha-fodrin with conventional anti-Ro and anti-La antibodies in patients with primary Sj?gren's syndrome (pSS). Data on internal organ manifestations were correlated with presence of autoantibodies. METHODS: We collected clinical and laboratory data from 321 patients with pSS (Copenhagen criteria), of which 205 fulfilled the new American-European 2002 consensus criteria. Sera were tested for autoantibodies against alpha-fodrin and recombinant Ro-52, Ro-60, and La proteins. RESULTS: Antibodies to alpha-fodrin were not diagnostically superior to conventional anti-Ro/La testing. IgG anti-La had the highest specificity (97%). A highly significant association was found between presence of anti-La and internal organ manifestations (OR 6, 95% CI 2.99-12.03) or hematological abnormalities. The pattern of autoantibodies was relatively independent of disease duration, indicating that these antibodies appeared early in pSS, probably even years before the first symptoms were manifest. CONCLUSION: We could not confirm that antibodies to alpha-fodrin had higher specificity or sensitivity than anti-Ro/La. Anti-La antibodies were strongly correlated to organ involvement and cytopenias, and thus could serve as a prognostic marker in pSS.     

Occurrence of antibodies against Leptospira spp. in horses of the urban area of Londrina, Paraná, Brazil

A total of 320 horses were studied in this paper, both male and female, between two and 17 years of age, which were used for traction of wagons in the urban area of the municipality of Londrina (PR). These animals were kept, after their daily work, in abandoned areas or plots, in the outskirts of the urban area of the city. When these animals were attended by the veterinarians, between 1996 and 2005, none of them presented symptoms suggesting leptospirosis. The most frequent reasons for the visit were loss of weight, unwillingness for work, parasitism, laminess, and wounds. Microscopic Seroagglutination Test (SAM), with 22 Leptospira serovars, was performed in sera sample from all these animals. The aim of this study was to investigate the occurrence of antibodies against Leptospira spp. in horses from the urban area of Londrina (PR). From the samples tested, 214 (66.88%) were considered positive, with titers between 100 and 3200, being that 49 (22.90%) presented antibodies against a single serovar of Leptospira, and 165 (77.10%) samples presented antibodies against two or more serovars simultaneously, where in 88 (53.33%) it was possible to characterize the most likely probable serovar. Antibodies against the serovar Icterohaemorrhagiae were detected in 32 (23.36%) animals.     

What is the use of biopsy and antibodies in coeliac disease diagnosis?

The advent of highly sensitive and specific serological markers has led to some protagonists proposing that coeliac disease can be diagnosed without the need for a biopsy. However, this is an area of controversy. Lack of consensus about diagnostic degrees of histological change, paucity of symptoms, antibody-negative disease and immunodeficiency can make diagnosis difficult even with a biopsy. Conversely, an argument can be put forward for a 'no biopsy' approach based on the large number of patients with typical symptoms and positive serology who experience a diagnostic delay. In addition, endoscopy is not without discomfort. This article discusses the use of antibodies and duodenal biopsy within this context. Finally, we propose a pragmatic diagnostic algorithm for clinicians to use when investigating patients for coeliac disease.     

Prevalence of human herpesvirus 8 antibodies in the population of Belém,Pará, Brazil

Serum samples from 497 children and adults inhabiting two neighbourhoods (Guamá and Terra Firme) in Belém, Pará, North Brazil were screened for the presence of human herpesvirus 8 (HHV-8) antibody using an enzyme-linked immunosorbent assay. An overall 16.3% prevalence was found for these urban communities. Taken both genders together, prevalence rates of HHV-8 antibody increase gradually, across age-groups, ranging from 12.0% to 33.3%. When seroprevalence is analysed by gender, similar rates are found for female (18.4%) and male (14.0%) individuals. In the former gender group, seroprevalence rates increased from 10.3%, in children < or = 10 years of age, to 30.0% in adults 41-50 years of age. Conversely, among male subjects, the prevalence of HHV-8 antibodies decreased from 13.3% in children/young adults aged < or = 10 to 20 years of age to 6.1% in adults aged 21-30 years. From the 31-40 year-old group male onwards, seropositivity rates increased gradually, ranging from 8.3% to 66.7%. A significant difference in seropositivity rates was noted when comparing 21-30 age groups for female and male subjects: 23.3% and 6.1%, respectively (P = 0.03). Geometric mean optical densities were found to increase slightly from the lower to the higher age-groups. Our data suggest that transmission of HHV-8 occurs frequently in the general urban population of Belém, and that prevalence of antibody seems to increase with age.     

Detection of malaria antibodies with ELISA.

The ELISA test for detecting malaria antibodies using the FCC-2 strain of Plas-modium falciparum grown in vitro and prepared on microscopic slides as an antigen wasdescribed. Serum samples obtained from 270 normal subjects and 404 Datients with P.falciparum or P. vivax infections 1-4 months before were tested.     

IgG and IgM isotypes of anti-cardiolipin and anti-β 2-glycoprotein i antibodies reflect different forms of recent thrombo-embolic events

We correlated the distribution and levels of serum anti-cardiolipin (aCL) and anti-₂-glycoprotein-1 antibodies (anti-₂-GPI) of the IgG and IgM isotypes to the clinical spectrum of recent (<6 months) thrombo-embolic events in a cohort of 162 patients. Clinical information was obtained by questionnaires from the referring physicians. Cerebro-vascular infarction (CVI) had taken place in 82 patients, deep venous thrombosis (DVT) in 34, pulmonary embolism (PE) in 14, myocardial infarction (MI) in four, and other thromboses in 28 patients. SLE was the most commonly associated rheumatic disease and accounted for 20 (12%) patients. In 124 (77%) patients no underlying rheumatic disease was identified. Isolated IgG aCL was found in 31 of 48 patients with DVT/PE (65%), but in only 21 of 82 patients with CVI (26%); p<0.0001. IgG anti-₂-GPI were detected in 23 (48%) DVT/PE patients, but in only 13 (16%) CVI patients; p<0.001. The IgG class anti-₂-GPI positive patients had significantly higher levels of IgG aCL (mean 65 units) compared to IgG anti-₂-GPI negative patients (mean 29 units); p<0.0001. In contrast, isolated IgM aCL was found in nine (19%) patients with DVT/PE, but in 46 (56%) CVI patients; p<0.0001. Only ten patients had IgM anti-₂-GPI. The present study shows that the IgG and IgM aCL isotypes seem to define different clinical subsets of patients with thrombo-embolic events with IgG aCL being most prevalent in the group having DVT/PE, IgM aCL being found primarily among CVI patients.     

Apoptotic and antitumor activity of death receptor antibodies require inhibitory Fcγ receptor engagement

By virtue of their ability to induce apoptosis and regulate growth, differentiation, and cytokine responses, the tumor necrosis factor receptor (TNFR) superfamily members have emerged as attractive targets for anticancer therapeutics. Agonistic antibodies to apoptosis-inducing TNFRs, such as death receptor 5 (DR5), although displaying impressive activities against a variety of tumors in preclinical models, appear to be less active in clinical trials. We report that the in vivo apoptotic and antitumor activities of these antibodies have an absolute requirement for the coengagement of an inhibitory Fcγ receptor, FcγRIIB. Anti-DR5 antibodies of the type currently in clinical trials have weak FcγRIIB binding and thus are compromised in their proapoptotic and antitumor activities in both colon and breast carcinoma models. Enhancing FcγRIIB engagement increases apoptotic and antitumor potency. Our results demonstrate that Fc domain interactions are critical to the therapeutic activity of anti-DR5 antibodies and, together with previous reports on agonistic anti-CD40 antibodies, establish a common requirement for FcγRIIB coengagement for optimal biological effects of agonistic anti-TNFR antibodies.