Detection Of Antibodies In Patients Research Articles

#2402 Reproducibility of memory B-cell and HLA antibody detection in patients on kidney transplant waiting list

Abstract Background and Aims Detection of HLA antibodies (HLA-Abs) impacts on the access and outcomes of kidney transplantation (KT). Currently, evaluation of HLA-Abs in serum is performed using single antigen bead assays (SAB). The analysis of circulating HLA-specific memory B cells (mBc), capable of differentiating to HLA-Abs secreting cells, was conceived with the aim of complementing the study of the HLA-Abs found in serum, but there is debate regarding the representativeness and reproducibility of the test. Thus, we studied HLA-Abs generated by mBc from patients on the waiting list (WL) at two different time points without sensitizing events in between and compared them with HLA-Abs detected in serum. Method We selected 7 patients on the WL for a first KT with a cPRA of 3%-100%: 4 had pregnancies and 2 had blood transfusions as known sensitizing events. We collected blood and serum samples at 2 time points separated by an average of 3.5 months (T1, T2). We cultured polyclonally activated PBMCs and isolated and concentrated IgG from the supernatant (SN) to study HLA-Abs. We tested SN and sera with SAB assays. Beads with MFI >750 were considered positive. Results SAB serum study (Fig. 1a). Eighty-two percent of the specificities found at T1 were also detected at T2, and 97% of those identified at T2 were also observed at T1. Thus, there was good concordance between T1 and T2 samples (κ = 0.869, Cohen) and the MFI the specificities correlated (p < 0.0001, Spearman). SAB SN study (Fig. 1b). Forty-one percent of the positive specificities detected at T1 were also identified at T2, and 59% of the positive specificities found at T2 had been seen at T1. Thus, there was a moderate concordance between T1 and T2 samples (κ = 0.454, Cohen) and the MFI of the specificities still correlated (p < 0.0001, Spearman). Only 42% and 35% of the positivities found in serum were also detected in the SN at T1 and T2, respectively. However, we found 9 positivities unique to the SN T1 (100% HLA-ABC) in 2 patients with cPRA>80% and we also identified a total of 20 positivities unique to the SN at T2 (45% HLA-ABC, 55% HLA-DPDQDR) in 3 patients with cPRA>80%. Conclusion The study of the degree of sensitization with SAB serum analysis remains stable between samples along time, while the mBc analysis shows less reproducibility. We identified a higher number of HLA-Ab in the study of serum compared with the study of the SN of mBc; however, we found some HLA-Abs unique to the SN. We suggest that, probably due to the small number of circulating mBC, increasing the number of samples tested for mBc improves the representativeness of the test.

Histoplasma capsulatum Complement Fixation and Immunodiffusion Assay Sensitivity in Culture-Confirmed Cases of Histoplasmosis: a 10-Year Retrospective Review (2011 to 2020).

The detection of antibodies against Histoplasma capsulatum remains a frequently relied-on approach to diagnose histoplasmosis. We retrospectively assessed the performances of complement fixation (CF) and immunodiffusion (ID) assays for anti-Histoplasma antibody detection in patients with culture-confirmed histoplasmosis at Mayo Clinic (Rochester, MN) over a 10-year period (2011 to 2020). Among 67 culture-confirmed patients who also had H. capsulatum CF/ID testing ordered, 51 (67.1%) were immunocompromised, 34 (50.7%) had localized disease, and 51 (76.1%) presented with <3 months of symptoms before testing. H. capsulatum CF and/or ID testing was positive in 47 (70.1%) patients, with both assays being positive in 39 cases. CF was positive in 44 (65.7%) patients, with reactivity against both H. capsulatum mycelial and yeast antigens in 30 (68.2%) cases, whereas 11 (25%) and 3 (6.8%) individuals had antibodies to the CF yeast or mycelial antigen only, respectively. H. capsulatum ID was positive in 42 (62.7%) patients, with the presence of the M-band only or the H- and M-bands in 27 (64.3%) and 15 (35.7%) cases, respectively. Among 18 serially tested patients, 12 remained ID and/or CF positive at the final time point (median, 154 days; range, 20 to 480 days). Serial CF testing showed that antibodies to the mycelial antigen serorevert to negative more frequently (6/11) than antibodies to the yeast antigen (2/13). There was no statistically significant difference in antibody positivity relative to patient immune status, degree of disease dissemination, or symptom duration. Serologic testing remains a valuable asset to support the diagnosis of histoplasmosis, particularly when direct detection methods fail to identify an infection.

Detection of Antibodies in Patients with COVID-19 by Rapid Chromatographic Immunoassay

Detection of Antibodies in Patients with COVID-19 by Rapid Chromatographic Immunoassay

Clinical significance of early IgA anti-SARS-CoV-2 antibody detection in patients from a Romanian referral COVID-19 hospital.

Controlling the spread of coronavirus disease 2019 (COVID-19) includes institute isolation, quarantine measures and appropriate clinical management, which all require effective screening, diagnostic and prognostic tools. The present study aimed to analyze severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific immunoglobulin (Ig)A detection and determine the potential association with the clinical course of COVID-19 and the levels of inflammation. In the present study, the presence of IgA and IgG SARS-CoV-2 antibodies in 75 consecutive patients with confirmed COVID-19 infection was investigated. No significant differences were found between the IgA positive and negative groups, regarding the presence of symptoms, haematological and inflammatory variables, or the presence of pneumonia. In the majority of cases, antibody detection was comparable, for example, 79.7% of patients in the IgA positive group exhibited both types of antibodies, while 80.9% of patients in the IgA negative group were also IgG negative. A total of four patients in the IgA negative group presented with anti-SARS-CoV-2 IgG antibodies. Early detection of IgA was more frequent in patients who later developed severe forms of the disease. In addition, the IgG SARS-CoV-2 antibody response was higher in patients with the severe form of the disease.

Sensitive Detection of Antibodies in Patients with Acute Coxiella Burnetii Infection

Sensitive Detection of Antibodies in Patients with Acute Coxiella Burnetii Infection

Detection of Anti-Erythropoietin Antibodies in Patients with Chronic Renal Failure Undergoing Hemodialysis

Background: Erythropoietin, a hormone produced by the kidney, activates the bone marrow upon demand. Recombinant erythropoietin can be subcutaneously injected to maintain red blood cell counts in chronic renal failure patients. Some time being recognized as foreign antigens, the patient occasionally produces antibodies against erythropoietin. Objective of current study was to investigate the existence of Anti-Erythropoietin Antibodies in Chronic Renal Failure (CRF) affected individuals during hemodialysis. Methods: The current study was performed at the Pathology Department, Khyber Teaching Hospital, Peshawar, Pakistan. After the assent of ethical committee, data collection was initiated to carry out the study. All the patients filled the informed consent proforma. The blood sample was collected in two EDTA and Gel tubes for complete blood count and for anti-EPO-antibodies respectively. ELISA tests for anti-EPO antibodies were performed on all patients who were classified into two groups based on whether antibodies were present or not. The data was analyzed using SPSS version 25.0. Results: In this study, 150 patients suffering from Chronic Kidney Disease on dialysis were included in which 79 (52.7%) were males. Moreover, age-wise group 41-60 years (n=93, 62%) were more suffering as compared to age group 21-40 years (n=24, 16%). In our study, hypertension was found to be a leading cause of death for 65(43.3%), diabetes 32(21.3%), hypertension and diabetes mellitus 10(6.7%), and miscellaneous accounted for 28.7%. There were 56(37.3%) patients who received dialysis twice a week, and 94 patients (62.6%) received it three times a week. Patients had transfusion history were 136(90.7%), while 92 (61.3%) patients were found to have anti-EPO antibodies. Conclusion: Anti-EPO antibodies are frequently demonstrated in patients with CKD undergoing hemodialysis. Due to the lack of correlation between antibody levels and Hb or reticulocyte counts, these antibodies might not be neutralizing antibodies. Keywords: Anti-EPO antibodies, Chronic Renal Failure, Hypertension, Peshawar.

High-specificity targets in SARS-CoV-2 N protein for serological detection and distinction from SARS-CoV

Numerous serological detection kits are being rapidly developed and approved for screening and diagnosing suspected coronavirus disease 2019 (COVID-19) cases. However, cross-reactivity between pre-existing antibodies against other coronaviruses and the captured antigens in these kits can affect detection accuracy, emphasizing the necessity for identifying highly specific antigen fragments for antibody detection. Thus, we performed a conservation and specificity analysis of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) protein. We also integrated various B-cell epitope prediction methods to obtain possible dominant epitope regions for the N protein, analyzed the differences in serological antibody levels for different epitopes using ELISA, and identified N protein epitopes for IgG and IgM with high-specificity. The SARS-CoV-2 N protein showed low mutation rates and shared the highest amino acid similarity with SARS-CoV; however, it differed substantially from other coronaviruses. Tests targeting the SARS-CoV-2 N protein produce strong positive results in patients recovering from SARS-CoV. The N18–39 and N183-197 epitopes for IgG and IgM detection, respectively, can effectively overcome cross-reactivity, and even exhibit good specificity between SARS-CoV-2 and SARS-CoV. The antibody levels detected with these were consistent with those detected using the complete N protein. These findings provide a basis for serological diagnosis and determining the kinetics of SARS-CoV-2 antibody detection in patients.

Comparing Immunoassays for SARS-CoV-2 Antibody Detection in Patients with and without Laboratory-Confirmed SARS-CoV-2 Infection.

ABSTRACTCommercially available SARS-CoV-2-directed antibody assays may assist in diagnosing past exposure to SARS-CoV-2 antigens. We cross-compared the following eight immunoassays detecting antibodies against SARS-CoV-2 nucleocapsid (N) or spike (S) antigens in three cohorts consisting of 859 samples from 622 patients: (#1) EDI novel coronavirus COVID-19 (Epitope), (#2) RecomWell SARS-CoV-2 (Mikrogen), (#3) COVID-19 ELISA (VirCell), (#4) Elecsys anti-SARS-CoV-2 N (Roche), (#5) Liaison SARS-CoV-2 S1/S2 (DiaSorin), (#6) anti-SARS-CoV-2 ELISA (EuroImmun), (#7) Elecsys anti-SARS-CoV-2 S (Roche), and (#8) Liaison SARS-CoV-2 TrimericS (DiaSorin). In cross-sectional cohort 1 (68 sera from 38 patients with documented SARS-CoV-2 infection), agreement between assays #1 to #6 ranged from 75% to 93%, whereby discordance mostly resulted from N-based assays #1 to #4. In cross-sectional cohort 2 (510 sera from 510 patients; 56 documented, 454 unknown SARS-CoV-2 infection), assays #4 to #6 were analyzed further together with assays #7 and #8, revealing 94% concordance (44 [9%] positives and 485 [85%] negatives). Discordance was highest within 2 weeks after SARS-CoV-2/COVID-19 diagnosis and confirmed in the longitudinal cohort 3 (281 sera from 74 COVID-19 patients), using assays #4, #6, #7, and #8. Subanalysis of 20 (27%) initially seronegative cohort 3 patients revealed assay-dependent 50% and 90% seroconversion rates after 8 to 11 days and 14 to 18 days, respectively. Increasing SARS-CoV-2 antibodies were significantly associated with declining levels of viral loads, lactate dehydrogenase, interleukin-6, and C-reactive protein and preceded clearance of SARS-CoV-2 detection in the upper respiratory tract by approximately 1 week. SARS-CoV-2-specific antibody assays show substantial agreement, but interpretation of qualitative and semiquantitative results depends on the time elapsed postdiagnosis and the choice of viral antigen. Mounting of systemic SARS-CoV-2-specific antibodies may predict recovery from viral injury and clearance of mucosal replication.

Comparison of commercial lateral flow immunoassays and ELISA for SARS-CoV-2 antibody detection

COVID-19 pandemic has spread worldwide since December 2019. Serological tests for SARS-CoV-2 antibody testing are needed for detection of current or past infections. A wide range of commercial tests is available. However, most of them need to be validated. The aim was to compare a commercial IgG and IgA ELISA (Euroimmun) with three lateral flow immunoassays (LFI): Hangzhou Alltest Biotech, Wuhan UNscience Biotechnology and Guangzhou Wondfo Biotech. Specificity was calculated with 62 available serum samples from 2018/19. The study included 152 sera from patients of which 109 were RT-PCR positive. Sensitivities for ELISA anti SARS-CoV-2 IgG and IgA were 81.5 % and 93.1 % and specificities 100 % and 80.6 %, respectively. LFI showed variable performances, overall results being better for Guangzhou Wondfo Biotech. Commercial serological tests are useful for detection of antibodies in patients with COVID-19. ELISA presented better results than LFI. The results allowed to incorporate the most sensitive LFI to the daily workflow, combining with ELISA. Careful validation is encouraged before clinical laboratories start using these tests.

Analysis of adjunctive serological detection to nucleic acid test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnosis

BackgroundThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused coronavirus disease 2019 (COVID-19) epidemic in China, December 2019. The clinical features and treatment of COVID-19 patients remain largely elusive. However, accurate detection is required for SARS-CoV-2 infection diagnosis. We aimed to evaluate the antibodies-based test and nucleic acid-based test for SARS-CoV-2-infected patients. MethodsWe retrospectively studied 133 patients diagnosed with SARS-CoV-2 and admitted to Renmin Hospital of Wuhan University, China, from January 23 to March 1, 2020. Demographic data, clinical records, laboratory tests, and outcomes were collected. Data were accessed by SARS-CoV-2 IgM-IgG antibody test and real-time reverse transcriptase PCR (RT-PCR) detection for SARS-CoV-2 nucleic acid in COVID-19 patients. ResultsOf 133 COVID-19 patients, there were 44 moderate cases, 52 severe cases, and 37 critical cases with no differences in gender and age among three subgroups. In RT-PCR detection, the positive rate was 65.9%, 71.2%, and 67.6% in moderate, severe, and critical cases, respectively. Whereas the positive rate of IgM/IgG antibody detection in patients was 79.5%/93.2%, 82.7%/100%, and 73.0%/97.3% in moderate, severe, and critical cases, respectively. Moreover, the IgM and IgG antibodies concentrations were also examined with no differences among three subgroups. ConclusionThe IgM-IgG antibody test exhibited a useful adjunct to RT-PCR detection, and improved the accuracy in COVID-19 diagnosis regardless of the severity of illness, which provides an effective complement to the false-negative results from a nucleic acid test for SARS-CoV-2 infection diagnosis after onsets.

The Use of Fluoroproline in MUC1 Antigen Enables Efficient Detection of Antibodies in Patients with Prostate Cancer.

A structure-based design of a new generation of tumor-associated glycopeptides with improved affinity against two anti-MUC1 antibodies is described. These unique antigens feature a fluorinated proline residue, such as a (4S)-4-fluoro-l-proline or 4,4-difluoro-l-proline, at the most immunogenic domain. Binding assays using biolayer interferometry reveal 3-fold to 10-fold affinity improvement with respect to the natural (glyco)peptides. According to X-ray crystallography and MD simulations, the fluorinated residues stabilize the antigen-antibody complex by enhancing key CH/π interactions. Interestingly, a notable improvement in detection of cancer-associated anti-MUC1 antibodies from serum of patients with prostate cancer is achieved with the non-natural antigens, which proves that these derivatives can be considered better diagnostic tools than the natural antigen for prostate cancer.

Detection of LGI1 and CASPR2 antibodies with a commercial cell-based assay in patients with very high VGKC-complex antibody levels

BackgroundThe presence of VGKC-complex antibodies, without LGI1/CASPR2 antibodies, as a standalone marker for neurological autoimmunity remains controversial. Additionally, the lack of an unequivocal VGKC-complex antibody cut-off level defining neurological autoimmunity makes it important to test for monospecific antibodies. We aim to determine the performance characteristics of a commercial assay (Euroimmun, Lübeck, Germany) for LGI1/CASPR2 antibody detection in patients with very high VGKC-complex antibody levels and report their clinico-serological associations. MethodsWe identified 8 patients in our cohort with the highest VGKC-complex antibody levels (median 2663.5pM, range 933–6730pM) with VGKC-complex antibody related syndromes (Group A). Two other groups were identified; 1 group with suspected neuronal surface antibody syndromes and negative for VGKC-complex antibodies (Group B, n=8), and another group with cerebellar ataxia and negative for onconeuronal antibodies (Group C, n=8). ResultsSeven out of 8 patients (87.5%) in Group A had LGI1 and/or CASPR2 antibodies. One Group B patient had LGI1 antibodies but was negative on re-testing with a live cell assay. No Group C patients had monospecific antibodies. Inter-rater reliability was high; combining Groups A and B patients, the kappa statistic was 0.87 and 1.0 for LGI1 and CASPR2 antibodies respectively. ConclusionWe demonstrated that a high proportion of patients with very high VGKC-complex antibody levels and relevant clinical syndromes have LGI1 and/or CASPR2 antibodies detected by the commercial assay. Our findings lend support to the use of the assay for rapid and reliable detection of LGI1 and CASPR2 antibodies.

Western Blot diagnostic yield for simultaneous antibody-detection in patients with human cysticercosis, hydatidosis, and human fascioliasis

. To determine the diagnostic yield using western blotting to simultaneously detect antibodies in patients with human cysticercosis, hydatidosis, and human fascioliasis. Materials and methods . Cross-sectional study of diagnostic yield assessment. Excretory/secretory antigens were obtained from Taenia solium larvae, Echinococcus granulosus cysts, and the adult flukes of Fasciola hepática, which were then separated using the polyacrylamide gel electrophoresis technique, transferred, and attached to a nitrocellulose membrane to be probed with sera from the patient infected with the three parasites. The sensitivity of the technique was assessed using 300 individual serum samples, 60 pools of two parasites, and 20 pools of three parasites with 75 sera from patients with other parasites, 10 from patients with other diseases, and 15 from patients without parasites. Results . The technique revealed 13 glycoproteins (GP): GP 35, 31, 24, 23, 18, 17, 14, and 13 kDa for cysticercosis; GP 8, 16, and 21 kDa for hydatidosis; and GP 17 and 23 kDa for fascioliasis. The test detected the presence of antibodies with a sensitivity of 96% (95% confidence interval [CI] = 94.62-98.54%) in the detection of one or the thirteen bands, a specificity of 100% (95% CI = 99.50-100.00%); individually, there was a sensitivity for cysticercosis of 97% (95% CI = 93.16-100.00%), for hydatidosis of 94% (95% CI = 88.85-99.15%) and for fascioliasis of 96% (95% CI = 91.66-100.00%). Conclusions . Western blotting is effective in the simultaneous detection of antibodies in patients with human cysticercosis, hydatidosis, and fascioliasis, and it can be used as a diagnostic test to either rule out or confirm the presence of antibodies in endemic areas.

Novel Phospholipid-Protein Conjugates Allow Improved Detection of Antibodies in Patients with Autoimmune Diseases.

Reliable measurement of clinically relevant autoimmune antibodies toward phospholipid-protein conjugates is highly desirable in research and clinical assays. To date, the development in this field has been limited to the use of natural heterogeneous antigens. However, this approach does not take structural features of biologically active antigens into account and leads to low reliability and poor scientific test value. Here we describe novel phospholipid-protein conjugates for specific detection of human autoimmune antibodies. Our synthetic approach includes mild oxidation of synthetic phospholipid cardiolipin, and as the last step, coupling of the product with azide-containing linker and copper-catalyzed click chemistry with β2-glycoprotein I and prothrombin. To prove utility of the product antigens, we used enzyme-linked immunosorbent assay and three cohorts of samples obtained from patients in Denmark (n = 34) and the USA (n = 27 and n = 14). Afterwards we analyzed correlation of the obtained autoantibody titers with clinical parameters for each patient. Our results prove that using novel antigens clinically relevant autoantibodies can be detected with high repeatability, sensitivity and specificity. Unlike previously used antigens the obtained autoantibody titers strongly correlate with high disease activity and in particular, with arthritis, renal involvement, anti-Smith antibodies and high lymphocyte count. Importantly, chemical composition of antigens has a strong influence on the correlation of detected autoantibodies with disease activity and manifestations. This confirms the crucial importance of antigens’ composition on research and diagnostic assays, and opens up exciting perspectives for synthetic antigens in future studies of autoimmunity.

Specific K39 antibody response and its persistence after treatment in patients with imported leishmaniasis

The sensitivity of a K39 ELISA (Leishmania IgG, Virion/Serion) for the detection of antibodies in patients with imported leishmaniasis was compared with an immunofluorescence assay (IFA), which was applied as “golden standard”. The retrospective study comprised 93 IFA-positive or borderline sera from 42 patients with visceral (n = 16) or cutaneous (n = 26) leishmaniasis. Patients had acquired infection predominately in the Mediterranean area or the Middle East. The Leishmania species (Leishmania donovani/infantum, Leishmania tropica, Leishmania major) were identified by real-time PCR. The majority (94 %) of first samples from patients with visceral leishmaniasis (VL) tested positive by K39 ELISA. Antibody levels ranged from low to very high (33.19–1990.00 U/ml; median 596.66 U/ml) but did not correlate with the respective IFA titers. High K39 ELISA values correlated with acute infection in immunocompetent individuals. K39 antibodies declined in all individuals after clinically successful therapy, but time to seronegativity varied considerably (51 weeks to >6 years). In patients with cutaneous leishmaniasis (CL), the sensitivity of the K39 ELISA was low (23 %) compared to IFA (92 % positive). Antibody levels ranged from low to medium (10.85–524.77 U/ml; median 19.77 U/ml). The highest antibody concentrations were seen in L. infantum-infected individuals. Summarizing, a high K39 ELISA value indicates active VL. The assay is, like IFA, not a measure for effective therapy but may support post-treatment monitoring. Low level positivity can indicate subclinical, previous or clinically cured VL or even CL. The K39 ELISA can supplement highly sensitive screening tests in the diagnosis and follow-up of imported leishmaniasis.

Emphysematous Cholecystitis: A Rare Complication of Hepatitis A Virus Infection

Hepatitis A virus (HAV) causes an acute hepatitis associated with significant elevatation in liver enzymes. The liver is main target of HAV and extrahepatic manifestations are scarce. The diagnosis of acute HAV infection is made by the detection of anti-HAV IgM antibody in patients with the typical clinical presentation.. Here in, we present a 22-year old male presented with malaise, fever, nause, and intensive stomach ache. In physical examination, the patient had fever, jaundice, and hepatomegaly. Laboratory tests resulted in elevated liver enzymes. Abdominal ultrasonography demonstrated thickening of the gallbladder wall, and intramural air. As the patient’s symptoms failed to regress in follow up laparoscopic cholecystectomy was performed. To sum up, HAV infection can be seen in all age groups, in developing countries, such as our country. It must be kept in mind that, although very rarely, HAV infections may exhibit extrahepatic complications.

Purification and characterization of a mycelial catalase from Scedosporium boydii, a useful tool for specific antibody detection in patients with cystic fibrosis.

Scedosporium boydii is an opportunistic filamentous fungus which may be responsible for a wide variety of infections in immunocompetent and immunocompromised individuals. This fungus belongs to the Scedosporium apiospermum species complex, which usually ranks second among the filamentous fungi colonizing the airways of patients with cystic fibrosis (CF) and may lead to allergic bronchopulmonary mycoses, sensitization, or respiratory infections. Upon microbial infection, host phagocytic cells release reactive oxygen species (ROS), such as hydrogen peroxide, as part of the antimicrobial response. Catalases are known to protect pathogens against ROS by detoxification of the hydrogen peroxide. Here, we investigated the catalase equipment of Scedosporium boydii, one of the major pathogenic species in the S. apiospermum species complex. Three catalases were identified, and the mycelial catalase A1 was purified to homogeneity by a three-step chromatographic process. This enzyme is a monofunctional tetrameric protein of 460 kDa, consisting of four 82-kDa glycosylated subunits. The potential usefulness of this enzyme in serodiagnosis of S. apiospermum infections was then investigated by an enzyme-linked immunosorbent assay (ELISA), using 64 serum samples from CF patients. Whatever the species involved in the S. apiospermum complex, sera from infected patients were clearly differentiated from sera from patients with an Aspergillus fumigatus infection or those from CF patients without clinical and biological signs of a fungal infection and without any fungus recovered from sputum samples. These results suggest that catalase A1 is a good candidate for the development of an immunoassay for serodiagnosis of infections caused by the S. apiospermum complex in patients with CF.

Serum p53 antibody detection in patients with impaired lung function

BackgroundTP53 gene mutations can lead to the expression of a dysfunctional protein that in turn may enable genetically unstable cells to survive and change into malignant cells. Mutant p53 accumulates early in cells and can precociously induce circulating anti-p53 antibodies (p53Abs); in fact, p53 overexpression has been observed in pre-neoplastic lesions, such as bronchial dysplasia, and p53Abs have been found in patients with Chronic Obstructive Pulmonary Disease, before the diagnosis of lung and other tobacco-related tumors.MethodsA large prospective study was carried out, enrolling non-smokers, ex-smokers and smokers with or without the impairment of lung function, to analyze the incidence of serum p53Abs and the correlation with clinicopathologic features, in particular smoking habits and impairment of lung function, in order to investigate their possible role as early markers of the onset of lung cancer or other cancers. The p53Ab levels were evaluated by a specific ELISA in 675 subjects.ResultsData showed that significant levels of serum p53Abs were present in 35 subjects (5.2%); no difference was observed in the presence of p53Abs with regard to age and gender, while p53Abs correlated with the number of cigarettes smoked per day and packs-year. Furthermore, serum p53Abs were associated with the worst lung function impairment. The median p53Ab level in positive subjects was 3.5 units/ml (range 1.2 to 65.3 units/ml). Only fifteen positive subjects participated in the follow-up, again resulting positive for serum p53Abs, and no evidence of cancer was found in these patients.ConclusionThe presence of serum p53Abs was found to be associated with smoking level and lung function impairment, both risk factors of cancer development. However, in our study we have not observed the occurrence of lung cancer or other cancers in the follow-up of positive subjects, therefore we cannot directly correlate the presence of serum p53Abs with cancer risk.

P551 Detection of anti infliximab antibodies in patients with inflammatory bowel disease (IBD) in the presence of infliximab by homogeneous liquid phase anti infliximab mobility shift assay

P551 Detection of anti infliximab antibodies in patients with inflammatory bowel disease (IBD) in the presence of infliximab by homogeneous liquid phase anti infliximab mobility shift assay

Clinical significance of detection of anti-neutrophil cytoplasmic antibodies in patients with autoimmune hepatitis

Clinical significance of detection of anti-neutrophil cytoplasmic antibodies in patients with autoimmune hepatitis