Antibodies In Sera Of Patients Research Articles

МОНОКЛОНАЛЬНЫЕ АНТИТЕЛА ПРОТИВ Mycobacterium avium В ИССЛЕДОВАНИИ МИКОБАКТЕРИОЗА ЛЕГКИХ

We used hybridoma technology to obtain 15 monoclonal antibodies (mAbs) to antigens of whole-cell suspension of M. avium. The isotypes and specificity of mAbs to mycobacterial and bacterial antigens were characterized. The chemical nature of the antigens/antigenic determinant recognized by the mAbs under treatment with proteinase K and metaperiodate Na and using extracted with ethanol and benzene M. avium suspension was investigated. All mAbs were purified by affinity chromatography and used in heterologous indirect two-site ELISA to determine diagnostic properties in the study of IgG antibodies in sera of patients with pulmonary tuberculosis, pulmonary mycobacteriosis or healthy donors. The presented method makes it possible to individually identify and take into account non-specific “natural” IgG antibodies of each serum under study (patent for invention No. 2794855). mAbs 1B11 showed diagnostic specificity in the detection of mycobacteriosis − 62.47% and sensitivity – 74.78%, 3E12 (anti-54kDa) − 88.89% and 52.63%, and 1H7G6 − 66.81% and 83.80%, respectively.

A cell-based, SARS-CoV-2 spike protein interaction assay to inform the neutralising capacity of recombinant and patient sera antibodies

IntroductionThe engagement of the SARS-CoV-2 spike protein with ACE2 is a critical step for viral entry to human cells, and, therefore, blocking this interaction is a major determinant of the efficacy of monoclonal antibody therapeutics and vaccine elicited serum antibodies. The emergence of SARS-CoV-2 variants has necessitated the development of adaptable assays that can be applied to assess the effectiveness of antibody-based therapeutics.MethodsThrough the testing of a range of recombinant spike proteins, we have developed a cell-based, ACE2/spike protein interaction assay that characterises monoclonal anti-spike protein antibodies and neutralising antibodies in donor serum. The assay uses high-content imaging to quantify cell-bound spike protein fluorescence.ResultsUsing spike proteins from the original “Wuhan” SARS-CoV-2 strain and the Delta and Omicron variants, we identified differential blocking activity of three monoclonal antibodies directed against the spike receptor-binding domain. Importantly, biological activity in the spike interaction assay translated to efficacy in a SARS-CoV-2 infection assay.DiscussionThe spike protein interaction assay can be used to monitor anti-spike antibodies against the major known SARS-CoV-2 variants and is readily adaptable for quantification of the impact of antibodies against new and emerging SARS-CoV-2 variants.

Simultaneous detection of antibody responses to multiple SARS-CoV-2 antigens by a Western blot serological assay.

The nucleic acid test is still the standard assessment for the diagnosis of coronavirus disease 2019 (COVID-19), which is caused by human infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In addition to supporting the confirmation of disease cases, serological assays are used for the analysis of antibody status and epidemiological surveys. In this study, a single Western blot strip (WBS) coated with multiple Escherichia coli (E. coli)-expressed SARS-CoV-2 antigens was developed for comprehensive studies of antibody profiles in COVID-19 patient sera. The levels of specific antibodies directed to SARS-CoV-2 spike (S), S2, and nucleocapsid (N) proteins were gradually increased with the same tendency as the disease progressed after hospitalization. The signal readouts of S, S2, and N revealed by the multi-antigen-coated WBS (mWBS)-based serological assay (mWBS assay) also demonstrated a positive correlation with the SARS-CoV-2 neutralizing potency of the sera measured by the plaque reduction neutralization test (PRNT) assays. Surprisingly, the detection signals against the unstructured receptor-binding domain (RBD) purified from E. coli inclusion bodies were not observed, although the COVID-19 patient sera exhibited strong neutralizing potency in the PRNT assays, suggesting that the RBD-specific antibodies in patient sera mostly recognize the conformational epitopes. Furthermore, the mWBS assay identified a unique and major antigenic epitope at the residues 1148, 1149, 1152, 1155, and 1156 located within the 1127-1167 fragment of the S2 subunit, which was specifically recognized by the COVID-19 patient serum. The mWBS assay can be finished within 14-16min by using the automatic platform of Western blotting by thin-film direct coating with suction (TDCS WB). Collectively, the mWBS assay can be applied for the analysis of antibody responses, prediction of the protective antibody status, and identification of the specific epitope. KEY POINTS: • A Western blot strip (WBS) coated with multiple SARS-CoV-2 antigens was developed for the serological assay. • The multi-antigen-coated WBS (mWBS) can be utilized for the simultaneous detection of antibody responses to multiple SARS-CoV-2 antigens. • The mWBS-based serological assay (mWBS assay) identified a unique epitope recognized by the COVID-19 patient serum.

Rapid assessment of Opisthorchis viverrini IgG antibody in serum: A potential diagnostic biomarker to predict risk of cholangiocarcinoma in regions endemic for opisthorchiasis

BackgroundOpisthorchiasis is caused by an infection with fish-borne liver flukes of the genus Opisthorchis. Opisthorchiasis frequently leads to chronic inflammation in the biliary tract and is classified as a group 1 biological carcinogen by the International Agency for Research on Cancer: a definitive risk for cholangiocarcinoma (CCA). MethodsWe used the rapid immunochromatographic test (ICT) to detect anti-Opisthorchis viverrini IgG and IgG4 subclass antibodies in sera of patients with CCA. The ICT kits were developed based on soluble antigens excreted and secreted by O. viverrini adult worms. ResultsICT indicated sera was positive for IgG and IgG4 antibodies, respectively, in 22 (61.1%) and 15 (41.6%) participants of the 36 study participants diagnosed with CCA (P > 0.05). Our study also included groups with other cancers and with liver cirrhosis, where the IgG ICT and IgG4 ICT kits were 27.7% (13/47) and 25.5% (12/47) positive, respectively (P > 0.05). Neither total the IgG ICT nor the IgG4 ICT yielded positive results in a control group of 20 healthy participants. Moreover, the percentage positivity rate using the ICT for total IgG between the CCA group and the other cancers and liver cirrhosis group was significantly different (P < 0.05). By contrast, no significant difference between these groups was apparent in the ICT for IgG4 antibody. The CCA group was 6.53 times more likely to have positive anti–O. viverrini IgG antibody (odds ratio 6.53, P < 0.001) and 3.27 times more likely to have positive anti–O. viverrini IgG4 antibody (odds ratio 3.27, P = 0.010) than the non-CCA group. ConclusionThis information is of potential value for the development of a diagnostic biomarker to predict risk for O. viverrini infection-associated CCA.

ENZYME-LINKED IMMUNOSORBENT ASSAY DETECTION FOR MALIGNANCY USING ANTI-P53 ANTIBODIES

Tumour protein 53 (p53) plays an important role in the instruction of the cell cycle. In a variety of transformed cell lines, tumour protein is expressed in high amounts, and it is believed to contribute to transformation and malignancy. This research aimed to detect the anti-p53 antibodies in sera of patients with various malignant tumours and to evaluate the sensitivity and specificity of an enzyme-linked immunosorbent assay (ELISA). A case-control study was conducted on samples from 49 patients with various types of malignant tumours at Sultanah Bahiyah Hospital, Alor Setar, Kedah, Malaysia, and 32 healthy control cases with non‐malignant disease collected from Universiti Sains Malaysia clinic, Penang, Malaysia. The antibodies against p53 protein in the serum samples were analysed using the commercial ELISA kit, Calbiochem® p53- ELISAPLUS. The results showed that the rate of anti-p53 antibodies in patients with various malignant tumours was 13 out of 49 (26.5 %), compared with only 2 out of 32 (6.25%) in healthy controls (p &lt; 0.001). The sensitivity of this kit reached 28.6% and the specificity was 93.8%. In conclusion, these results suggest that the anti-p53 antibodies can be detected in different sera of malignant tumour patients and the ELISA kit is highly specific; nevertheless, its discrimination power is not perfect because of its low sensitivity to determine the anti-p53 antibodies.

The neoepitopes on methylglyoxal (MG) glycated LDL create autoimmune response; autoimmunity detection in T2DM patients with varying disease duration

AimsNon-enzymatic reaction of biomolecules leads to the formation of advanced glycation end products (AGEs). AGEs plays significant role in the pathophysiology of type 2 diabetes mellitus. Methylglyoxal (MG) is a highly reactive carbonyl compound which causes formation of early (ketoamines), intermediate (dicarbonyls) and advanced glycation end products (AGEs). Glycation also results in the generation of free radicals causing structural perturbations which leads to the generation of neoantigenic epitopes on LDL molecules. The aim of the present study was to investigate whether the modification of LDL results in auto-antibodies generation in type 2 diabetes patients'. MethodsThe binding affinity of circulating autoantibodies in patients against native and MG modified LDL were assessed as compared with healthy and age-matched controls (n = 50) and T2DM patients with disease duration (DD) 5–15 yrs (n = 80) and DD > 15 yrs (n = 50) were examined by direct binding ELISA. KeyfindingsThe high affinity binding were observed in 50% of T2DM with DD 5–15 and 62% of T2DM with DD > 15 of patient's sera antibodies to MG-LDL antigen, in comparison to its native analog (P < 0.05). NHS sera showed negligible binding with both native and glycated LDL. Competitive inhibition ELISA results exhibit greater affinity sera IgG than the direct binding ELISA results. The increase in glycation intermediate and ends product were also observed in T2DM patient's sera and NHS sera. SignificanceThere might be the generation of neoantigenic epitopes on LDL macromoleucle which results in generation of antibodies in T2DM. The prevalence of antibodies was dependent on disease duration.

Predicting factors for disappearance of anti-mutated citrullinated vimentin antibodies in sera of patients with rheumatoid arthritis

Objectives: We aimed to determine the predicting factors for disappearance of anti-mutated citrullinated vimentin antibody (anti-MCV Ab) in sera from rheumatoid arthritis (RA) patients.Methods: In 2013, 95 RA patients whose Disease Activity Score with erythrocyte sedimentation rate were moderate to severe (DAS28-ESR ≥3.2) at baseline were enrolled. Titers of anti-MCV Ab and anti-cyclic citrullinated peptide (anti-CCP) Ab for 2013 and 2014 were measured. The association of anti-MCV disappearance with disease activity, treatment, interstitial lung disease (ILD), and serum markers of ILD were retrospectively examined. Predicting factors of anti-MCV disappearance were determined by multivariable analysis.Results: While anti-CCP positivity rate did not change during the year, anti-MCV Ab changed from positive to negative in 18 patients (=19.0%). Continuous biological disease-modifying anti-rheumatic drug use, prednisolone dose (≥5.0 mg daily), and low KL-6 level (<191 U/mL) were determined as predicting factors of anti-MCV disappearance by multivariable analysis. In our cohort, anti-MCV Ab disappearance was not linked to clinical and radiological improvement.Conclusion: Different from anti-CCP Ab, anti-MCV Ab in sera from RA patients can disappear in a year. Some predicting factors for such negative seroconversion were found, whereas clinical significance of anti-MCV Ab disappearance was undetermined.

Predictors of high molecular weight adiponectin in patients with colorectal cancer

Non-enzymatic reaction of biomolecules leads to the formation of advanced glycation end products (AGEs). AGEs plays significant role in the pathophysiology of type 2 diabetes mellitus. Methylglyoxal (MG) is a highly reactive carbonyl compound which causes formation of early (ketoamines), intermediate (dicarbonyls) and advanced glycation end products (AGEs). Glycation also results in the generation of free radicals causing structural perturbations which leads to the generation of neoantigenic epitopes on LDL molecules. The aim of the present study was to investigate whether the modification of LDL results in auto-antibodies generation in type 2 diabetes patients'.The binding affinity of circulating autoantibodies in patients against native and MG modified LDL were assessed as compared with healthy and age-matched controls (n = 50) and T2DM patients with disease duration (DD) 5–15 yrs (n = 80) and DD > 15 yrs (n = 50) were examined by direct binding ELISA.The high affinity binding were observed in 50% of T2DM with DD 5–15 and 62% of T2DM with DD > 15 of patient's sera antibodies to MG-LDL antigen, in comparison to its native analog (P < 0.05). NHS sera showed negligible binding with both native and glycated LDL. Competitive inhibition ELISA results exhibit greater affinity sera IgG than the direct binding ELISA results. The increase in glycation intermediate and ends product were also observed in T2DM patient's sera and NHS sera.There might be the generation of neoantigenic epitopes on LDL macromoleucle which results in generation of antibodies in T2DM. The prevalence of antibodies was dependent on disease duration.

Detection of Anti-Lactoferrin and Anti-Lysozyme in Ulcerative Colitis Patients

Background: Ulcerative colitis is an autoimmune inflammatory disease. Perinuclear anti-neutrophil cytoplasmic antibodies have been described in patients with inflammatory bowel disease, mainly ulcerative colitis, their role in pathogenesis and diagnostic value are still contentious. Objective: This study targeted at evaluating the incidence of auto antibodies against lactoferrin and lysozyme which belongs to perinuclear antineutrophil cytoplasmic antibodies and measurement the levels of C-reactive protein ,Study the relationship between anti-lactorferrin and anti-lysozyme antibodies , Study the association between anti-lactorferrin, anti-lysozyme antibodies and C-reactive protein concentration among ulcerative colitis patients. Patients and Methods: Fifty patients with ulcerative colitis be present at Al-Kadhimiya Teaching Hospital in Baghdad-Iraq and 25 healthy subjects were selected as the control group. Enzyme linked immune sorbent assay technique was used to detect the anti-lactoferrin and lysozyme antibody in sera of patients and healthy control groups and C- reactive protein was measured by qualitative and semi quantitative agglutination methods. Results: The results of study have showed the male were more affected with UC than female with ratio (1.2:1). The study showed statistically important variances for anti-lactoferrin and lysozyme antibodies between patients and control groups. The present study shown that the (30%) and (38%) of ulcerative colitis patients were seropositive for anti-lactoferrin and lysozyme antibodies, respectively. Conclusion: The prevalence of anti-lactoferrin and anti-lysozyme antibodies were similar to that reported in previous studies and their presence was associated with severity of ulcerative colitis .

Peroxidasin Is a Novel Target of Autoantibodies in Lupus Nephritis

Peroxidasin Is a Novel Target of Autoantibodies in Lupus Nephritis

Anisotropic silver nanoparticles sensitized by oxidized lipoproteins for detection of appropriate antibodies

Antibodies to oxidized lipoproteins are useful markers for diagnosis and prognosis of some heart diseases. Low density lipoproteins (LDL) were purified from human plasma and were oxidized by CuCl2. They were immobilized on anisotropic silver nanoparticles with tunable plasmon resonance band and were applied for detection of appropriate antibodies in sera of patients with stenosis. The presence of such antibodies brings to significant shifting of plasmon resonance band to long-wave region in comparison with control sera. This approach permits to detect such antibodies by rapid method with one step procedure.

Parvovirus B19 in Endomyocardial Biopsy of Patients With Idiopathic Dilated Cardiomyopathy: Foe or Bystander?

Parvovirus B19 (PVB19) has emerged as one of the viruses possibly inducing chronic myocarditis and subsequent idiopathic dilated cardiomyopathy (IDCM). The aim of this work was to investigate the presence and long-term consequences of PVB19-DNA within myocardial biopsies from patients with IDCM and to compare the findings with those from donor hearts (control group). Forty hospitalized IDCM patients (age 47 ± 12 y) with mean left ventricular ejection fraction 27 ± 12% were included. The presence of PVB19-DNA in myocardial biopsies and of IgG and IgM antibodies in patient sera was analyzed. The control group consisted of 20 donor hearts. The follow-up time was 112 ± 57 months. PVB19-DNA was found in myocardial biopsies of both patients (73%) and control samples (55%; P = .25).Three deaths and 8 heart transplantations occurred in the IDCM group, and 6 deaths in the control group (ie, the recipients of the control hearts). No difference in transplantation-free survival between the PVB19-DNA positive/negative IDCM patients or transplant recipients was found. PVB19-DNA is a common finding in both patients with IDCM and in healthy donor hearts, not affecting prognosis. These findings support the view that PVB19 is an innocent bystander, frequently found in myocardium with low DNA copies, and not a plausible cause of IDCM.

Serodiagnosis of Extraintestinal Amebiasis: Retrospective Evaluation of the Diagnostic Performance of the Bordier® ELISA Kit.

Soluble antigens from an axenic culture of Entamoeba histolytica were used to develop a commercial ELISA kit to quantify anti-E. histolytica antibodies in sera of patients with extraintestinal amebiasis in non-endemic settings. The diagnostic specificity and sensitivity of the test were assessed retrospectively using 131 human serum samples with amoebic serologic status available. They were selected according to their results in immunofluorescence (IFAT) and were separated in 2 sample categories: 64 sera with positive results by IFAT and 67 with negative results by IFAT. The sensitivity and specificity of the ELISA kit were assessed at 95.0% and 94.0% compared to the IFAT. The test can be useful to exclude a potential diagnosis of amebiasis and could be used as a screening method since ELISA is an automated technique.

Antibody Production in Response to Staphylococcal MS-1 Phage Cocktail in Patients Undergoing Phage Therapy.

In this study, we investigated the humoral immune response (through the release of IgG, IgA, and IgM antiphage antibodies) to a staphylococcal phage cocktail in patients undergoing experimental phage therapy at the Phage Therapy Unit, Medical Center of the Ludwik Hirszfeld Institute of Immunology and Experimental Therapy in Wrocław, Poland. We also evaluated whether occurring antiphage antibodies had neutralizing properties toward applied phages (K rate). Among 20 examined patients receiving the MS-1 phage cocktail orally and/or locally, the majority did not show a noticeably higher level of antiphage antibodies in their sera during phage administration. Even in those individual cases with an increased immune response, mostly by induction of IgG and IgM, the presence of antiphage antibodies did not translate into unsatisfactory clinical results of phage therapy. On the other hand, a negative outcome of the treatment occurred in some patients who showed relatively weak production of antiphage antibodies before and during treatment. This may imply that possible induction of antiphage antibodies is not an obstacle to the implementation of phage therapy and support our assumption that the outcome of the phage treatment does not primarily depend on the appearance of antiphage antibodies in sera of patients during therapy. These conclusions are in line with our previous findings. The confirmation of this thesis is of great interest as regards the efficacy of phage therapy in humans.

DETECTION OF CASES OF PARVOVIRUS INFECTION IN THE SYSTEM FOR EPIDEMIOLOGICAL SURVEILLANCE OF EXANTHEMATIC DISEASES

The drastic decrease of the incidence of Measles and Rubella at the stage of elimination of these infections is notified on the territory of North- Western Federal Region (NWFR) of Russia. At the same time the number of cases with the error clinical diagnosis of Measles and Rubella increased. The most frequent error is the infection caused by Parvovirus (PVI). The disease is of the independent particular medical and social significance for obstetrics, maternity and childhood protection, blood donation service, transplantation of organs/tissue etc. The aim of the current study was to estimate the prevalence of PVI on the territory of NWFR of Russia in different periods of 2009–2012 and 2015–2016. The data of the laboratory diagnosis of PVI for patients with exanthema were analyzed. Materials and methods. The serum specimens of patients with exanthema from bank of sera of St. Petersburg Subnational Measles/Rubella laboratory, collected in 2009–2012 (n = 495) and in 2015 (n = 336) as well as 69 sera of patients with exanthema from the “Infectious Disease Hospital N30” in St. Petersburg, collected in March-May, 2016 were studied. The specific IgM-PV B19 antibodies were determined by the «recomWELL Parvovirus B19 IgM» (MICROGEN GmbH, Germany) ELISA test-system. The presen ce of the specific IgM-PV B19 antibodies in sera of patients was the evidence of the acute PVI. Results. The obtained results demonstrated the prevalence of PVI on the territory of NWFR. In 2009–2012 as well as in 2015 years PVI was revealed on the overwhelming majority (9 of 11) of administrative territories of the NWFR. The essential predominance of PVI was determined in St. Petersburg and bordering territories of NWFR (Kaliningrad Oblast’, Leningrad Oblast’, Republic of Karelia). In 2010, 2011 and 2015 years the part of sera detected as IgM-PV B19 positive on an average was equal to 14%. Meanwhile in 2012 the part of the detected IgM-PV B19 positive sera was statistically higher (p 0.05) and consisted 45.5% of those tested in St. Petersburg Subnational Measles/Rubella laboratory. According to the results obtained the epidemical increase of PVI incidence was observed on the territory of NWFR in 2012. Among the cases with the laboratory confirmed PVI (i.e. IgM-PV B19 positive sera) the part of cases with the error clinical diagnosis of Rubella consisted 56.2% in 2012 and 34.0% in 2015. Comparing the initial clinical diagnosis of patients from the “Infectious Di sease Hospital N 30” in St. Petersburg in March-May, 2016, with the results of IgM-PV B19 ELISA of sera we revealed that none of patients with the laboratory confirmed PVI had the initial clinical diagnosis PVI at the stage of hospitalization. Thus the results obtained evidence the prevalence of PVI on the territory of NWFR; clinical diagnosis of PVI turns to be the problem for clinicians; the differential diagnosis of PVI with Rubella is necessary and of extremely importance at the stage of elimination of Measles and Rubella in Russia.

Long-term persistence of anti-hantavirus antibodies in sera of patients undergoing hemorrhagic fever with renal syndrome and subjects vaccinated against the disease

Background China has the highest prevalence of hemorrhagic fever with renal syndrome (HFRS) and accounts for 90% of the total cases worldwide. However, the long-term persistence of anti-hantavirus antibodies in sera of patients with HFRS and subjects vaccinated against the disease remains unclear. The aim of the present study was to investigate the prevalence of anti-hantavirus IgG antibodies in sera of patients with prior HFRS, versus subjects vaccinated against the disease and controls in Shaanxi, China. Methods Six hundred individuals were included in this study. We quantified anti-hantavirus IgG antibodies in HFRS patients (n = 100), vaccinees (n = 200), controls from endemic regions (n = 200), and controls from non-endemic regions (n = 100) in China. Results The median optical density (OD) values (range) were 0.803 (0.008–1.813), 0.075 (0.004–1.565), 0.026 (0–1.179), and 0.015 (0.009–0.118) for HFRS patients, vaccinated subjects, endemic controls, and non-endemic controls, respectively. There was a strikingly significant difference between the HFRS group and each non-HFRS group (p < 0.001). The vaccinated subjects were also significantly different from the endemic controls. The time since the acute phase was correlated with the OD values of the HFRS patients. Conclusions Our study suggests that HFRS patients gain long-lasting protection and that vaccination may be an effective way to stimulate antibody production.

Is air pollution a risk factor for rheumatoid arthritis?

Rheumatoid arthritis is a chronic inflammatory debilitating disease triggered by a complex interaction involving genetic and environmental factors. Active smoking and occupational exposures such as silica increase its risk, suggesting that initial inflammation and generation of rheumatoid arthritis-related autoantibodies in the lungs may precede the clinical disease. This hypothesis paved the way to epidemiological studies investigating air pollution as a potential determinant of rheumatoid arthritis. Studies designed for epidemiology of rheumatoid arthritis found a link between traffic, a surrogate of air pollution, and this disease. Furthermore, a small case–control study recently found an association between wood smoke exposure and anticyclic citrullinated protein/peptide antibody in sera of patients presenting wood-smoke-related chronic obstructive pulmonary disease. However, reports addressing impact of specific pollutants on rheumatoid arthritis incidence and severity across populations are somewhat conflicting. In addition to the link reported between other systemic autoimmune rheumatic diseases and particulate matters/gaseous pollutants, experimental observation of exacerbated rheumatoid arthritis incidence and severity in mice models of collagen-induced arthritis after diesel exhaust particles exposure as well as hypovitaminosis D-related autoimmunity can help understand the role of air pollution in rheumatoid arthritis. All these considerations highlight the necessity to extend high quality epidemiological researches investigating different sources of atmospheric pollution across populations and particularly in low-and-middle countries, in order to further explore the biological plausibility of air pollution’s effect in the pathogenesis of rheumatoid arthritis. This should be attempted to better inform policies aiming to reduce the burden of rheumatoid arthritis.

Identification of Cerebral Infarction-Specific Antibody Markers from Autoantibodies Detected in Patients with Systemic Lupus Erythematosus

Background: Systemic lupus erythematosus (SLE) is an autoimmune disease which may be caused by development of the autoantibodies. On the other hand, SLE is a high-risk group of atherosclerosis, so it is possible that some of autoantibodies in SLE are the result of atherosclerosis-related diseases such as cerebral infarction (CI), cardiovascular disease (CVD) and diabetes mellitus (DM). Methods: The initial screening of autoantibodies was performed using the protein array method. AlphaLISA was used to analyze the serum antibody levels using synthetic polypeptides as antigens. Results: After the initial screening using protein array, we identified 67 antigens that were recognized by IgG antibodies in sera of patients with SLE. In the second screening, 170 peptides derived from amino acid sequences of 67 antigens were synthesized and used as antigens for analysis of serum antibody levels by AlphaLISA. The antibody levels for ten peptides were significantly higher in the sera of patients with SLE than in those of healthy donors. Further AlphaLISA analysis of sera of patients with CI, CVD or DM revealed that the serum antibody levels for four peptides derived from SOSTDC1, CTNND1, CLDND1 and CCNG2 were elevated in patients as compared to those of healthy donors. Conclusions: Serum antibody levels against peptide antigens of SOSTDC1, CTNND1, CLDND1 and CCNG2 are useful markers for diagnosis of the progression of CI, CVD and/or DM.

Characterization of a Trichinella spiralis 31 kDa protein and its potential application for the serodiagnosis of trichinellosis

The Trichinella spiralis 31kDa protein (Ts31) was screened from the excretory-secretory (ES) proteins of muscle larvae (ML) by immunoproteomics using serum from mice infected with T. spiralis at 18 days post infection (dpi). The aim of this study was to characterize the Ts31 protein and to evaluate the potential of the recombinant Ts31 protein (rTs31) for serodiagnosis of human trichinellosis. Ts31 gene was cloned and rTs31 was produced in an E. coli expression system. An anti-rTs31serum recognized the native protein migrating in a 25–55kDa range by Western blotting of ML crude or ES antigens. Expression of Ts31 gene was observed at all developmental stages of T. spiralis (adult worms, newborn larvae, pre-encapsulated larvae and ML). An immunolocalization analysis identified Ts31 in the cuticle and stichocytes of the parasite. The sensitivity of rTs31-ELISA and ES antigen ELISA for detecting anti-Trichinella IgG antibodies in sera of patients with trichinellosis was 97.83% (45/46) and 86.78% (39/46), respectively (P>0.05); The specificity of rTs31-ELISA was 99.13% (114/115), which was significantly higher than 85.22% (98/115) of ES antigen ELISA (P<0.01). The rTs31 protein of T. spiralis could be considered as a potential diagnostic antigen for trichinellosis.

Detection of high levels of anti-α-galactosyl antibodies in sera of patients with Old World cutaneous leishmaniasis: a possible tool for diagnosis and biomarker for cure in an elimination setting.

In the Kingdom of Saudi Arabia (KSA), Old World cutaneous leishmaniasis (CL) is mainly caused by Leishmania major and Leishmania tropica parasites. Diagnosis of CL is predominately made by clinicians, who at times fail to detect the disease and are unable to identify parasite species. Here, we report the development of a chemiluminescent enzyme-linked immunosorbent assay (CL-ELISA) to measure the levels of anti-α-galactosyl antibodies in human sera. Using this assay, we have found that individuals infected with either Leishmania spp. had significantly elevated levels (up to 9-fold higher) of anti-α-Gal IgG compared to healthy control individuals. The assay sensitivity was 96% for L. major (95% CI; 94-98%) and 91% for L. tropica (95% CI; 86-98%) infections and therefore equivalent to restriction fragment length polymorphism-polymerase chain reaction analysis of parasite ITS1 gene. In addition, the assay had higher sensitivity than microscopy analysis, which only detected 68 and 45% of the L. major and L. tropica infections, respectively. Interestingly, up to 2 years following confirmed CL cure individuals had 28-fold higher levels of anti-α-Gal IgG compared to healthy volunteers. Monitoring levels of anti-α-Gal antibodies can be exploited as both a diagnostic tool and as a biomarker of cure of Old World CL in disease elimination settings.