[Solid Tumors With Cold Agglutinins:Report of Two Cases and Literature Review].

Cold agglutinins(CA),autoantibodies against the antigen I or i on the surface of red blood cells,are mainly of IgM class,and the majority have κ light chains.They can lead to red blood cell agglutination at decreased body temperature and are usually associated with infections,drug reactions,autoimmune diseases,and hematological malignancies.However,solid tumors with CA are rare.We reported two cases of CA in the peripheral blood of patients with solid tumors.Peripheral complete blood cell count of the patients at admission showed reduced erythrocyte count and hematocrit,mismatching between erythrocyte count and hemoglobin,abnormally elevated levels of mean corpuscular hemoglobin and mean cell hemoglobin concentration.Peripheral blood smear showed erythrocyte aggregation.After the sample was preheated at 37 ℃ for 30 min,the reversibility of red blood cell aggregation was observed,and the erythrocyte parameters were corrected.

Screening Strategy for Islet Autoantibodies in Diabetes Patients of Different Ages.

Background: The detection of islet autoantibodies is essential for the accurate classification and diagnosis of diabetes mellitus (DM). The islet autoantibody distribution varies by age. However, screening strategies for DM patients with different onset ages remain lacking. Materials and Methods: This cross-sectional study included 17,536 DM patients from 46 medical centers across China. The seroprevalence of glutamic acid decarboxylase autoantibody (GADA), insulinoma-associated-2 autoantibody (IA-2A), zinc transporter 8 autoantibody (ZnT8A), and insulin autoantibody (IAA) was determined in younger and older patients with type 1 DM (T1DM) (n = 287 and 285, respectively), younger and older patients with latent autoimmune diabetes (LAD) (n = 140 and 121, respectively), and younger and older patients with type 2 DM (n = 200 in each group). Results: The cutoff age between younger and older patients was 35 years using restricted cubic spline method (n = 17,536, adjusted R2 = 0.97, residual standard error = 1.32; P < 0.001). The seroprevalence rates of four islet autoantibodies were higher in patients aged 15-35 years than in those ≥35 years (GADA: 17% vs. 5.6%, IA-2A: 8.5% vs. 1.3%, ZnT8A: 6.3% vs. 2.3%, IAA: 2.2% vs. 1.0%). The prevalence of ZnT8A was higher in LAD patients than in T1DM patients, especially in older LAD patients. The results indicated that ZnT8A detection can increase the detection rate of older LAD patients from 70.2% (based on GADA detection alone) to 91.7%. Conclusions: In patients stratified according to the cutoff age of 35 years, the optimal detection sequence should be GADA, IA-2A, and ZnT8A in younger patients and GADA, ZnT8A, and IA-2A in older patients, so as to reduce the screening cost while improving the detection rate. Particularly, the ZnT8A test is recommended in older patients to avoid a missed LAD diagnosis.

Development of ACE2 autoantibodies after SARS-CoV-2 infection.

BACKGROUND: Activation of the immune system is implicated in the Post-Acute Sequelae after SARS-CoV-2 infection (PASC) but the mechanisms remain unknown. Angiotensin-converting enzyme 2 (ACE2) cleaves angiotensin II (Ang II) resulting in decreased activation of the AT1 receptor and decreased immune system activation. We hypothesized that autoantibodies against ACE2 may develop after SARS-CoV-2 infection, as anti-idiotypic antibodies to anti-spike protein antibodies. METHODS AND FINDINGS: We tested plasma or serum for ACE2 antibodies in 67 patients with known SARS-CoV-2 infection and 13 with no history of infection. None of the 13 patients without history of SARS-CoV-2 infection and 1 of the 20 outpatients that had a positive PCR test for SARS-CoV-2 had levels of ACE2 antibodies above the cutoff threshold. In contrast, 26/32 (81%) in the convalescent group and 14/15 (93%) of patients acutely hospitalized had detectable ACE2 antibodies. Plasma from patients with antibodies against ACE2 had less soluble ACE2 activity in plasma but similar amounts of ACE2 protein compared to patients without ACE2 antibodies. We measured the capacity of the samples to inhibit ACE2 enzyme activity. Addition of plasma from patients with ACE2 antibodies led to decreased activity of an exogenous preparation of ACE2 compared to patients that did not have antibodies. CONCLUSIONS: Many patients with a history of SARS-CoV-2 infection have antibodies specific for ACE2. Patients with ACE2 antibodies have lower activity of soluble ACE2 in plasma. Plasma from these patients also inhibits exogenous ACE2 activity. These findings are consistent with the hypothesis that ACE2 antibodies develop after SARS-CoV-2 infection and decrease ACE2 activity. This could lead to an increase in the abundance of Ang II, which causes a proinflammatory state that triggers symptoms of PASC.

Multiple Sclerosis: Enzymatic Cross Site-Specific Hydrolysis of H1 Histone by IgGs against H1, H2A, H2B, H3, H4 Histones, and Myelin Basic Protein.

Histones play a key role in chromatin remodeling and gene transcription. Further, free histones in the blood act as damage-associated molecules. Administration of histones to animals results in systemic inflammatory and toxic effects. Myelin basic protein is the principal constituent element of the myelin-proteolipid sheath of axons. Abzymes (antibodies with catalytic activities) are the original features of some autoimmune diseases. In this study, electrophoretically homogeneous IgGs against H1, H2A, H2B, H3, and H4 histones and myelin basic protein (MBP) were isolated from the blood sera of multiple sclerosis (MS) patients by several affinity chromatographies. Using MALDI mass spectrometry, the sites of H1 histone cleavage by IgGs against H1, H2A, H2B, H3, H4, and MBP were determined. It was shown that IgGs against H1 split H1 at 12 sites, while the number of cleavage sites by abzymes against other histones was lower: H2A (9), H2B (7), H3 (3), and H4 (3). The minimum rate of H1 hydrolysis was observed for antibodies against H3 and H4. A high rate of hydrolysis and the maximum number of H1 hydrolysis sites (17) were found for antibodies against MBP. Only a few sites of H1 hydrolysis by anti-H1 antibodies coincided with those for IgGs against H2A, H2B, H3, H4, and MBP. Thus, the polyreactivity of complexation and the enzymatic cross-activity of antibodies against H1, four other histones, and MBP have first been shown. Since histones act as damage molecules, abzymes against histones and MBP can play a negative role in the pathogenesis of MS and probably other different diseases as well.

Immune recognition of lysyl-tRNA synthetase and isoleucyl-tRNA synthetase by anti-OJ antibody-positive sera.

OBJECTIVE: Anti-aminoacyl-tRNA synthetase (anti-ARS) antibodies are useful for identifying a clinical subset of patients with idiopathic inflammatory myopathies (IIMs). Anti-OJ antibodies, which recognize multi-enzyme synthetase complexes including isoleucyl-tRNA synthetase (IARS) and lysyl-tRNA synthetase (KARS), are among the anti-ARS antibodies. Although testing antibodies to other ARSs have been used clinically, no validated immunoassays for detecting anti-OJ antibodies are available. We aimed to establish an anti-OJ ELISA. METHODS: Serum samples were collected from 279 patients with IIMs and 22 patients with idiopathic interstitial pneumonia. Sixty-four of the samples that had been confirmed to be negative for anti-OJ by standard immunoprecipitation were used as the negative control, and 12 anti-OJ-positive reference sera were used as the positive control. Antibodies to IARS and KARS were assayed by ELISA using biotinylated recombinant proteins generated by in vitro transcription/translation. RESULTS: The anti-OJ-positive sera strongly reacted with the KARS and IARS recombinant proteins in ELISA. Although all 12 reference sera were positive in the anti-KARS ELISA, 4 of the 64 anti-OJ-negative sera were also weakly positive. The sensitivity and the specificity were 100% and 93.8%, respectively. Since our anti-KARS ELISA performed well, showing a high agreement with the results for immunoprecipitation (Cohen's κ > 0.8), the remaining 237 samples were also tested. Thirteen anti-KARS-positive sera were newly found by ELISA, all of which were anti-OJ positive by immunoprecipitation. CONCLUSION: Immunoassays for detecting anti-OJ antibodies using KARS and IARS recombinant proteins were developed. Our ELISAs performed well, with very high agreement of the results by immunoprecipitation and can be applied to the first reliable, easy-to-use measurement assays for anti-OJ antibodies.

Autoantibody against angiotensin II type I receptor induces pancreatic ß-cell apoptosis via enhancing autophagy.

Autoantibody against the angiotensin II type I receptor (AT1-AA) has been found in the serum of patients with diabetes mellitus (DM). However, it remains unclear whether AT1-AA induces ß-cell apoptosis and participates in the development of DM. In this study, an AT1-AA-positive rat model was set up by active immunization, and AT1-AA IgG was purified. INS-1 cells were treated with AT1-AA, and cell viability, apoptosis, and autophagy-related proteins were detected by Cell Counting Kit-8 assay, flow cytometry, and western blot analysis, respectively. Results showed that existence of AT1-AA impaired the islet function and increased the apoptosis of pancreatic islet cells in rats, and the autophagy level in rat pancreatic islet tissues tended to increase gradually with the prolongation of immunization time. AT1-AA markedly reduced INS-1 cell viability, promoted cell apoptosis, and decreased insulin secretion in vitro. In addition, the autophagy level was gradually increased along with the prolongation of AT1-AA treatment time. Meanwhile, it was determined that treatment with autophagy inhibitor 3-methyladenine and angiotensin II type 1 receptor (AT1R) blocker telmisartan could improve insulin secretion and apoptosis in vitro and in vivo. In conclusion, it is deduced that upregulation of autophagy contributed to the AT1-AA-induced ß-cell apoptosis and islet dysfunction, and AT1R mediated the signal transduction.

Anti-C1q Autoantibodies: Standard Quantification and Innovative ELISA.

Autoantibodies against complement C1q (anti-C1q) are an excellent marker for active nephritis in SLE patients. Here, we describe a typical protocol for the quantification of anti-C1q using immobilized C1q (important for the presentation of relevant cryptic epitopes) and a high salt buffer for the incubation steps (to prevent immune-complex binding to intact C1q). More recently, a linear epitope on the C1q A chain, that is targeted by anti-C1q, has been described (A08). The assay using this peptide seems to be more specific and more sensitive for the detection of active nephritis in SLE patients than the conventional anti-C1q assay, but further studies are required to establish the role of anti-A08 of C1q in the clinical routine.

Anti-Ficolin-2 and Anti-Ficolin-3 Autoantibody Detection by ELISA.

Ficolins are recognition proteins of the lectin pathway of the complement system and also play an important role in innate immunity and in the maintenance of tissue homeostasis. They deserve special attention in the context of autoimmunity since they are involved in the uptake of dying cells. Because the monitoring of systemic lupus erythematosus (SLE) patients is particularly difficult, it is crucial to find new relevant serum biomarkers. The ability to detect autoantibodies in the patients' sera provides a diagnostic and prognostic advantage. We describe in this chapter quantitative enzyme linked immunosorbent assays (ELISA) to detect the presence of autoantibodies targeting ficolin-2 and ficolin-3 in human sera. Recombinant ficolins produced in a mammalian expression system are used as coating antigens. The described in-house ELISAs provide a valuable tool to efficiently quantify anti-ficolin autoantibodies in the sera of SLE patients.

Plasma Exchange to Rescue Patients with Autoantibodies Against Type I Interferons and Life-Threatening COVID-19 Pneumonia.

PURPOSE: To report four cases of life-threatening COVID-19 pneumonia in patients with high blood concentrations of neutralizing autoantibodies against type I interferons (IFNs), who were treated with plasma exchange (PE) as a rescue therapy. METHODS: Prospective case series, which included patients, diagnosed with RT-PCR-confirmed SARS-CoV-2 infection and positive autoantibodies against type I IFNs in two French intensive care units (ICUs) between October 8 and November 14, 2020. Six critically ill COVID-19 patients with no anti-IFN antibodies were used as controls. Anti-IFN autoantibodies and IFN concentrations, together with the levels of anti-SARS-CoV-2 antibodies, were measured sequentially in serum. Viral load was determined in the upper and lower respiratory tract. Patients were followed during hospital stay. RESULTS: Three men and one woman were included. Three of the patients had four PE sessions each, while another had three PE sessions. PE decreased the concentrations of autoantibodies against type I IFN in all four patients, whereas anti-SARS-CoV-2 antibody levels remained stable. Autoantibodies against type I IFN levels were high in tracheal aspirates of one patient and decreased after three PE sessions. By contrast, anti-IFN autoantibodies were not detected in tracheal aspirates from five control patients without detectable anti-IFN autoantibodies in serum. During PE, serum IFN-α levels slightly increased in three out of four patients, and upper respiratory tract viral load decreased in all patients. All patients were alive at day 28 of ICU admission. Two patients eventually died in the ICU, while the two survivors were discharged from the ICU at days 50 and 66. CONCLUSIONS: PE efficiently removes autoantibodies against type I IFNs, including those detected in tracheal aspirates, without affecting anti-SARS-CoV-2 antibody levels, in patients with life-threatening COVID-19 pneumonia. The clinical benefit of PE in patients with autoantibodies against type I IFNs should be tested in a larger study.

Recurrence in long-term survivor of anti-MDA5 antibody-positive clinically amyopathic dermatomyositis: case series and literature review.

Anti-MDA5 antibody-positive clinically amyopathic dermatomyositis (CADM) is often complicated by rapidly progressive interstitial lung disease and is associated with poor prognosis. However, even though recurrence is reported to be infrequent if successful medical treatment is administered, the long-term prognosis remains unclear. In this case report, we examined the clinical features and treatment details of three patients with anti-MDA5 antibody-positive CADM with multiple recurrences during long-term survival at Juntendo University Urayasu Hospital. Of the three patients, two failed to convert to an anti-MDA5 antibody-negative status, and one patient died. One of the remaining patients experienced two relapses but eventually tested negative for anti-MDA5 antibodies and showed a relatively stable clinical course. Although cases of recurring anti-MDA5 antibody-positive CADM rarely occur, they may occasionally be fatal. The prognosis for anti-MDA5 antibody-positive CADM has improved over time owing to its establishment as a disease. However, further information and research is necessary to ascertain its long-term prognosis.

Serum naturally occurring anti-TDP-43 auto-antibodies are increased in amyotrophic lateral sclerosis.

Amyotrophic Lateral Sclerosis (ALS) patients express significant clinical heterogeneity that often hinders a correct diagnostic definition. Intracellular deposition of TDP-43, a protein involved in RNA metabolism characterizes the pathology. Interestingly, this protein can be detected in serum, wherein cognate naturally-occurring auto-antibodies (anti-TDP-43 NAb) might be also present, albeit they have never been documented before. In this exploratory study, we quantified the levels of both anti-TDP-43 NAb and TDP-43 protein as putative accessible markers for improving the ALS diagnostic process by using ELISA in N = 70 ALS patients (N = 4 carrying TARDBP mutations), N = 40 age-comparable healthy controls (CTRL), N = 20 motor neuron disease mimics (MN-m), N = 20 Alzheimer's disease (AD) and N = 15 frontotemporal lobar degeneration (FTLD) patients. Anti-TDP-43 NAb were found to be significantly increased in ALS patients compared to all the other groups (p < 0.001). On the other hand, the distribution of serum levels of TDP-43 protein was highly variable among the various groups. Levels were increased in ALS patients, albeit the highest values were detected in MN-m patients. NAb and protein serum levels failed to correlate. For the first time, we report that serum anti-TDP-43 NAb are detectable in human serum of both healthy controls and patients affected by a variety of neurodegenerative disorders; furthermore, their levels are increased in ALS patients, representing a potentially interesting trait core marker of this disease. Further studies are needed to clarify the exact role of the NAb. This information might be extremely useful for paving the way toward targeting TDP-43 by immunotherapy in ALS.

Update of the simplified criteria for autoimmune hepatitis: Evaluation of the methodology for immunoserological testing.

BACKGROUND & AIMS: The simplified criteria for the diagnosis of autoimmune hepatitis (AIH) include immunofluorescence testing (IFT) of antinuclear and smooth muscle autoantibodies (ANA and SMA) on rodent tissue sections. We aimed to establish scoring criteria for the implementation of ANA IFT on human epithelioma-2 (HEp-2) cells and ELISA-based testing. METHODS: ANA and SMA reactivity of 61 AIH sera and 72 non-alcoholic fatty liver disease controls were separately assessed on tissue sections and HEp-2 cells to compare the diagnostic value at increasing titers. A total of 113 patients with AIH at diagnosis and 202 controls from 3 European centers were assessed by IFT as well as 3 different commercially available ANA ELISA and 1 anti-F-actin ELISA. RESULTS: ANA assessment by IFT on liver sections had 83.6% sensitivity and 69.4% specificity for AIH at a titer of 1:40. On HEp-2 cells, sensitivity and specificity were 75.4% and 73.6%, respectively, at an adjusted titer of 1:160. Area under the curve (AUC) values of ANA ELISA ranged from 0.70-0.87, with ELISA coated with HEp-2 extracts in addition to selected antigens performing significantly better. SMA assessment by IFT had the highest specificity for the SMA-VG/T pattern and anti-microfilament reactivity on HEp-2 cells. ELISA-based anti-F-actin evaluation was a strong predictor of AIH (AUC 0.88) and performed better than SMA assessment by IFT (AUC 0.77-0.87). CONCLUSION: At adjusted cut-offs, both ANA IFT using HEp-2 cells and ELISA-based autoantibody evaluation for ANA and SMA are potential alternatives to tissue-based IFT for the diagnosis of AIH. LAY SUMMARY: Autoantibodies are a hallmark of autoimmune hepatitis and are traditionally tested for by immunofluorescence assays on rodent tissue sections. Herein, we demonstrate that human epithelioma cells can be used as a reliable substrate for immunofluorescence testing. ELISA-based testing is also a potentially reliable alternative for autoantibody assessment in autoimmune hepatitis. We propose the implementation of these testing methods into the simplified criteria for the diagnosis of autoimmune hepatitis.

Coexistencia de lupus eritematoso sistémico y miastenia gravis. Una expresión infrecuente de poliautoinmunidad / Coexistence of systemic lupus erythematosus and myasthenia gravis: an unusual case of polyautoimmunity

La relevancia clínica de la poliautoinmunidad, definida como la presencia de 2o más enfermedades autoinmunes en un mismo individuo, es uno de los temas aun sin dilucidar en la práctica médica. La coexistencia entre miastenia gravis (MG) y lupus eritematoso sistémico (LES) supone un reto clínico por los posibles diagnósticos diferenciales dados en el momento de abordar el compromiso muscular en pacientes con LES. Presentamos el caso de una paciente que consultó a urgencias del Hospital Universitario San Ignacio de Bogotá, Colombia, con diagnóstico previo de LES, que desarrolla un síndrome de debilidad aguda en el contexto de una infección sistémica, haciendo diagnóstico clínico y electrofisiológico de MG

The relevance of polyautoimmunity, defined as the presence of 2or more autoimmune diseases in the same individual, is one of the issues not yet elucidated in medical practice. The coexistence of myasthenia gravis (MG) and systemic lupus erythematosus (SLE) is a clinical challenge due to the possible differential diagnoses of muscle involvement in patients with SLE. We present the case of a patient who came to the emergency room of Hospital Universitario San Ignacio in Bogotá, Colombia, with a previous diagnosis of SLE, who developed acute weakness in the context of a systemic infection, with a clinical and electrophysiological diagnosis of MG

Isolation of monoclonal antibodies from anti-synthetase syndrome patients and affinity maturation by recombination of independent somatic variants.

The autoimmune disease known as Jo-1 positive anti-synthetase syndrome (ASS) is characterized by circulating antibody titers to histidyl-tRNA synthetase (HARS), which may play a role in modulating the non-canonical functions of HARS. Monoclonal antibodies to HARS were isolated by single-cell screening and sequencing from three Jo-1 positive ASS patients and shown to be of high affinity, covering diverse epitope space. The immune response was further characterized by repertoire sequencing from the most productive of the donor samples. In line with previous studies of autoimmune repertoires, these antibodies tended to have long complementarity-determining region H3 sequences with more positive-charged residues than average. Clones of interest were clustered into groups with related sequences, allowing us to observe different somatic mutations in related clones. We postulated that these had found alternate structural solutions for high affinity binding, but that mutations might be transferable between clones to further enhance binding affinity. Transfer of somatic mutations between antibodies within the same clonal group was able to enhance binding affinity in a number of cases, including beneficial transfer of a mutation from a lower affinity clone into one of higher affinity. Affinity enhancement was seen with mutation transfer both between related single-cell clones, and directly from related repertoire sequences. To our knowledge, this is the first demonstration of somatic hypermutation transfer from repertoire sequences to further mature in vivo derived antibodies, and represents an additional tool to aid in affinity maturation for the development of antibodies.

Sobre la capacidad discriminativa de diferentes autoanticuerpos en el diagnóstico del Lupus Eritematoso Sistémico / On the discriminative capacity of several autoantibodies for the diagnosis of Systemic Lupus Erythematosus

INTRODUCCIÓN: Se han propuesto varios autoanticuerpos en el diagnóstico diferencial del Lupus Eritematoso Sistémico (LES). El uso de estos autoanticuerpos puede resultar en diferentes características operacionales. OBJETIVO: Evaluar las características operacionales de autoanticuerpos selectos en el diagnóstico diferencial del LES. DISEÑO DEL ESTUDIO: Retrospectivo, analítico. SERIE DE ESTUDIO: Ciento sesenta y nueve sujetos (LES: 35.5 %; Enfermedades del tejido conectivo diferentes del LES: 38.5 %; Sujetos aparentemente sanos: 26.0 %; Mujeres: 84.6 %; Edad promedio: 30.9 ± 17.9 años; Tiempo promedio de evolución de la enfermedad lúpica: 3.9 ± 4.7 años). MÉTODOS: Los anticuerpos anti-ADN de doble cadena (anti-ADNdc), anti-nucleosomas (anti-Nuc), anti-proteína Smith (anti-Sm) y anti-ribosomas P (anti-Rib P) se determinaron mediante técnicas inmunoenzimáticas (Orgentec Diagnostika, Mainz, Alemania). Los anticuerpos antinucleares (ANA) se determinaron indistintamente mediante técnicas inmunoenzimáticas (ANA-EIA) e inmunofluorescentes con células Hep2 (ANA-Hep2). Se calcularon las características operacionales de los autoanticuerpos en el diagnóstico diferencial del LES. Asimismo, se obtuvieron las correspondientes curvas ROC en cada instancia de análisis, y se estimó la exactitud diagnóstica del anticuerpo del área bajo la curva ROC (AROC). RESULTADOS: La exactitud de los anticuerpos empleados en el diagnóstico diferencial del LES fue como sigue (en orden descendente): anti-ADNdc: 0.9528 ± 0.0288; anti-Nuc: 0.7851 ± 0.0675; ANA-EIA: 0.7755 ± 0.2633; anti-Sm: 0.5926 ± 0.0790; anti-Rib P: 0.5770 ± 0.2641; y ANA-Hep2: 0.5341 ± 0.2635; respectivamente. Excepción hecha de los anti-ADNdc, las características operacionales de los otros anticuerpos fueron dependientes del punto de corte, la subpoblación muestreada, y el método analítico. CONCLUSIONES: Los anticuerpos anti-ADNdc son los más exactos en el diagnóstico diferencial del LES

RATIONALE: Several autoantibodies have been proposed for the differential diagnosis of Systemic Lupus Erythematosus (SLE). Use of these autoantibodies might result in different operational characteristics. OBJECTIVE: To assess the operational characteristics of selected autoantibodies in the differential diagnosis of SLE. STUDY DISIG: Retrospective analytical. STUDY SERIE: One-hundred and sixty-nine subjects (SLE: 35.5 %; Non-SLE diseases of connective tissue: 38.5 %; Apparently healthy subjects: 26.0 %; Women: 84.6 %; Average age: 30.9 ± 17.9 years; Average evolution time of lupic disease: 3.9 ± 4.7 years). METHODS: Anti-double stranded DNA (anti-dsDNAdc), anti-nucleosomes (anti-Nuc), anti-Smith protein (anti-Sm) and anti-ribosomes (anti-Rib) autoantibodies were determined by immunoenzymatic techniques (Orgentec Diagnostika, Mainz, Alemania). Anti-nuclear antibodies (ANA) were indistinctely determined either by immunoenzimatic techniques (ANA-EIA) or immunofluorescent methods with Hep2 cells (ANA-Hep2). Operational characteristics of the autoantibodies in the differential diagnosis of SLE were calculated. In addition, corresponding ROC curves for each instance of analysis were obtained, and diagnostic accuracy was estimated from the area under the ROC curve (AROC). RESULTS: Accuracy of the autoantibodies used in the differential diagnosis of SLE was as follows (in descending order): anti-dsDNA: 0.9528 ± 0.0288; anti-Nuc: 0.7851 ± 0.0675; ANA-EIA: 0.7755 ± 0.2633; anti-Sm: 0.5926 ± 0.0790; anti-Rib: 0.5770 ± 0.2641; and ANA-Hep2: 0.5341 ± 0.2635; respectively. With the exception of anti-dcDNA, operational characteristics of the remaining antibodies were dependent upon cut-off value, sampled subpopulation, and analytical method. CONCLUSIONS: anti-dsDNA antibodies were the most accurate in the differential diagnosis of SLE

Frequência de anticorpos irregulares identificados em pacientes atendidos em um hemonúcleo no sudoeste do Paraná no ano de 2017 / Frequency of irregular antibodies identified in patients treated at the hemotherapy service in southwest of Paraná in 2017

Quando um indivíduo é exposto a antígenos eritrocitários não próprios, ocorre uma resposta imunológica, que leva à produção de anticorpos irregulares voltados contra esses antígenos. Esse processo é conhecido como aloimunização eritrocitária e acontece em decorrência de transfusões de sangue ou gestações incompatíveis. Na medicina transfusional a pesquisa de anticorpos irregulares é fundamental, pois a falha na detecção de um aloanticorpo pode provocar reações transfusionais, aloimunizações, anemias hemolíticas autoimunes e doença hemolítica perinatal. Este estudo tem por objetivo analisar a frequência de anticorpos irregulares de pacientes atendidos no Hemocentro Regional de Francisco Beltrão, Paraná, no ano de 2017. Os dados foram coletados a partir da revisão de registros em arquivos do Laboratório de Imunohematologia do Hemonúcleo. Foram avaliados dados de 49 protocolos de pacientes que apresentaram dificuldades transfusionais no ano de 2017. Dentre os pesquisados, 37 pacientes (75,5%) apresentaram anticorpos irregulares. Dentre os anticorpos anti-eritrocitários observados neste estudo, evidenciou-se a presença de doze pacientes com anti-D (27,2%), seis pacientes com anti-K (13,6%), quatro pacientes com anti-C (9,0%) e em seis pacientes (13,6%) foi observada a presença de autoanticorpos. Este estudo indica que, nos pacientes transfundidos, os anticorpos mais frequentes foram os aloanticorpos Anti-D do Sistema Rh, provavelmente devido ao seu alto grau de imunogenicidade. A prevalência desses anticorpos é semelhante a vários estudos encontrados na literatura.

When an individual is exposed to not-self red blood cell antigens, an immune response occurs, which leads to the production of irregular antibodies directed against these antigens. This process is known as erythrocyte alloimmunization and occurs as a result of blood transfusions or incompatible pregnancies. In transfusion medicine, the search for irregular antibodies is essential, since failure to detect an alloantibody can cause transfusion reactions, alloimmunizations, autoimmune hemolytic anemias, and perinatal hemolytic disease. This study aims at analyzing the frequency of irregular antibodies of patients seen at the Regional Blood Center of Francisco Beltrão, Paraná, in 2017. The data were collected from the review of records in files of the Immunohematology Laboratory of Hemonúcleo. Data from 49 protocols of patients who had transfusion difficulties in 2017 were evaluated. Among those surveyed, 37 patients (75.5%) had irregular antibodies. Among the anti-erythrocyte antibodies observed in this study, the presence of twelve patients with anti-D (27.2%), six patients with anti-K (13.6%), four patients with anti-C (9.0 %), and in six patients (13.6%) with the presence of autoantibodies were observed. This study indicates that, in transfused patients, the most frequent antibodies were the Rh System Anti-D alloantibodies, probably due to their high degree of immunogenicity. The prevalence of these antibodies is similar to several studies found in the literature.

Detection of putative autoantibodies in systemic lupus erythematous using a novel native-conformation protein microarray platform.

OBJECTIVE: Conventional immunoassays detect autoantibodies related to systemic lupus erythematosus (SLE) via recognition of epitopes on autoantigens expressed in their denatured rather than native conformational state, casting difficulty in evaluating the genuine pathogenicity of the autoantibodies. We aimed to use a novel high-throughput protein microarray platform to identify autoantibodies against native autoantigens in SLE sera. METHODS: Sera from SLE patients and those of gender-, age-, and ethnicity-matched healthy controls (HC) were screened against more than 1,600 immune-related antigens of native conformation. The relative fluorescent unit readout from post-assay imaging were subjected to bioinformatics pre-processing and composite normalization. A penetrance fold change (pFC) analysis between SLE and HC samples shortlisted 50 autoantigens that were subjected to an unsupervised cluster analysis. Correlations between the pFC of putative autoantigens and clinical parameters including SLE disease activity index (SLEDAI-2K) and recent SLE flares were explored. RESULTS: 381 autoantigens were identified when 15 SLE and 15 HC serum samples were compared. The top 20 autoantigens which elicited autoantibody responses in SLE sera filtered based on the highest pFC were further analyzed. Autoantigens which the putative autoantibodies reacted against are those involved in chromatin organization such as DEK, regulation of transcription activity including REOX4 and ELF4, and negative regulation of NFkB activity such as TRIB3. Additionally, the pFC of these autoantibodies significantly and positively correlated with SLEDAI-2K and recent SLE flares. CONCLUSION: A high-throughput protein microarray platform allows detection and quantification of putative lupus-related autoantibodies which are of potential pathophysiological and prognostic significance in SLE patients.