Exploring the Possible Prognostic Role of B-Lymphocyte Stimulator (BLyS) in a Large Series of Patients with Neuroendocrine Tumors.

BACKGROUND AND OBJECTIVE: BLyS (B-Lymphocyte stimulator) is over-expressed in several tumoral settings, with direct or indirect effects on neoplastic proliferation and possibly representing a therapeutic target. In this study, we explored the role of BLyS in a large population of patients with neuroendocrine tumors (NETs). METHODS: The study analyzed the stored sera of 124 consecutive unselected patients with NETs: 36 lung carcinoids (24 typical, 12 atypical), 47 gastroenteric tract and 41 pancreatic (30 non-functioning and 11 functioning: 9 insulinomas, 2 glucagonomas). In 23 cases, BLyS was repeatedly assessed during the follow-up and the disease was monitored (progression, stabilization or remission) according to the RECIST criteria. Patients were compared to 92 age and sex-matched blood donors (BDs). Serum levels of BLyS and Chromogranin A (CgA) were analyzed by ELISA. RESULTS: NET patients showed significantly higher BLyS levels than BDs (1274±809 pg/ml vs. 587±173 pg/ml; p<0.0001). BLyS correlated weakly with CgA (r=0.19 and p=0.035) but did not correlate with Ki67, grading, metastasis, histological type and site. In patients with sustained remission after surgery, BLyS and CgA both showed a gradual reduction over time. Patients with progressing disease showed higher BLyS levels compared to stable patients (1524±694 pg/ml vs. 1168± 373 pg/ml; p= 0.033). BLyS serum levels remained stable in remission and therapy-controlled patients, while increased in the follow-up of progressing cases. CONCLUSION: Higher BLyS levels identify patients with a more severe disease, characterized by progression despite treatments, possibly representing a factor implicated in the proliferation of the neoplastic cells or in sustaining the neoplastic environment.

Coeliac disease in infants: antibodies to deamidated gliadin peptide come first!

BACKGROUND: The onset of coeliac disease (CD) in the first year of life is uncommon and the diagnosis can be challenging due to the suboptimal sensitivity of tissue transglutaminase antibodies (tTG) at this age and the many other possible causes of malabsorption in infants. Antibodies to deamidated gliadin peptides (anti-DGPs), especially IgG, may appear earlier than IgA anti-tTG in very young children with CD. CASE PRESENTATION: We report here on an 8-month-old child who was evaluated for failure to thrive, constipation and developmental delay. The symptoms started following gluten introduction in the diet. Laboratory tests showed high fecal elastase concentration, normal serum IgA levels with positive IgG and IgA anti-DGPs, whereas anti-tTG were not detected. The duodenal biopsy revealed a complete villous atrophy (Marsh-Oberhuber 3C). The culture of biopsy fragments in the presence of gliadin peptides did not stimulate the production of IgA anti-endomysial antibodies. Genetic testing proved the child was positive for HLA-DQ2 (DQA1*05; DQB1*02) and HLA-DQ8 (DQA1*03, DQB1*0302). Having initiated the gluten-free diet, the symptoms disappeared and the infant experienced rapid catch-up growth with normalization of psychomotor development. CONCLUSIONS: This case report highlights the utility of anti-DGPs for screening infants with suspected CD. The pattern with positivity for IgG and IgA anti-DGPs only is rare in IgA-competent children with biopsy-proven CD. It could be explained in infancy as immaturity of the adaptive immune system.

Exploring the plasmatic platelet-activating factor acetylhydrolase activity in patients with anti-phospholipid antibodies.

PURPOSE: To explore the role of plasmatic platelet-activating factor acetylhydrolase (PAF-AH), a marker of cardiovascular risk, in patients with anti-phospholipid antibodies (aPL). METHODS: PAF-AH activity was assessed in a series of 167 unselected patients screened for aPL in a context of thrombotic events, risk of thrombosis or obstetric complications and in 77 blood donors. RESULTS: 116/167 patients showed positive results for at least one aPL among IgG/IgM anti-prothrombin/phosphatidylserine (aPS/PT), anti-cardiolipin (aCL), anti-beta2-glycoprotein I (aß2GPI) or lupus anticoagulant (LAC), while 51/167 patients resulted aPL-negative. LAC+ patients disclosed higher PAF-AH than LAC-negative (22.1 ± 6.4 nmol/min/ml vs. 19.5 ± 4.1 nmol/min/ml; p = 0.0032), and aPL-negative patients (p = 0.03). Patients presenting positive IgG aß2GPI disclosed higher PAF-AH than patients with only IgM aß2GPI-positive antibodies (23.1 ± 7.2 nmol/min/ml vs. 20.1 ± 5.3 nmol/min/ml; p = 0.035), as well as than patients showing only isolated LAC, aCL or aPS/PT (16.9 ± 3.8 nmol/min/ml; p = 0.003). CONCLUSIONS: PAF-AH plasmatic activity is particularly up-regulated in LAC+ and in aß2GPI IgG+ patients, possibly representing an alternative prognostic biomarker for the therapeutic management of APS patients.

The ANA-reflex test as a model for improving clinical appropriateness in autoimmune diagnostics.

Reflex tests are widely used in clinical laboratories, for example, to diagnose thyroid disorders or in the follow-up of prostate cancer. Reflex tests for antinuclear antibodies (ANA) have recently gained attention as a way to improve appropriateness in the immunological diagnosis of autoimmune rheumatic diseases and avoid waste of resources. However, the ANA-reflex test is not as simple as other consolidated reflex tests (the TSH-reflex tests or the PSA-reflex tests) because of the intrinsic complexity of the ANA test performed by the indirect immunofluorescence method on cellular substrates. The wide heterogeneity of the ANA patterns, which need correct interpretation, and the subsequent choice of the most appropriate confirmatory test (ANA subserology), which depend on the pattern feature and on clinical information, hinder any informatics automation, and require the pathologist's intervention. In this review, the Study Group on Autoimmune Diseases of the Italian Society of Clinical Pathology and Laboratory Medicine provides some indications on the configuration of the ANA-reflex test, using two different approaches depending on whether clinical information is available or not. We further give some suggestions on how to report results of the ANA-reflex test.

Anti-DFS70 antibodies detected by immunoblot methods: A reliable tool to confirm the dense fine speckles ANA pattern.

BACKGROUND: Autoantibodies to the DFS70 (dense fine speckles 70) protein have been identified among the antinuclear antibodies (ANA) in patients with various disorders. However, the ANA test in indirect immunofluorescence (IIF) is not a reliable method to identify anti-DFS70 antibodies. We undertook this study to evaluate the diagnostic performance of two new immunoblot methods for the detection of anti-DFS70 antibodies and to investigate whether their different DFS70 antigen composition could affect diagnostic accuracy in detecting anti-DFS70 antibodies. METHODS: 62 samples showing a DFS70 staining pattern by IIF were tested by dot blot (Alphadia) and line blot (Euroimmun) methods. The dot blot method employs a truncated sequence of the DFS70 antigen (residues 349-435), while the line blot uses the full-length protein (aa 1-530). The 62 samples were previously assayed by a chemoluminescent (CLIA) method also using a truncated antigen (aa 349-435): 27 were CLIA positive and 35 were CLIA negative. 120 sera from subjects with infectious diseases were used as controls. RESULT: Both immunoblot methods were positive in the 27 IIF/CLIA positive samples; in addition, the Alphadia dot blot identified another seven DFS70 samples and the Euroimmun line blot was positive in five samples that were negative by CLIA. Among the 120 control samples, two false positives were recorded for the CLIA method, six for the Alphadia method and four for the Euroimmun method. Therefore, in this selected series of samples, sensitivity and specificity were 43.5% and 98.3% for the CLIA method, 54.8% and 95% for the dot blot and 51.6% and 96.6% for the line blot, respectively. CONCLUSIONS: Because of great inconsistency in assessing the DFS70 pattern using the ANA-IIF test, specific assays should be used to confirm anti-DFS70 antibodies. The results of this study show that there is no difference in the overall diagnostic accuracy among methods that use the truncated or the full-length DFS70 antigenic sequence and that it is likely that antibodies directed against antigens other than DFS70 may be responsible for producing a DFS70-like ANA-IIF pattern.

Serological epitope profile of anti-Ro52-positive patients with systemic autoimmune rheumatic diseases.

BACKGROUND: Ro52 is an interferon-inducible protein of the tripartite motif family. Antibodies against Ro52 have been described in patients with different autoimmune diseases, such as systemic lupus erythematosus and Sjögren's syndrome, that are often associated with anti-Ro60 antibodies. The Ro52 autoantigen is extraordinarily immunogenic, and its autoantibodies are directed against both linear and conformational epitopes. The aim of this study was to evaluate the prevalence of antibodies to the five Ro52 domains, as well as to Ro52 176- to 196-amino acid (aa) and 200-239-aa peptides, in different systemic autoimmune rheumatic diseases (SARDs). We also aimed to verify whether antibodies to a single domain or domain association could increase their diagnostic specificity for any SARD. METHODS: Serum samples were obtained from 100 anti-Ro52 antibody-positive patients with SARDs and from 68 controls (50 healthy donors and 18 patients with other autoimmune or allergic diseases). A special line immunoassay was created containing a full-length Ro52 antigen expressed in insect cells using the baculovirus system, five recombinant Ro52 antigen fragments [Ro52-1, Ro52-2, Ro52-3, Ro52-4 (partly overlapping Ro52-1 and Ro52-2), and Ro52-5 (partly overlapping Ro52-2 and Ro52-3)], and two Ro52 peptides (176-196 aa and 200-239 aa), all expressed in Escherichia coli. RESULTS: In patients with SARDs, fragment prevalence rates were as follows: Ro52-1 = 3 %, Ro52-2 = 97 %, Ro52-3 = 0 %, Ro52-4 = 9 %, Ro52-5 = 28 %, Ro52 175-196-aa peptide = 6 %, and Ro52 200-239-aa peptide = 74 %. All control samples were negative for the full-length Ro52 and for the five fragments tested. CONCLUSIONS: The main epitope of the Ro52 antigen was localized on fragment 2 (aa 125-267), and the majority (97 %) of SARD sera had antibodies that target this fragment. As most of the samples were positive for fragment 2 and only some for fragments 4 or 5, which partially overlap fragment 2, it seems that the target epitope is localized in the middle of fragment 2 or in the area between fragments 4 and 5. No antibody against a single epitope or a combination of epitopes was linked to any of the single SARDs.

Specific chemoluminescence and immunoasdorption tests for anti-DFS70 antibodies avoid false positive results by indirect immunofluorescence.

OBJECTIVE: To evaluate two new diagnostic methods for the identification of anti-DFS70 antibodies in samples showing a DFS70-staining pattern by indirect immunofluorescence (IIF). METHODS: We studied 731 patients: 576 were collected consecutively among those that in the ANA test on HEp-2 cells had produced a DFS70 fluorescence pattern and 155 were a consecutive series of patients sent by referring physicians for routine ANA testing. As controls we studied 50 patients with autoimmune diseases and 120 patients with active infectious disease. All 731 sera were assayed for anti-DFS70 antibodies by a specific chemoluminescence assay (CLIA); 70 randomly selected IIF-positive sera and 35 samples from patients with autoimmune diseases were studied by inhibition tests using the HEp-2 Select method. RESULTS: Assays performed with the CLIA-DFS70 method were positive in 30.4% of the samples presenting a DFS70 pattern by IIF, in 1.3% of the routine ANA sera, in 1.6% of the infectious sera and in none of the 50 autoimmune controls. However, as the IIF-DFS70 positive group included 106 patients with systemic autoimmune rheumatic diseases (SARD), 11 of which were DFS70 positive by CLIA, the prevalence of DFS70 antibodies in SARD was 7.5%. The ANA test performed after the use of HEp-2 Select showed an inhibition in 95.7% of the sera. No change in fluorescence intensity and pattern morphology between the native sera and the same sera tested with the solution containing the DFS70 antigen was observed in the 35 samples from patients with autoimmune diseases. CONCLUSIONS: To avoid misinterpretation of ANA pattern and consequent diagnostic errors, confirmation of the DFS70-IIF pattern by CLIA or other specific methods is mandatory before reporting the presence of anti-DFS70 antibodies. The HEp-2 Select test in most cases eliminates the interference by anti-DFS70 antibodies and avoids the possible reporting of false positive results.

Establishment of the upper reference limit for thyroid peroxidase autoantibodies according to the guidelines proposed by the National Academy of Clinical Biochemistry: comparison of five different automated methods.

AIM OF THE STUDY: The estimation of the upper reference limit (URL) for autoantibodies against thyroid peroxidase (TPOAbs) is a controversial issue, because of an uncertainty associated with the criteria used to correctly define the reference population. In addition, the URL of TPOAbs is method-dependent and often arbitrarily established in current laboratory practice. The aim of this study was to determine the reference limits of TPOAbs in a male sample according to the National Academy of Clinical Biochemistry (NACB) guidelines, and to compare them with those obtained in a female group, for five third-generation commercial-automated immunoassay (IMA) platforms. METHODS: 120 healthy males and 120 healthy females with NACB-required characteristics (younger than 30 years, TSH between 0.5 and 2.0 mIU/L, normal thyroid ultrasound, absence of thyroid disease and absence of other autoimmune diseases) were studied. Sera were analyzed for TPOAbs concentration using five IMA methods applied in automated analyzers: Immulite 2000 XPi (IMM); Maglumi 2000 Plus (MAG); Kryptor Compact Plus (KRY); Phadia 250 (PHA) and Liaison XL (LIA). RESULTS: A statistically significant difference (p < 0.05) between medians in male and female groups was observed for PHA (2.6 and 3.1 IU/mL, respectively) but not for the other four methods. Scatter plots of TPOAbs values revealed a wide dispersion with very different coefficients of variation between the five methods, varying from 48.6 % for KRY in females to 126.3 % for MAG in females. The URLs differed in males and females according to the method: 28.7 and 29.0 IU/mL for IMM, 24.6 and 25.4 IU/mL for MAG, 6.4 and 6.9 IU/mL for KRY, 8.3 and 10.0 IU/mL for PHA and 14.2 and 17.9 IU/mL for LIA, respectively. Such URLs were lower than those stated by the manufacturers except for LIA in females. The difference between URLs ranged from a minimum of 11.3 % (LIA in males) to a maximum of 66.8 % (PHA in males). CONCLUSIONS: Differences in URLs could result from the different coating preparations of the TPO antigen (purified native or recombinant) on solid phase, which affect the proper exposure of the immunodominant epitopes recognized by the polyclonal antibodies present in serum of patients with autoimmune thyroid disease (AITD). Based on these findings, we suggest to overcome the proposal of the NACB guidelines which recommend to involve a single group of young male subjects, and propose, instead, to utilize two distinct groups: one of males and one of females. This new proposal removes the apparent contrast of an all-male reference group for a disease (such as AITD) that affects mainly females. However, in spite of the harmonization among methods provided by the use of an international standard preparation, the wide dispersion of quantitative results still observed in this study suggests the need for further efforts to better understand the cause of these discrepancies, focusing on TPO antigen preparations as the possible source of variability among different assays.

The Detection of Anti-adalimumab Antibodies in a Series of Inflammatory Polyarthritis: three ELISA Methods Compared.

BACKGROUND: A reliable identification of ADAb represents a fundamental tool in the followup of patients under treatment with anti-TNF drugs. OBJECTIVES: To compare three immunoenzymatic assays for anti-adalimumab antibodies (AAA) detection. METHODS: The study was performed in 40 patients with chronic inflammatory polyarthritis, comprising both patients showing a good response to adalimumab (ADL) and patients who lost response or did not respond to ADL, recently or in the past (retrospective study). Thus, sera were collected before ADL administration or well after ADL discontinuation. AAA were analysed by three different bridging ELISAs, following manufacturers' instructions. RESULTS: All methods disclosed negative results in responder patients and univocally recognized 11/31 (35.5%) AAA highpositive samples in non-responder patients, including several cases that had discontinued ADL for a long time (range 3-48 months). Among the overall non-responder patients, 10/31 (32.3%) disclosed concordant clear-cut AAA-negative results, while negative versus low-positive or borderline results were found in another ten non-responder patients, indicating slight differences in sensitivity between the methods, especially in patients who were analysed retrospectively. Methotrexate in combination therapy with ADL tended to be more frequent in AAA-negative, than in AAA-positive patients (52.6% vs. 25%; p=ns). CONCLUSIONS: The three bridging ELISA methods under study showed a good agreement and were able to identify uniquely the presence of high positive AAA, even after a long time since ADL discontinuation.

Anti-zinc transporter protein 8 autoantibodies significantly improve the diagnostic approach to type 1 diabetes: an Italian multicentre study on paediatric patients.

BACKGROUND AND AIM: Anti-ZnT8 antibodies (ZnT8A) were recently proposed as a new independent serological marker in Type 1 diabetes (T1D), leading to a significant improvement of the positive predictive value of autoantibody measurement in this setting. The aim of this retrospective multicentre study was to investigate ZnT8A as a complement to the current T1D autoantibody assays in a large cohort of paediatric Italian patients. METHODS: ZnT8A were assessed by ELISA in 213 T1DM paediatric patients referred to six different centres in North-East Italy. Fifty-four were analysed at disease onset, 79 within 4 years from diagnosis and 80 after 5 or more years from diagnosis. Retrospective data about islet cell autoantibodies (ICA), anti-insulin (IAA), anti-glutamate decarboxylase (GADA) and anti-protein tyrosine phosphatase IA-2 (IA-2A) antibodies were collected and compared. RESULTS: Overall, ZnT8A showed positive results in 106/213 (49.8 %) T1D patients and were found in 10 (4.7 %) subjects previously classified as autoantibody negative based on the existing markers (GADA, IA-2A, IAA and ICA), increasing the overall diagnostic sensitivity from 85.9 to 90.6 %. ZnT8A disclosed the same sensitivity (61.1 %) at disease onset as GADA (61.1 %) and higher than IA-2A (53.7 %), with only GADA showing much persistence in the long-term follow-up. Focusing on patients at disease onset, all the ICA positive were associated with at least one positive autoantibody among GADA, IA-2A and ZnT8A, 16.7 % of whom presenting only anti-ZnT8-positive antibodies. CONCLUSION: This study confirms ZnT8A as an important additional and independent diagnostic marker of T1D and supports its introduction in the routine diagnostic process to replace less sensitive methods and improve the overall autoantibody sensitivity.

High levels of soluble CTLA-4 are present in anti-mitochondrial antibody positive, but not in antibody negative patients with primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is a chronic autoimmune cholestatic liver disease frequently characterized by anti-mitochondrial autoantibodies (AMA). A minority of patients are AMA-negative. Cytotoxic-T-Lymphocyte-Antigen-4 (CTLA-4) is a surface molecule expressed on activated T-cells delivering a critical negative immunoregulatory signal. A soluble form of CTLA-4 (sCTLA-4) has been detected at high concentrations in several autoimmune diseases, and its possible functional meaning has been suggested. We aimed to evaluate sCTLA-4 concentration in sera of patients with PBC and to correlate it to immunological abnormalities associated with the disease. Blood samples were collected from 82 PBC-patients diagnosed according to international criteria (44 AMA-positive/MIT3-positive and 38 AMA-negative-MIT3-negative), and 65 controls. sCTLA-4 levels were evaluated by ELISA and Western blot. Increased sCTLA-4 concentrations were found in all AMA-positive PBC-patients, but in none of the AMA-negative ones, nor in normal controls or in controls with unrelated liver diseases. sCTLA-4 presence was associated with autoantibodies against MIT3, but not with nuclear autoantibodies (sp100, gp210). This is the first study to demonstrate that levels of sCTLA-4 are elevated in sera of PBC patients. However, they are clearly restricted to patients with AMA positivity, suggesting an immunological difference with respect to AMA-negative ones.

Anti-DFS70 antibodies: a useful biomarker in a pediatric case with suspected autoimmune disease.

Antidense fine speckles 70 (anti-DFS70) antibodies, a peculiar antinuclear antibody (ANA) pattern by indirect immunofluorescence, is frequently observed in ANA-positive individuals with no evidence of systemic autoimmune rheumatic disease. They may be found in many different inflammatory conditions and in healthy individuals. We herein report a case of an 8-year-old girl presenting with generalized edema, hypertension, hepatomegaly, and a history of pharyngitis, which occurred 3 weeks earlier. Laboratory analysis revealed low complement C3 (6 mg/dL), microhematuria, and proteinuria. A diagnosis of acute glomerulonephritis was made. Anti-dsDNA, antiextractable nuclear antigens, and antineutrophil cytoplasmic antibodies were negative. However, a highly positive (1:640) ANA immunofluorescence test with dense fine speckles pattern was found. The presence of anti-DFS70 immunoglobulin G antibodies was confirmed by a specific immunoassay. In conclusion, the presence of isolated anti-DFS70 antibodies may be useful to exclude an autoimmune pathogenesis in those children with a positive ANA test and a clinical picture possibly attributable to systemic autoimmune rheumatic disease. This will avoid further unnecessary investigation with the potential for incorrect diagnosis and possibly harmful treatment.

Introduction of gluten, HLA status, and the risk of celiac disease in children.

BACKGROUND: The relationship between the risk of celiac disease and both the age at which gluten is introduced to a child's diet and a child's early dietary pattern is unclear. METHODS: We randomly assigned 832 newborns who had a first-degree relative with celiac disease to the introduction of dietary gluten at 6 months (group A) or 12 months (group B). The HLA genotype was determined at 15 months of age, and serologic screening for celiac disease was evaluated at 15, 24, and 36 months and at 5, 8, and 10 years. Patients with positive serologic findings underwent intestinal biopsies. The primary outcome was the prevalence of celiac disease autoimmunity and of overt celiac disease among the children at 5 years of age. RESULTS: Of the 707 participants who remained in the trial at 36 months, 553 had a standard-risk or high-risk HLA genotype and completed the study. At 2 years of age, significantly higher proportions of children in group A than in group B had celiac disease autoimmunity (16% vs. 7%, P=0.002) and overt celiac disease (12% vs. 5%, P=0.01). At 5 years of age, the between-group differences were no longer significant for autoimmunity (21% in group A and 20% in group B, P=0.59) or overt disease (16% and 16%, P=0.78 by the log-rank test). At 10 years, the risk of celiac disease autoimmunity was far higher among children with high-risk HLA than among those with standard-risk HLA (38% vs. 19%, P=0.001), as was the risk of overt celiac disease (26% vs. 16%, P=0.05). Other variables, including breast-feeding, were not associated with the development of celiac disease. CONCLUSIONS: Neither the delayed introduction of gluten nor breast-feeding modified the risk of celiac disease among at-risk infants, although the later introduction of gluten was associated with a delayed onset of disease. A high-risk HLA genotype was an important predictor of disease. (Funded by the Fondazione Celiachia of the Italian Society for Celiac Disease; CELIPREV ClinicalTrials.gov number, NCT00639444.).

Diagnosis and classification of celiac disease and gluten sensitivity.

Celiac disease is a complex disorder, the development of which is controlled by a combination of genetic (HLA alleles) and environmental (gluten ingestion) factors. New diagnostic guidelines developed by ESPGHAN emphasize the crucial role of serological tests in the diagnostic process of symptomatic subjects, and of the detection of HLA DQ2/DQ8 alleles in defining a diagnosis in asymptomatic subjects belonging to at-risk groups. The serological diagnosis of CD is based on the detection of class IgA anti-tissue transglutaminase (anti-tTG) and anti-endomysial antibodies. In patients with IgA deficiency, anti-tTG or anti-deamidated gliadin peptide antibody assays of the IgG class are used. When anti-tTG antibody levels are very high, antibody specificity is absolute and CD can be diagnosed without performing a duodenum biopsy. Non-celiac gluten sensitivity is a gluten reaction in which both allergic and autoimmune mechanisms have been ruled out. Diagnostic criteria include the presence of symptoms similar to those of celiac or allergic patients; negative allergological tests and absence of anti-tTG and EMA antibodies; normal duodenal histology; evidence of disappearance of the symptoms with a gluten-free diet; relapse of the symptoms when gluten is reintroduced.

Automated antinuclear immunofluorescence antibody screening: a comparative study of six computer-aided diagnostic systems.

BACKGROUND: Indirect immunofluorescence (IIF) plays an important role in immunological assays for detecting and measuring autoantibodies. However, the method is burdened by some unfavorable features: the need for expert morphologists, the subjectivity of interpretation, and a low degree of standardization and automation. Following the recent statement by the American College of Rheumatology that the IIF technique should be considered as the standard screening method for the detection of anti-nuclear antibodies (ANA), the biomedical industry has developed technological solutions which might significantly improve automation of the procedure, not only in the preparation of substrates and slides, but also in microscope reading. METHODS: We collected 104 ANA-positive sera from patients with a confirmed clinical diagnosis of autoimmune disease and 40 ANA-negative sera from healthy blood donors. One aliquot of each serum, without information about pattern and titer, was sent to six laboratories of our group, where the sera were tested with the IIF manual method provided by each of the six manufacturers of automatic systems. Assignment of result (pos/neg), of pattern and titer was made by consensus at a meeting attended by all members of the research team. Result was assigned if consensus for pos/neg was reached by at least four of six certifiers, while for the pattern and for the titer, the value observed with higher frequency (mode) was adopted. Seventeen ANA-positive sera and six ANA-negative sera were excluded. Therefore, the study with the following automatic instrumentation was conducted on 92 ANA-positive sera and on 34 ANA-negative sera: Aklides, EUROPattern, G-Sight (I-Sight-IFA), Helios, Image Navigator, and Nova View. Analytical imprecision was measured in five aliquots of the same serum, randomly added to the sample series. RESULTS: Overall sensitivity of the six automated systems was 96.7% and overall specificity was 89.2%. Most false negatives were recorded for cytoplasmic patterns, whereas among nuclear patterns those with a low level of fluorescence (i.e., multiple nuclear dots, midbody, nuclear rim) were sometimes missed. The intensity values of the light signal of various instruments showed a good correlation with the titer obtained by manual reading (Spearman's rho between 0.672 and 0.839; P<0.0001 for all the systems). Imprecision ranged from 1.99% to 25.2% and, for all the systems, it was lower than that obtained by the manual IIF test (39.1%). The accuracy of pattern recognition, which is for now restricted to the most typical patterns (homogeneous, speckled, nucleolar, centromere, multiple nuclear dots and cytoplasmic) was limited, ranging from 52% to 79%. CONCLUSIONS: This study, which is the first to compare the diagnostic accuracy of six systems for automated ANA-IIF reading on the same series of sera, showed that all systems are able to perform very well the task for which they were created. Indeed, cumulative automatic discrimination between positive and negative samples had 95% accuracy. All the manufacturers are actively continuing the development of new and more sophisticated software for a better definition in automatic recognition of patterns and light signal conversion in end-point titer. In the future, this may avert the need for serum dilution for titration, which will be a great advantage in economic terms and time-saving.

The introduction of anti-phosphatidylserine/prothrombin autoantibodies in the laboratory diagnostic process of anti-phospholipid antibody syndrome: 6 months of observation.

PURPOSE: To evaluate the impact of the introduction of the anti-phosphatidylserine/prothrombin autoantibodies (aPS/PT) in the laboratory diagnostic process of anti-phospholipid antibody syndrome (APS). METHODS: Four hundred and twenty-one patients (71.5 % females; 53 ± 15 years) presenting a medical prescription for aPS/PT antibodies were consecutively enrolled in the study from March 2013 to August 2013. During the same period, aPS/PT were additionally investigated in a selected series of 62 patients characterized by difficult lupus anticoagulant (LA) tests interpretation and in a retrospective series of 52 LA positive cases with available data about anti-prothrombin (aPT) antibodies. The aPS/PT antibodies, as well as the anti-cardiolipin (aCL), the anti-ß2 glycoprotein I (aß2GPI) and the aPT antibodies were analyzed by ELISA. LA was tested according to the recommended criteria, performing both the screen and the confirm steps. RESULTS: Overall, aPS/PT IgM positive (>30 U/ml) and/or IgG frankly positive (>40 U/ml) antibodies were found in 49/421 (11.6 %) cases. Among the LA positive patients, we found 56.1 % aPS/PT positive versus 31.7 % aCL and/or aß2GPI positive cases, with limited (17.1 %) simultaneous positivity. The PS/PT complex resulted the newly recognized specificity in about 27 % of patients recruited from the subset with difficult LA test interpretation. Compared to aPT antibodies, the aPS/PT antibodies displayed a much higher sensitivity (55.8 versus 15.4 %) in LA positive patients. CONCLUSIONS: The introduction of aPS/PT antibodies in the diagnostic process of APS is highly recommended, since they disclose a notable diagnostic performance and a high correlation with LA activity, such that they can be a viable alternative.

The TTTT B lymphocyte stimulator promoter haplotype is associated with good response to rituximab therapy in seropositive rheumatoid arthritis resistant to tumor necrosis factor blockers.

OBJECTIVE: To investigate the polymorphisms in the promoter region of the B lymphocyte stimulator (BLyS) gene as markers of response to rituximab (RTX) in rheumatoid arthritis (RA). METHODS: The study was first conducted in 152 Italian RA patients and then replicated in an additional 117 RA patients (73 Italian, 44 British). The European League Against Rheumatism response criteria were used to evaluate the response rate at months 4 and 6 after the first cycle of RTX, by means of the Disease Activity Score in 28 joints using the erythrocyte sedimentation rate; patients were classified according to the best response shown between months 4 and 6. BLyS promoter polymorphisms were analyzed by polymerase chain reaction followed by the analysis of the restriction fragments, BLyS promoter haplotypes were analyzed using the expectation-maximization algorithm, and BLyS serum levels were analyzed using enzyme-linked immunosorbent assay. Odds ratios (ORs) were calculated with 95% confidence intervals (95% CIs). RESULTS: The TTTT BLyS promoter haplotype appeared to be significantly associated with response to RTX only in the subset of seropositive patients (those positive for rheumatoid factor and/or anti-cyclic citrullinated peptide). The replication study confirmed that this association was limited to seropositive RA patients in whom treatment with anti-tumor necrosis factor (anti-TNF) agents had previously failed. In the whole series of seropositive patients in whom anti-TNF agents had previously failed, patients carrying the TTTT BLyS promoter haplotype were more prevalent in good responders (18 of 43 [41.9%]) than in moderate responders (20 of 83 [24.1%]) or in nonresponders (1 of 21 [4.8%]) (for good responders versus nonresponders, OR 14.4 [95% CI 1.77-117.39], P=0.0028). Furthermore, multivariate analysis selected the TTTT BLyS promoter haplotype as an independent marker of good response to RTX (for good responders versus nonresponders, OR 16.2 [95% CI 1.7-152.5], P=0.01; for good responders versus moderate responders and nonresponders combined, OR 3.1 [95% CI 1.2-7.8], P=0.02). The relationship between BLyS polymorphisms and BLyS serum levels remained unclear. CONCLUSION: BLyS promoter genotyping may be suitable for identifying seropositive RA patients who may have a good response to RTX after anti-TNF agents have failed.

Clinical usefulness of the serological gastric biopsy for the diagnosis of chronic autoimmune gastritis.

AIM: To assess the predictive value for chronic autoimmune gastritis (AIG) of the combined assay of anti-parietal-cell antibodies (PCA), anti-intrinsic-factor antibodies (IFA), anti-Helicobacter pylori (Hp) antibodies, and measurement of blood gastrin. METHODS: We studied 181 consecutive patients with anemia, due to iron deficiency resistant to oral replacement therapy or to vitamin B12 deficiency. RESULTS: 83 patients (45.8%) tested positive for PCA and underwent gastroscopy with multiple gastric biopsies. On the basis of the histological diagnosis, PCA-positive patients were divided into 4 groups: (1) 30 patients with chronic atrophic gastritis; they had high concentrations of PCA and gastrin and no detectable IFA; (2) 14 subjects with metaplastic gastric atrophy; they had high PCA, IFA, and gastrin; (3) 18 patients with nonspecific lymphocytic inflammation with increased PCA, normal gastrin levels, and absence of IFA; (4) 21 patients with multifocal atrophic gastritis with "borderline" PCA, normal gastrin, absence of IFA and presence of anti-Hp in 100% of the cases. CONCLUSIONS: The assay of four serological markers proved particularly effective in the diagnostic classification of gastritis and highly correlated with the histological profile. As such, this laboratory diagnostic profile may be considered an authentic "serological biopsy."