Diagnostic accuracy of antiendomysial antibodies biopsy test for celiac disease in clinical practice.

BACKGROUND: The diagnosis of celiac disease (CD) is still challenging and tests that show an activation of the immune system against gluten are required. IgA antiendomysial antibodies detection in the supernatant of intestinal biopsies by immunofluorescence technique (AEA-biopsy) is a promising diagnostic tool. The aim of the present study was to evaluate the diagnostic accuracy of AEA-biopsy in a pediatric population with suspected CD. METHODS: All children who underwent upper gastrointestinal endoscopy at the Unit of Pediatrics of Treviso Hospital were enrolled and divided into 4 groups: classical CD, CD excluded, potential CD and control group. For each patient, serum autoantibodies and histological evaluation were determined. Two additional biopsy samples were taken to test for presence of AEA. RESULTS: A total of 92 patients were enrolled. All the classical CD cases (38) had a positive AEA-biopsy. In the CD excluded group (10 in total) AEA-biopsy was negative in all patients except 1. Among potential CD patients (which were 14), AEA-biopsy was negative in 4. In the control group (30 patients) AEA-biopsy was negative in all patients except 1. The sensitivity and specificity of AEA-biopsy were 100% and 96% respectively. CONCLUSIONS: AEA-biopsy has an excellent diagnostic accuracy in a routine clinical setting.

Hb Alessandria [ß37(C3)Trp→Leu; HBB: c.113G>T]: a Novel Variant on the ß-Globin Chain with Slightly Increased Affinity for Oxygen Detected by Capillary Electrophoresis.

We report a novel mutation on the ß-globin gene in a 68-year-old woman of Sicilian origin living in Alessandria, Italy. This mutation produces a hemoglobin (Hb) variant of Hb A that was detected by the capillary electrophoresis (CE) method during measurement of Hb A1c. The variant Hb did not separate from Hb A using different high performance liquid chromatography (HPLC) instruments. Direct DNA sequencing revealed a G>T transversion at codon 37 and subsequent substitution of a tryptophan residue for a leucine residue. The new Hb variant was named Hb Alessandria [ß37(C3)Trp→Leu; HBB: c.113G>T]. The p50 value was slightly decreased while the stability test at 37 °C in isopropyl alcohol and the main erythrocyte parameters were normal. Overall, the patient appeared clinically normal.

Impact of Hypogammaglobulinemia on the Course of COVID-19 in a Non-Intensive Care Setting: A Single-Center Retrospective Cohort Study.

Background: Severity and mortality of COVID-19 largely depends on the ability of the immune system to clear the virus. Among various comorbidities potentially impacting on this process, the weight and the consequences of an antibody deficiency have not yet been clarified. Methods: We used serum protein electrophoresis to screen for hypogammaglobulinemia in a cohort of consecutive adult patients with COVID-19 pneumonia, hospitalized in non-intensive care setting between December 2020 and January 2021. The disease severity, measured by a validated score and by the need for semi intensive (sICU) or intensive care unit (ICU) admission, and the 30-day mortality was compared between patients presenting hypogammaglobulinemia (HYPO) and without hypogammaglobulinemia (no-HYPO). Demographics, comorbidities, COVID-19 specific treatment during the hospital stay, disease duration, complications and laboratory parameters were also evaluated in both groups. Results: We enrolled 374 patients, of which 39 represented the HYPO cohort (10.4%). In 10/39 the condition was previously neglected, while in the other 29/39 hematologic malignancies were common (61.5%); 2/39 were on regular immunoglobulin replacement therapy (IgRT). Patients belonging to the HYPO group more frequently developed a severe COVID-19 and more often required sICU/ICU admission than no-HYPO patients. IgRT were administered in 8/39 during hospitalization; none of them died or needed sICU/ICU. Among HYPO cohort, we observed a significantly higher prevalence of neoplastic affections, of active oncologic treatment and bronchiectasis, together with higher prevalence of viral and bacterial superinfections, mechanical ventilation, convalescent plasma and SARS-CoV-2 monoclonal antibodies administration during hospital stay, and longer disease duration. Multivariate logistic regression analysis and Cox proportional hazard regression confirmed the impact of hypogammaglobulinemia on the COVID-19 severity and the probability of sICU/ICU admission. The analysis of the mortality rate in the whole cohort showed no significant difference between HYPO and no-HYPO. Conclusions: Hypogammaglobulinemia, regardless of its cause, in COVID-19 patients hospitalized in a non-intensive care setting was associated to a more severe disease course and more frequent admission to s-ICU/ICU, particularly in absence of IgRT. Our findings emphasize the add-value of routine serum protein electrophoresis evaluation in patients admitted with COVID-19 to support clinicians in patient care and to consider IgRT initiation during hospitalization.

Two co-inherited hemoglobin variants revealed by capillary electrophoresis during quantification of glycated hemoglobin.

OBJECTIVES: The observation of numerous new structural defects in hemoglobin (Hb) has often been linked to the evolution and development of device technologies used for the separation and quantification of hemoglobin components. However, the increased use of preventive tests for hemoglobinopathies and separative methods to quantify glycated hemoglobin (HbA1c) also contributed to these observations, as demonstrated by the case described here. Our aim is to emphasize that different separative method can provide more useful information in patient management. METHODS: A 64-year-old diabetic woman of Moroccan descent was examined in the context of HbA1c monitoring. The test was performed using high performance liquid chromatography (HPLC) and capillary electrophoresis (CE) systems. Molecular characterization was performed by direct sequencing of the ß and α globin genes. RESULTS: The two methods used showed the presence of an anomalous fraction identified as HbS, already observed previously, but only through CE it was possible to observe the presence of another variant and its hybrid components. Direct sequencing of ß and α globin genes confirmed heterozygous HbS [ß6 (A3) Glu→Val; HBB: c.20A>T] and allowed to identify a mutation on the α2, [α114 (GH2) Pro→Leu gene; HBA2: c.344C>T] corresponding to the rare Hb Nouakchott variant. CONCLUSIONS: The two Hb variants highlighted by the EC and the molecular characterization therefore allowed adequate advice, the correct assessment of HbA1c and metabolic status and therefore better clinical management of the patient. The availability of different instruments in the same laboratory, confirming situations of diagnostic uncertainty, represents a valuable opportunity that should be encouraged.

Hemoglobin A2 and Heterogeneous Diagnostic Relevance Observed in Eight New Variants of the Delta Globin Gene.

BACKGROUND: Hemoglobin A (Hb A) (α2ß2) in the normal adult subject constitutes 96-98% of hemoglobin, and Hb F is normally less than 1%, while for hemoglobin A2 (Hb A2) (α2δ2), the normal reference values are between 2.0 and 3.3%. It is important to evaluate the presence of possible delta gene mutations in a population at high risk for globin gene defects in order to correctly diagnose the ß-thalassemia carrier. METHODS: The most used methods for the quantification of Hb A2 are based on automated high performance liquid chromatography (HPLC) or capillary electrophoresis (CE). In particular Hb analyses were performed by HPLC on three dedicated devices. DNA analyses were performed according to local standard protocols. RESULTS: Here, we described eight new δ-globin gene variants discovered and characterized in some laboratories in Northern Italy in recent years. These new variants were added to the many already known Hb A2 variants that were found with an estimated frequency of about 1-2% during the screening tests in our laboratories. CONCLUSIONS: The knowledge recognition of the delta variant on Hb analysis and accurate molecular characterization is crucial to provide an accurate definitive thalassemia diagnosis, particularly in young subjects who would like to ask for a prenatal diagnosis or preimplantation genetic diagnosis.

Hemoglobin Yamagata [ß132(H10)Lys→Asn; (HBB: c.399A>T)]: a mosaic to be put together.

OBJECTIVES: Artifactually altered glycated hemoglobin (HbA1c) concentrations are frequently linked to hemoglobin (Hb) variants. Their expression and detection require in-depth analysis. METHODS: Cation exchange high performance liquid chromatography (HPLC) (Bio-Rad Variant™ II; Trinity Biotech Premier Hb9210 Resolution), capillary electrophoresis (CE) (Sebia Capillarys 2 Flex Piercing) and mass spectrometry (MS) (Waters) were used for variant detection; Sanger sequencing, multiplex ligation-dependent probe amplification (MLPA) and next generation sequencing (NGS) were used for DNA analysis; HbA1c was measured with cation exchange HPLC (Bio-Rad Variant™ II; Arkray Adams HA-8180V; Tosoh HLC-723 G7), CE (Sebia Capillarys 2 Flex Piercing), boronate affinity HPLC (Trinity Biotech Hb9210 Premier), immunoassay (Cobas c501 Tina-quant HbA1c Gen. 3; Nihon Kohden CHM-4100 Celltac chemi HbA1c HA-411V) and enzymatic assay (Abbott Architect c 8000 HbA1c). RESULTS: Hb Yamagata [ß132(H10)Lys→Asn; (HBB: c.399A>T)] was identified in the proband by MS after the observation of an abnormal peak in HPLC and CE. A mosaic expression of this variant was detected by NGS (mutant: 8%; wild type: 92%), after negative results in Sanger sequencing. Hb Yamagata interfered with HbA1c measurements by cation exchange HPLC and CE whereas immuno and enzymatic assay values showed good agreement with boronate affinity HPLC measurement. CONCLUSIONS: A mosaicism of Hb Yamagata was found in a patient with altered HbA1c values. This rare gene variant was detected only by advanced technologies as MS and NGS. The variant interfered with common HbA1c determination methods.

Hb A2-Pistoia [δ89(F5)Ser→Asn, HBD: c.269G>a]: a Novel Mutation on the δ-Globin Gene in an Italian Child.

We describe a new hemoglobin (Hb) variant, found in a 6-year-old Italian male living in Pistoia, Italy. An abnormal pattern compatible with a Hb A2 variant was observed on capillary electrophoresis (CE); direct sequencing revealed a transition at codon 89 of the δ gene (HBD: c.269G>A) changing serine into asparagine. The variant was also identified as Hb A2-Pistoia according to the traditional nomenclature and no other globin defect was present. The observation and description of this Hb A2 variant contributes to the number and heterogeneity of mutations of the δ-globin gene in the Mediterranean Area.

A new diagnostic algorithm for pattern-oriented autoantibody testing according to the ICAP nomenclature: A pilot study.

The commercial tests currently available as second-level tests to detect ANA sub-specificities are generally used independently from the ANA immunofluorescence (IIF) pattern. The aim of this study was to evaluate the efficacy of the use of a customizable pattern-oriented antigenic panel by immunoblot (IB) using the International Consensus on ANA Patterns (ICAP) classification scheme, in order to introduce a novel and updated autoimmune diagnostic flowchart. 710 sera referred for routine ANA testing were selected on the basis of the ANA pattern according to the ICAP nomenclature (nuclear speckled AC-2,4,5; nucleolar AC-8,9,10,29; cytoplasmic speckled AC-18,19,20) and on an IIF titer ≥1:320. They were then assayed by three experimental IB assays using a panel of selected antigens. ICAP-oriented IB detected 515 antibody reactivities vs. 457 of traditional anti-ENA in the nuclear speckled pattern group, 108 vs. 28 in the nucleolar pattern group, and 43 vs. 34 in the cytoplasmic speckled pattern. This pilot study may lead the way for a new approach introducing an ICAP pattern-oriented follow up testing as a valid alternative to the existing standard panels, thus enabling more patients with autoimmune rheumatic disease to be accurately diagnosed.

A new M23-based ELISA assay for anti-aquaporin 4 autoantibodies: diagnostic accuracy and clinical correlation.

PURPOSE: Although many assays have been developed to detect anti-aquaporin-4 (AQP4) antibodies, most of these assays require sophisticated techniques and are thus only available at specialized laboratories. The aim of this study was to evaluate the analytical and clinical performance of a new commercial enzyme-linked immunosorbent assay (ELISA RSR, AQP4 Ab Version 2) to detect anti-AQP4 antibodies performed on a fully automated system (SkyLAB 752). METHODS: Serum samples from 64 patients with neuromyelitis optica spectrum disorders (NMOSD) (including NMO, longitudinally extensive myelitis-LETM, optical neuritis and myelitis) and 27 controls were tested for anti-AQP4 antibodies. All sera were previously tested using an indirect immunofluorescence (IIF) method on primate tissue, as the reference method. Commercial control sera were used to determine within-run, between-day and within-laboratory precision (CLSI guidelines). RESULTS: At a cut-off value of 2.1 U/mL as determined by ROC curves, sensitivity and specificity for NMO were 83.3% and 100%, respectively. The ELISA assay provided 100% concordant results with the reference IIF method. The median concentration of anti-AQP4 antibodies was statistically higher in patients with NMO than in patients with LETM (p = 0.0006) or with other NMOSD and in controls (p < 0.0001). At the concentration of 12.4 and 28.1 U/mL, the within-run, between-day and within-laboratory coefficients of variation (CV) were 3.2% and 3%, 7.6% and 7.4%, and 8.2% and 8.0%, respectively. CONCLUSIONS: This new ELISA method performed on a fully automated system, showed high sensitivity and absolute specificity, good CV in precision tests, and provided observer-independent quantitative results.

Anti-rods/rings autoantibody seropositivity does not affect response to telaprevir treatment for chronic hepatitis C infection.

PURPOSE: Autoantibodies to intracellular 'rods and rings' structures (anti-rods/rings or anti-RR) are strongly associated with hepatitis C (HCV) patients treated with interferon-α/ribavirin (IFN/RBV) and are linked with non-responsiveness to IFN/RBV or relapse, especially in Italian patients. This is the first study to determine whether there is any correlation of anti-RR with non-responsiveness to IFN/RBV treatment in patients also treated with telaprevir (TPV), one of several new therapies for chronic HCV recently implemented. METHODS: From 2013 to 2014, 52 HCV-infected patients were treated with IFN/RBV and TPV at five Italian clinics. Patient sera were collected and analyzed by indirect immunofluorescence for the presence of anti-RR antibodies. Patients were classified as anti-RR positive or anti-RR negative, and then various biological and clinical variables were analyzed to compare the two groups, including gender, age, HCV genotype, previous IFN/RBV treatment, and IFN/RBV/TPV treatment outcome. RESULTS: Of these 52 HCV patients treated with IFN/RBV/TPV, 10/32 (31%) who previously received IFN/RBV were anti-RR positive, compared to 0 of 20 treatment-naïve patients. Anti-RR-positive patients relapsed more than anti-RR-negative patients (3/10, 30% vs. 2/42, 5%; p < 0.05). However, zero anti-RR-positive patients were non-responsive, and frequencies of sustained virological response were similar (anti-RR positive: 7/10, 70% vs. anti-RR negative: 33/42, 79%). CONCLUSIONS: Overall, the data suggest that anti-RR seropositivity is not associated with resistance to TPV treatment in this patient cohort, but monitoring anti-RR-positive patients for relapse within the first 6 months after treatment may be useful.

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.

Autoantibody Profiling in a Cohort of Pediatric and Adult Patients With Autoimmune Hepatitis.

BACKGROUND: Autoimmune hepatitis (AIH) is a rare condition characterized by the presence of autoantibodies distinctive of type 1 AIH (AIH-1) and type 2 AIH (AIH-2). The aim of this study was to evaluate the autoantibody profile in a cohort of pediatric and adult AIH patients, using both indirect immunofluorescence (IIF) and a new multiplexed line-blot assay. METHODS: Sera from 63 pediatric and 53 adult AIH patients were tested for antinuclear (ANA), antismooth muscle (SMA), anti-liver kidney microsome 1 (anti-LKM1), anti-liver cytosol 1 (anti-LC1) autoantibodies using IIF methods; for anti-LKM1, anti-LC1, and soluble liver antigen/liver-pancreas (anti-SLA/LP) autoantibodies using the line-blot; for anti-F-actin autoantibodies using IIF both on VSM47 cell-line and on rat intestinal epithelial cells. RESULTS: AIH-1 was the most common type of AIH in the adult cohort (73.6%), while AIH-2 was the most common AIH in the pediatric cohort (61.9%). Both in adult and pediatric AIH-2 anti-LKM1 were the prevalent autoantibodies. In pediatric AIH-2 anti-LC1 autoantibodies were more frequent than in adult AIH-2 (59 vs. 28.6%), and in 35.9% of cases they were present alone. In 17 patients anti-LC1 autoantibodies were detected only with the line-blot assay. The levels of anti-LKM1 and of anti-LC1 were not different between adult and pediatric AIH, and the overall agreement between the results obtained with the two IIF methods for F-actin detection was 98.8% (CI 95%: 94.4-99.7%). CONCLUSIONS: The line-blot assay showed a higher sensitivity than IIF for anti-LC1 detection. Anti-LKM1 and anti-LC1 autoantibody levels are not different in adults and children. An almost perfect agreement between the two IIF methods for anti-F-actin detection has been observed.

Autoantibody profiling of patients with primary biliary cirrhosis using a multiplexed line-blot assay.

OBJECTIVE: To evaluate the autoantibody profile in patients with primary biliary cirrhosis (PBC) using a new multiplexed line-blot assay specifically designed for the diagnosis of autoimmune liver diseases. METHODS: Sera of 58 consecutive PBC patients and 191 disease controls (144 with autoimmune liver diseases other than PBC, and 67 with non-autoimmune chronic liver diseases) were tested by both the multiplexed line-blot Autoimmune Liver Disease Profile 2 (ALD2) and by IIF on HEp-2 cells and on rat kidney/liver/stomach tissues. ALD2 contains the following PBC-associated antigens: AMA-M2, natively purified from bovine heart; M2-E3, a recombinant fusion protein including the E2 subunits of PDC, BCOADC and OGDC; sp100, PML and gp210 recombinant proteins. RESULTS: With the ALD2 assay, a positive reaction to AMA-M2, M2-E3, sp100, PML and gp210 in PBC patients was observed in 77.6%, 84.5%, 34.5%, 15.1% and 18.9%, respectively, of the PBC sera. The overall sensitivity and specificity for PBC were 98.3% and 93.7%. Using IIF, positivity rates to AMA, and to antinuclear autoantibodies with membranous/rim-like and multiple nuclear dot patterns were 86.2%, 8.6% and 22.4%, respectively. The overall sensitivity and specificity for PBC of the IIF method were 86.2% and 97.9%, respectively. CONCLUSIONS: The ALD2 line-blot showed a good diagnostic accuracy for PBC and a higher sensitivity than the IIF method to detect sp100 and gp210 autoantibodies.

[Goodpasture's disease: a case series]. / La Malattia di Goodpasture: l'esperienza di un singolo centro.

Goodpasture's disease (GD) is an uncommon and severe autoimmune disorder caused by circulating autoantibodies directed against the glomerular basement membrane cross-reacting with the alveolar basement membrane. GD is clinically characterized by rapidly progressive glomerulonephritis, often associated with pulmonary hemorrhage representing a nephrological emergency. We present the clinical features of 9 cases, diagnosed in 1997-2012, in our Renal Unit. Contrary to previous reports, we found a predominance of GD in females and we observed unusual clinical patterns, such as the association with renal vein thrombosis in a pregnant patient, thrombosis of the pulmonary arteries and a late isolated recurrence of alveolitis. In dialysis-dependent patients, renal transplantation can represent an available treatment option.

An IgE multiple myeloma: contradictory findings in clinical laboratory testing.

BACKGROUND: IgE multiple myeloma is a rare kind of plasma cell disorder, characterized by an aggressive clinical course, where laboratory testing plays a fundamental role for the correct diagnosis in order to start a targeted therapy. In the present paper it is described a case of IgE myeloma where contradictory findings between immunometric and separative techniques were found. MATERIALS AND METHODS: Serum and 24h urine samples were tested using electrophoresis and immunofixation electrophoresis employing IgE antiserum and IgE were quantified using an immunometric method. RESULTS: Serum immunofixation evidenced a monoclonal band ascribable to IgE lambda and IgE serum concentration was 1,364,00 kU/L. Urine electrophoresis evidenced a band compatible with IgE, and urine concentration was 2715 kU/L. On the contrary in the immunofixation of the urine sample no band reacting with IgE antiserum was found. CONCLUSIONS: Considering that the immunometric method measured IgE in urine sample and the electrophoresis of urine sample evidenced a band compatible with IgE, the explanation could be that during renal filtration or because of some characteristics related to urine matrix, the immunoglobulin IgE could had been modified in the site recognized by the antiserum used in immunofixation, and not in the one used in the immunometric method.

Hb Treviso [α91(FG3)Leu→Phe (α2)]: a new slightly unstable hemoglobin variant with moderately decreased oxygen affinity.

We report a new hemoglobin (Hb) variant, found in a North-East Italian family living in the city of Treviso. The proband, a non anemic 60-year-old male with a history of chronic rhinitis, allergy to Parietaria and suspected obstructive sleep apnea syndrome, was referred for blood gas analysis. Determination of the oxygen affinity revealed a p50 of 32.5 mmHg (control 27.5 mmHg) indicating a moderate decrease in oxygen affinity. An abnormal pattern compatible with an α Hb variant was observed on high performance liquid chromatography (HPLC); direct sequencing revealed a transition at codon 91 of the α2 gene (HBA2: c.274C>T) changing leucine into phenylalanine. Characterization and phenotype studies are reported.