OBJECTIVES:Despite numerous pieces of evidence of its important role as a diagnostic and prognostic biomarker in infectious diseases and sepsis, adrenomedullin (ADM) was only poorly investigated in cerebrospinal fluid (CSF) in central nervous system (CNS) infections. In this multicentre retrospective study, we investigated ADM CSF concentrations in acute meningitis compared to other noninfectious neurological disorders. METHODS:Since ADM is rapidly metabolised in vivo, the available diagnostic methods are designed to measure its cognate metabolite called mid-regional proADM (MR-proADM). We collected detailed clinical and laboratory data about 293 patients in whom MR-proADM was measured in CSF and plasma as part of the diagnostic workup. RESULTS:Patients were finally classified in CNS infection (n = 59), other CNS disorders (n = 190) and 14 disease controls, in which CNS infections and other definite disorders were excluded. Both cerebrospinal MR-proADM levels and their CSF/blood ratio were significantly higher in CNS infections compared to the other two groups (p < 0.001 and p < 0.037 respectively). CSF MR-proADM resulted informative for patients' classification, furnishing a volume under the ROC surface of 0.513 [0.414-0.613], overcoming the 1/6 threshold value for undecidability. Threshold values of < 0.807 and > 1.590 nmol/L can differentiate controls from neurological disorders and neurological disorders from CNS infections respectively. CONCLUSIONS:We demonstrated significant upregulation of Adrenomedullin in CSF during infections compared to other neurological diseases and proposed preliminary thresholds of CSF MR-proADM to be used in the diagnostic workup of acute CNS infections, to help with differential diagnosis and possibly guide targeted therapeutic interventions.

BACKGROUND:Adrenomedullin (ADM) is a potent hormone-like peptide rapidly induced by hypoxia and inflammatory cytokines in the early stages of sepsis. For this reason, the dosage of its more stable precursor fragment called mid-regional (MR)-proADM is currently recommended to assist in triaging patients in the emergency department. Since MR-proADM dosage is currently only approved for use in plasma, we validated its dosage in cerebrospinal fluid (CSF) samples to improve the diagnosis of central nervous system (CNS) diseases. METHODS:MR-proADM concentrations were measured in samples using a fully automated platform (Brahms Kryptor Gold Analyzer, Thermo Scientific, Germany), applying the same analytical conditions in plasma and CSF samples, to finally set up an accurate laboratory protocol to validate its dosage in CSF. RESULTS:MR-proADM is highly stable in CSF samples stored at room temperature for up to 48 h, allowing it to be measured with confidence also in CSF samples that may be left on the bench for several hours. In addition, the repeatability and within-laboratory precision of the MR-proADM assay using CSF samples appeared equal to or better than those obtained by the manufacturer using plasma samples, allowing the use of this assay, with high precision, also for CSF samples. CONCLUSION:The reliable measure of MR-proADM in CSF and the role of this molecule in CNS will allow its introduction in the diagnostic process of infectious, inflammatory, and degenerative neurological diseases.

Hymenoptera anaphylaxis led to the death of a bee and wasp venom sensitized 41-year-old man suffering from systemic indolent mastocytosis. While at work in a vineyard, the man suffered a serious anaphylactic crisis and cardiovascular arrest; despite ongoing attempts of resuscitation, he died in hospital 12 h after being stung. Autopsy confirmed that death was due to post-anoxic brain damage, cardiovascular shock, disseminated intravascular coagulation (DIC) and multi-organ failure (MOF). ICU blood samples drawn before the patient’s death from the distal extremity of the pulmonary catheter revealed central blood tryptase levels of 8955 ng/mL; samples drawn 6 days after death, at autopsy, confirmed anaphylaxis diagnostic central blood total tryptase levels (4977 ng/mL) and peripheral blood levels (319 ng/mL); IgE levels in ICU blood sample suggested that the farmer was a responder to venom immunoteraphy (VIT) for Apis Mellifera (IgE 0.44 kUI/L) but not for Polistes Dominulus (IgE 3.13 kUI/L) yet. The comparison of perimortem laboratory results was crucial, in association with autopsy findings and circumstantial data, in ascertaining that death was caused by a wasp venom anaphylactic reaction, with key findings being: 1) Significantly high pre-mortem (8955 ng/mL) and post-mortem (4977 ng/mL) central blood tryptase levels. 2) High post-mortem peripheral blood tryptase levels (319 ng/mL). 3) High pre-mortem central blood IgE antibodies against Polistes Dominulus.

BACKGROUND: Gibberellin-regulated proteins (GRP) are small glycoproteins (63 AA) of low molecular weight (7 kDa), stimulated by a phytohormone called gibberellin. They have been recently identified as a family of allergens, causing allergies to different types of fruits. There is evidence that primary sensitization occurs via the airways, induced by pollens of Cupressaceae. The aim of this study was to evaluate, in an Italian population of subjects sensitized to the GRP of peach (Pru p 7), simultaneous co-sensitizations to cypress pollens and to other molecules associated with fruit allergy, such as nsLTP (Pru p 3), PR-10 (Bet v1) and Profilin (Bet v2), in order to evaluate their potential role in modifying the severity of symptoms in the GRP sensitized patients.METHODS: A total of 60 subjects sensitized to Pru p 7 were consecutively enrolled in four Italian centers (Udine, Pordenone, Florence and Palermo): 28 men and 32 women with a mean age of 37.9 years (range 11-79). Specific IgE (sIgE) to Pru p 7, Pru p 3, Bet v 1, Bet v 2, cypress pollen extract (Cup s) and to its major allergen (Cup a 1) were tested in all studied patients with the ImmunoCAP system (Thermo Fisher Scientific, Uppsala, Sweden), and the cutoff was selected at 0.1 kUA/L.RESULTS: Mean value (± SD) of sIgE for Pru p 7 in the whole studied population was 4.3±5.43 kUA/L, with no significant differences between the Northern (3.16±6.21 kUA/L) and Southern Italian population (5.42±6.7 kUA/L) (non-significant P value). The percentages of sensitization to Cup s, Cup a 1, Pru p 3, Bet v 1 and Bet v 2 in the whole studied population were 90%, 83.3%, 45.8%, 40% and 30%, respectively; in subjects living in Northern Italy, the percentages of sensitization were 96.4%, 80%, 50%, 73.3% and 40%, while in subjects living in Southern Italy 83.3%, 86.7%, 40%, 6.7% and 20%, respectively. The only significant difference between North and South was for PR-10 (P<0.0001). Simultaneous sensitization to Pru p 7 and PR-10 is associated with a lower risk of anaphylaxis (OR=0.125), whereas subjects with co-sensitization to Pru p 3 had the highest risk of anaphylaxis in our case series (OR=2.916), but without reaching statistical significance. The fruit most frequently associated with allergic reactions was peach (26/40), followed by orange (12/40), kiwi, lemon, tomato (5/40), strawberry (3/40) and, to a lesser extent, other foods.CONCLUSIONS: The study confirmed a very high association between sensitization to Pru p 7 and cypress pollen. A high percentage of co-sensitization to nsLTP, PR-10 and profilin has been shown, but only the frequency of PR-10 sensitization differed between North and South Italy. Co-sensitization to PR-10 resulted as a protective factor for anaphylaxis. Peach and citrus have been the fruits most associated with GRP allergy in Italy.

COVID-19 is heterogeneous; therefore, it is crucial to identify early biomarkers for adverse outcomes. Extracellular vesicles (EV) are involved in the pathophysiology of COVID-19 and have both negative and positive effects. The objective of this study was to identify the potential role of EV in the prognostic stratification of COVID-19 patients. A total of 146 patients with severe or critical COVID-19 were enrolled. Demographic and comorbidity characteristics were collected, together with routine haematology, blood chemistry and lymphocyte subpopulation data. Flow cytometric characterization of the dimensional and antigenic properties of COVID-19 patients' plasma EVs was conducted. Elastic net logistic regression with cross-validation was employed to identify the best model for classifying critically ill patients. Features of smaller EVs (i.e. the fraction of EVs smaller than 200 nm expressing either cluster of differentiation [CD] 31, CD 140b or CD 42b), albuminemia and the percentage of monocytes expressing human leukocyte antigen DR (HLA-DR) were associated with a better outcome. Conversely, the proportion of larger EVs expressing N-cadherin, CD 34, CD 56, CD31 or CD 45, interleukin 6, red cell width distribution (RDW), N-terminal pro-brain natriuretic peptide (NT-proBNP), age, procalcitonin, Charlson Comorbidity Index and pro-adrenomedullin were associated with disease severity. Therefore, the simultaneous assessment of EV dimensions and their antigenic properties complements laboratory workup and helps in patient stratification.

BACKGROUND: The diagnosis of Hymenoptera venom allergy (HVA) relies on detailed anamnesis, skin tests and determination of specific IgE (sIgE) with extractive and molecular allergens of Apidae and Vespidae. In many patients, however, multiple venoms sIgE positivity is detected and it is not always possible to clearly determine the primary sensitization or whether there is true double sensitization, and therefore to prescribe a proper venom-specific immunotherapy (VIT). In these cases, the in vitro sIgE inhibition test can add valuable information. However, this test requires extensive experience and has some limitations in case of low sIgE values and in case of high levels of sIgE anti-cross reactive carbohydrate determinants (CCD). Recently, the use of basophil activation test (BAT) has been recommended in order to identify the primary sensitization in subjects in which molecular testing and/or sIgE inhibition have been inconclusive. Aim of the study was to evaluate the usefulness of BAT in a selected cohort of subjects who experienced allergic reactions following hymenoptera sting, history suggestive of Vespid sting and inconclusive sIgE assay.METHODS: Nineteen subjects with allergic reactions following hymenoptera sting (17 with systemic reactions and two with extensive local reactions) were studied. Of those, six patients showed multiple sIgE positivity for Vespidae and positivity sIgE for Apis mellifera (Apis m) and anti-CCD (5/6) too; six patients complained reactions after hymenoptera sting but with negativity of Apis m and Vespidae sIgE (≤0.10 kU/L), and seven patients showed very low sIgE levels (0.11-0.84 kU/L) for extractive and/or molecular Vespidae allergens. In all subjects, the following were performed: the sIgE assay for Vespula sp, Polistes dominulus (Polistes d), Vespa crabro, Apis m, Ves v 1, Ves v 5 and Pol d 5 (ImmunoCAP 1000, Thermofisher Scientific), and BAT in which extractive venoms of Vespula sp (BAG2-I3) and Polistes d (BAG2-I77), (Bühlmann Laboratories AG), were used for basophil stimulation. The response, measured as percentage of activated basophils (CD63+) at the different venom concentrations, was evaluated by cytofluorimetric method with FACSCanto™ II (Becton Dickinson). The sIgE inhibition assay was performed by overnight incubation at 4 °C of serum with venom extract in solution (Anallergo), at decreasing concentrations of 300, 30, 3 and 0.3 µg/mL, followed by sIgE assay.RESULTS: BAT detected the primary sensitizer in 6/19 (32%) subjects including one with negative sIgE and three with very low sIgE, while sIgE assay identified the primary sensitizer in 5/19 (26%) including four concordant with BAT. BAT in 6/19 (32%) cases allowed diagnosis of dual sensitization, of which half (3/6) confirmed by inhibition test, five concordant with sIgE assay by molecular technique, and one with negative sIgE. In one of seven cases of dual sensitization evidenced by molecular testing, BAT was decisive and in one case negative. In 2/7 (29%) patients with negative sIgE for molecular allergens, BAT was positive for Vespula sp (in one of these, similar activation was obtained for Vespula sp and Polistes d at different venom concentrations).CONCLUSIONS: This study proved that BAT is useful in confirming true double sensitizations and slightly more sensitive than molecular testing in identifying single sensitization to Vespidae venom, both in cases with negative sIgE (≤ 0.10 kU/l), and in subjects with multiple positivities for Vespidae, even where anti-CCD antibodies are present. These data, therefore, confirm the importance of combining multiple laboratory methods for precision diagnosis of HVA and more accurate choice of VIT.

Background Mid-Regional pro-Adrenomedullin (MR-proADM) is an inflammatory biomarker that improves the prognostic assessment of patients with sepsis, septic shock and organ failure. Previous studies of MR-proADM have primarily focussed on bacterial infections. A limited number of small and monocentric studies have examined MR-proADM as a prognostic factor in patients infected with SARS-CoV-2, however there is need for multicenter validation. An evaluation of its utility in predicting need for hospitalisation in viral infections was also performed. Methods An observational retrospective analysis of 1861 patients, with SARS-CoV-2 confirmed by RT-qPCR, from 10 hospitals across Europe was performed. Biomarkers, taken upon presentation to Emergency Departments (ED), clinical scores, patient demographics and outcomes were collected. Multiclass random forest classifier models were generated as well as calculation of area under the curve analysis. The primary endpoint was hospital admission with and without death. Results Patients suitable for safe discharge from Emergency Departments could be identified through an MR-proADM value of ≤ 1.02 nmol/L in combination with a CRP (C-Reactive Protein) of ≤ 20.2 mg/L and age ≤ 64, or in combination with a SOFA (Sequential Organ Failure Assessment) score < 2 if MR-proADM was ≤ 0.83 nmol/L regardless of age. Those at an increased risk of mortality could be identified upon presentation to secondary care with an MR-proADM value of > 0.85 nmol/L, in combination with a SOFA score ≥ 2 and LDH > 720 U/L, or in combination with a CRP > 29.26 mg/L and age ≤ 64, when MR-proADM was > 1.02 nmol/L. Conclusions This international study suggests that for patients presenting to the ED with confirmed SARS-CoV-2 infection, MR-proADM in combination with age and CRP or with the patient’s SOFA score could identify patients at low risk where outpatient treatment may be safe.

BACKGROUND: In the last ten years, the introduction of the component resolved diagnosis (CRD) has revolutionized allergy diagnostics with a strong clinical impact in respiratory, hymenoptera and food allergy. However, its use and the diagnostic algorithms implemented by each laboratory seem somewhat different across the national territory. In order to have a clearer picture on how this diagnostics is used in Italy, the Study Group in Allergology (GDS-ALL) of the Italian Society of Clinical Pathology and Laboratory Medicine (SIPMeL) has conducted a survey relating to the year 2019, among Italian laboratories that deal with allergy diagnostics to assess the level of implementation of new technologies, the knowledge and application of the recommended diagnostic algorithms and, more generally, the degree and type of organization adopted.METHODS: A questionnaire consisting of 47 items divided into five sections was distributed in January 2020 through the SurveyMonkey (Momentive Inc., San Mateo, CA, USA) platform to public and private laboratories throughout the country. The questions were formulated to investigate aspects relating to the type of laboratory, the number of users served, and the number of allergy tests carried out, the type of requests received and their management, the technologies used and their level of automation, the reference intervals and, finally, the relationship with patients, hospital clinicians and general practitioners.RESULTS: Seventy-four laboratories representing all Italian regions responded to the survey, of which 68% are located in public hospitals, 12% are related to university hospitals and 20% to private structures. 9.9% of the participants stated that they had performed specific IgE on several patients greater than 50,000/year, 15.5% between 10-50,000, another 15.5% between 5-10,000, 31% between 1-5000 and the remaining 28.1%, mainly represented by private structures, with less than 1000 patients per year. Among the methods of investigation, 83% of the participants use the fluoroimmunoenzymatic technique (FEIA) and 21% chemiluminescence assays (CLIA) (4% use both technologies). 85% of the laboratories interviewed perform molecular diagnostics and 29% of them are also equipped with the multiplex platform. Almost all laboratories make use of complete automation: 52% of the participants stated that they include an interpretative comment in the report. More than half of the laboratories claim to have of collaborative relationship with hospital clinicians, and 45% declare that they have a satisfactory relationship with general practitioners. The consultancy activity regarding allergy diagnostics is practiced by more than half of the participants.CONCLUSIONS: The results obtained from the survey represent a snapshot of the current situation of Italian allergology laboratories, highlighting how most of them have responded positively to the needs for change related to the increasing request of molecular diagnostics in medical prescriptions. However, improvement in the correct use of the proposed algorithms is still necessary in order to obtain an accurate profile of allergenic sensitization effective in supporting the clinical decision.

Mid Regional pro-ADM (MR-proADM) is a promising novel biomarker in the evaluation of deteriorating patients and an emergent prognosis factor in patients with sepsis, septic shock and organ failure. It can be induced by bacteria, fungi or viruses. We hypothesized that the assessment of MR-proADM, with or without other inflammatory cytokines, as part of a clinical assessment of COVID-19 patients at hospital admission, may assist in identifying those likely to develop severe disease. A pragmatic retrospective analysis was performed on a complete data set from 111 patients admitted to Udine University Hospital, in northern Italy, from 25th March to 15th May 2020, affected by SARS-CoV-2 pneumonia. Clinical scoring systems (SOFA score, WHO disease severity class, SIMEU clinical phenotype), cytokines (IL-6, IL-1b, IL-8, TNF-α), and MR-proADM were measured. Demographic, clinical and outcome data were collected for analysis. At multivariate analysis, high MR-proADM levels were significantly associated with negative outcome (death or orotracheal intubation, IOT), with an odds ratio of 4.284 [1.893–11.413], together with increased neutrophil count (OR = 1.029 [1.011–1.049]) and WHO disease severity class (OR = 7.632 [5.871–19.496]). AUROC analysis showed a good discriminative performance of MR-proADM (AUROC: 0.849 [95% Cl 0.771–0.730]; p < 0.0001). The optimal value of MR-proADM to discriminate combined event of death or IOT is 0.895 nmol/l, with a sensitivity of 0.857 [95% Cl 0.728–0.987] and a specificity of 0.687 [95% Cl 0.587–0.787]. This study shows an association between MR-proADM levels and the severity of COVID-19. The assessment of MR-proADM combined with clinical scoring systems could be of great value in triaging, evaluating possible escalation of therapies, and admission avoidance or inclusion into trials. Larger prospective and controlled studies are needed to confirm these findings.

Tryptase is a serine protease produced by mast cells and released into the circulation after IgE-mediated or non-IgE-mediated stimuli. Its dosage is therefore of great utility in the diagnosis of anaphylaxis and of mastocytosis. In this review, we describe the various aspects related to the molecular characteristics of tryptase and its biological effects, the genetic basis of its production and the release kinetics. Recommendations are also given on the best procedure for a correct definition of the reference values in relation to the inter-individual variability and to the correct determination of tryptase in blood and other biological liquids, in the diagnosis of anaphylaxis (from drugs, food or insect bites), death from anaphylaxis (post-mortem assessment) and cutaneous or systemic mastocytosis and mast cell activation syndrome.

Tryptase is a serine protease produced by mast cells and released into the circulation after IgE-mediated or non-IgE-mediated stimuli. Its dosage is therefore of great utility in the diagnosis of anaphylaxis and of mastocytosis. In this review, we describe the various aspects related to the molecular characteristics of tryptase and its biological effects, the genetic basis of its production and the release kinetics. Recommendations are also given on the best procedure for a correct definition of the reference values in relation to the inter-individual variability and to the correct determination of tryptase in blood and other biological liquids, in the diagnosis of anaphylaxis (from drugs, food or insect bites), death from anaphylaxis (post-mortem assessment) and cutaneous or systemic mastocytosis and mast cell activation syndrome.

L’allergia al kiwi è attualmente una delle più comuni cause di allergia alimentare e offre un chiaro esempio degli effetti dell’introduzione di un nuovo alimento nella catena alimentare. In recenti studi epidemiologici europei risulta essere tra le prime dieci fonti di allergia. Spesso si associa a sensibilizzazione a polline di betulla e si manifesta con sintomatologia localizzata al cavo orale (sindrome orale allergica, SOA). Alcuni pazienti presentano, invece, sintomi sistemici come orticaria acuta, angioedema, manifestazioni gastroenteriche, sintomi cardiovascolari o anafilassi. Sono stati a oggi identificati 13 allergeni molecolari di kiwi, di cui 4 disponibili per la ricerca di IgE specifiche nel pannello del test microarray: 3 sono componenti specifiche di origine nativa (Act d 1, Act d 2, Act d 5) e 1 è una proteina ricombinante cross-reattiva appartenente alla famiglia delle PR-10 (Act d 8). Scopo dello studio è stato identificare il profilo di sensibilizzazione allergenica in un gruppo di pazienti pediatrici con sospetto di allergia al kiwi, che presentavano sintomi, nella maggioranza dei casi, di tipo sistemico.

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.

I test di laboratorio sono fondamentali per identificare il veleno di Imenottero causa di allergia sistemica, e quindi per la scelta dell’immunoterapia specifica. La presenza di positività multiple ai test cutanei e sierici suggerisce l’esecuzione di esami di approfondimento per conoscere se si tratti di cross-reattività tra proteine con elevata omologia, in particolare di diversi generi di Vespidi, o di vere sensibilizzazioni indotte da punture di più specie di Imenotteri. Le linee guida italiane ed europee indicano di eseguire, nei casi complessi, il test di inibizione IgE specifiche. Scopo del nostro studio è stato valutare la sensibilità degli allergeni molecolari ricombinanti, Ves v 5 e Pol d 5, confrontando i risultati IgE con la diagnosi del test di inibizione.

Il Gruppo di Studio in Autoimmunologia della SIPMeL ha riveduto e aggiornato le linee guida già proposte nel 2005 alla luce delle evidenze scientifiche comparse negli ultimi 10 anni per l'inquadramento diagnostico e il monitoraggio del paziente celiaco. L'identificazione della non celiac gluten sensitivity come entità nosologica a se stante ha reso inoltre necessari alcuni chiarimenti su aspetti diagnostici e classificativi. L'attuale versione ripropone sotto forma di raccomandazioni le indicazioni per un appropriato utilizzo dei test sierologici oggi disponibili, dei test genetici in grado di definire l'appartenenza ai gruppi a rischio e dei diversi quadri istologici, definendo gli step diagnostici e interpretativi in maniera diversificata a seconda della motivazione della richiesta (diagnosi, monitoraggio, gruppi a rischio) e dell'età dei pazienti. Le raccomandazioni sono il risultato delle più recenti evidenze disponibili in letteratura, del consenso tra i componenti del gruppo di studio e del lavoro interdisciplinare tra patologi clinici, immunologi e anatomo-patologi e ha l'obiettivo di supportare il lavoro del medico nell'approccio quotidiano alla diagnosi delle patologie glutine-associate.

We report a case of an eleven years old girl who was referred to our Allergy Outpatient Clinic for the revaluation of a hazelnut allergy. During her infancy she was successfully desensitised to milk and egg. Afterward she had been followed by another Allergy Unit where, according to skin prick test and specific IgE dosage, it had been suggested to strictly avoid peanut and all treenuts, although clinical history was not suggestive of treenuts allergy. She was also provided with an auto-injectable adrenaline, due to the high risk of severe reactions to treenuts. No oral provocation test was performed to validate diagnosis and adrenaline prescription.

Objective To determine the genetic profile of celiac disease (CD) in Libyan children with type 1 diabetes as there are no data on the frequency of human leukocyte antigen (HLA)-related CD-predisposing genes in diabetic patients in Libya. Methods We randomly studied 218 Libyan type 1 diabetic children. The mean age was 12.2±4.6 years; 56% were female patients. The mean duration of diabetes was 4.7±4.0 years. All patients were screened for CD with IgA tissue-transglutaminase (tTG) and endomysium antibodies. Patients with positive immunological screen were programmed for a small-bowel biopsy. HLA-DRB1* and HLA-DQB1* were genotyped in all tTG-positive patients. Results Twenty-seven (12.4%) out of 218 patients with type1 diabetes had positive tTG, and 20 (9.2%) of these patients were positive for endomysium antibodies. Five patients (5/27) were already known cases of biopsy-proven CD. Biopsy was not performed in two patients. One biopsy result was normal, whereas 19 biopsies demonstrated morphological changes consistent with CD. Forty-eight percent of the anti-tTG-positive group were homozygous for HLA-DQ2, whereas 75% of biopsy-proven CD patients had HLA-DQ2, 21% had HLA-DQ2/DQ8, and 4% had HLA-DQ8. In addition, the majority (70%) carried HLA-DQ2 linkage with HLA-DRB1*03. Conclusion Overall, biopsy-confirmed prevalence of CD was 11% (24 of 218). The present study confirms that CD in the Libyan type 1 diabetic population is high when compared with European and US studies, and for the first time we document that this population shares similar HLA-DQ2 genotype. This supports the theory regarding the role of the environment as an important factor in CD development in this part of the world.