Use of DPB1 T-cell epitope algorithm among italian transplant centers: A survey on behalf of Associazione Italiana di Immunogenetica e Biologia dei Trapianti.

The HLA-DPB1 locus has been demonstrated to have a significant role on patients' outcome after allogeneic HSCT, and the so-called T-cell epitope (TCE) algorithm has been incorporated in international guidelines for the selection of unrelated donors. The purpose of the present study is to measure, through a national survey conducted on behalf of the Associazione Italiana di Immunogenetica e Biologia dei Trapianti (AIBT), the extent of awareness and use of HLA-DPB1 TCE-based algorithms during the donor search. 89% of the HLA laboratories answered to a short questionnaire and the results showed a progressive increase of the laboratories typing DPB1 in patients and their potential donors during the search (from 44% to 79% during the 2010-2019 period) as well as the application of a TCE-based algorithm for the donor choice whenever possible (from 24% to 65% during the same period). The DP-permissiveness status is detailed in the official HLA typing report by 12%, 32% and 50% of laboratories in 2010, 2015 and 2019, respectively. The present data indicate an encouraging raise in the awareness of the HLA-DPB1 role in unrelated donor selection; noteworthy, mentioning the TCE-based permissiveness status in the HLA typing report of each potential unrelated donor represents a notable mean to raise awareness among transplant physicians and to support them in their task of choosing the best donor. Nonetheless, despite the compelling evidence of the predictive ability of TCE-based algorithms, further efforts are still needed to extend its application to all transplant centers in Italy.

Addison's disease: a survey on 633 patients in Padova.

OBJECTIVE: Addison's disease (AD) is a rare endocrine condition. DESIGN: We aimed to evaluate clinical, immunologic, adrenal imaging, and genetic features in 633 Italian patients with AD followed up since 1967. METHODS: Adrenal cortex autoantibodies, presence of other autoimmune and nonautoimmune diseases, nonadrenal autoantibodies, adrenal imaging, and genetic profile for HLA-DRB1 and AIRE were analyzed. RESULTS: A total of 492 (77.7%) patients were found to be affected by autoimmune AD (A-AD), 57 (9%) tuberculous AD, 29 (4.6%) genetic-associated AD, 10 (1.6%) adrenal cancer, six (0.94%) post-surgical AD, four (0.6%) vascular disorder-related AD, three (0.5%) post-infectious AD, and 32 (5.1%) were defined as idiopathic. Adrenal cortex antibodies were detected in the vast majority (88100%) of patients with recent onset A-AD, but in none of those with nonautoimmune AD. Adrenal imaging revealed normal/atrophic glands in all A-AD patients: 88% of patients with A-AD had other clinical or subclinical autoimmune diseases or were positive for nonadrenal autoantibodies. Based on the coexistence of other autoimmune disorders, 65.6% of patients with A-AD were found to have type 2 autoimmune polyendocrine syndrome (APS2), 14.4% have APS1, and 8.5% have APS4. Class II HLA alleles DRB1*03 and DRB1*04 were increased, and DRB1*01, DRB1*07, DRB1*013 were reduced in APS2 patients when compared with controls. Of the patients with APS1, 96% were revealed to have AIRE gene mutations. CONCLUSIONS: A-AD is the most prevalent form of adrenal insufficiency in Italy, and ∼90% of the patients are adrenal autoantibody-positive at the onset. Assessment of patients with A-AD for the presence of other autoimmune diseases should be helpful in monitoring and diagnosing APS types 1, 2, or 4 and improving patients' care.

KIR/HLA-I mismatching and risk of relapse in paediatric patients undergoing non-haploidentical allogeneic haematopoietic stem cell transplantation.

In HSCT setting, KIR-driven alloreactivity might be better predicted if the donor KIR genotype is considered in addition to the recipient HLA genotype. The prediction of NK cell alloreactivity relies on the missing ligand in the recipient, a scenario that can be found in HLA-identical and non-identical allotransplants. The aim of this study was to investigate at genetic level the prognostic impact of recipient HLA-I lacking for donor KIR on allotransplanted patients outcome. We analysed donors KIR genotype and HLA genotype of 60 paediatric patients who received related (n=15) or unrelated (n=45) transplantation. When patients were grouped based on the KIR gene type involved in the KIR/HLA-I mismatch, we did not observe any relapse in the group of patients characterized by mismatches involving only inhibitory KIR. On the contrary, all relapses were observed in patients showing at least one activating gene involved in the mismatch (p<0.05). Although the biological mechanism accounting for this putative genetic rule is still to be clarified, we suggest that a careful survey of KIR/HLA-I mismatching should be taken into account in the selection of donor in related and unrelated HSCT.

Lack of expression of inhibitory KIR3DL1 receptor in patients with natural killer cell-type lymphoproliferative disease of granular lymphocytes.

BACKGROUND: Natural killer cell-type lymphoproliferative disease of granular lymphocytes is a disorder characterized by chronic proliferation of CD3(-)CD16(+) granular lymphocytes. By flow cytometry analysis, we previously demonstrated a dysregulation in killer immunoglobulin-like receptor (KIR) expression in natural killer cells from patients with this lymphoproliferative disease, the activating KIR receptors being mostly expressed. We also found that patients with natural killer cell-type lymphoproliferative disease of granular lymphocytes usually had KIR genotypes characterized by multiple activating KIR genes. DESIGN AND METHODS: We investigated the mRNA levels of the KIR3DL1 inhibitory and the related KIR3DS1 activating receptors in 15 patients with natural killer cell-type lymphoproliferative disease of granular lymphocytes and in ten controls. These genes are usually expressed when present in the genome of the Caucasian population. RESULTS: We demonstrated the complete lack of KIR3DL1 expression in most of the patients analyzed, with the receptor being expressed in 13% of patients compared to in 90% of controls (P<0.01). Interestingly, studies of the methylation patterns of KIR3DL1 promoter showed a significantly higher methylation status (0.76 ± 0.12 SD) in patients than in healthy subjects (0.49±0.10 SD, P<0.01). The levels of expression of DNA methyl transferases, which are the enzymes responsible for DNA methylation, did not differ between patients and controls. CONCLUSIONS: In this study we showed, for the first time, a consistent down-regulation of the inhibitory KIR3DL1 signal due to marked methylation of its promoter, thus suggesting that together with the increased expression of activating receptors, the lack of the inhibitory signal could also play a role in the pathogenesis of natural killer cell-type lymphoproliferative disease of granular lymphocytes.

Antibodies to muscle and ganglionic acetylcholine receptors (AchR) in celiac disease.

BACKGROUND: About 2.5% of patients with idiopathic peripheral neuropathy or idiopathic dysautonomia have underlying celiac disease (CD). Antibodies to ganglioside have been reported in CD patients with neuropathy. No data are so far available on the presence in CD of acetylcholine receptor (AChR) antibodies. Muscle AChR antibodies are found in patients with myasthenia gravis, and ganglionic AChR antibodies in patients with autoimmune autonomic neuropathy. OBJECTIVE: To determine the frequency of AChR antibodies in CD patients and assess possible correlations with neurological manifestations. METHODS: Seventy CD patients (16 M, 54 F, mean age 36 years) underwent neurological and electrophysiological evaluation. AChR antibodies were detected with radioimmunoprecipitation assay. Sera from 15 age-matched patients with systemic lupus erythematosus (SLE) and 10 with Sjogren syndrome were studied as controls. RESULTS: None of our CD patients complained of autonomic symptoms or fatigable weakness. Borderline titres (0.03-0.05 nmol/l) of ganglionic AChR antibodies were present in 4 patients, one affected with type I diabetes and one with subclinical neuropathy. Three of the 4 patients underwent cardiovascular autonomic function tests, which showed no abnormalities. Low levels of ganglionic AChR antibodies (0.05-0.10 nmol/l) were found in 2 SLE control patients, one of whom had a severe sicca complex. Muscle AChR antibodies (>1.0 nmol/l) were found in two CD patient and one control patient with SLE. Neither had symptoms or signs of myasthenia gravis. DISCUSSION AND CONCLUSIONS: CD is occasionally associated with neurologic disease, and with antibody reactivity to neuronal antigens. None of our CD patients had autonomic failure or significant levels of ganglionic AChR antibodies. Two CD patient and one control with SLE had muscle AChR antibodies without clinical evidence of myasthenia. The presence of antibodies in CD and in SLE patients may reflect a non-specific autoimmune response in these patients or may indicate subclinical autoimmune autonomic and neuromuscular involvement.

Celiac disease in North Italian patients with autoimmune thyroid diseases.

BACKGROUND: Patients with autoimmune thyroid diseases (AITDs) are prone to develop other autoimmune manifestations and to display autoimmune polyendocrine syndromes. An increased prevalence of celiac disease (CD) was demonstrated in adult European and Italian patients with AITDs; conversely, an increased prevalence of AITDs was demonstrated in patients with CD. An IgA deficiency is the most frequent immunodeficiency in humans and, in general, high frequency of this disorder was demonstrated in those with autoimmune diseases. AIM: To define the prevalence of both CD and IgA deficiency in North Italian patients with AITDs. METHODS: 276 Italian patients with AITD were enrolled (mean age 42.6 years range 12-89, 186 of whom had chronic thyroiditis and 90 had Graves' disease). The tissue transglutaminase autoantibodies of the IgA class (IgA-tTGAbs) were evaluated using an ELISA method in these patients. Furthermore, the serological levels of the IgA were determined. RESULTS: Five of the patients (1.8%) were affected by previously diagnosed CD and were on a gluten-free diet. Ten out of the remaining 271 patients (3.6%) were found to be positive for celiac-related autoantibodies. All of these patients agreed to undergo endoscopy and duodenal biopsies and silent CD was found in 5 of them but 5 had not histopathological signs of CD. CD (clinical, silent or latent) was present in 15/276 (5.4%) of the North Italian patients with AITD; this prevalence is significantly higher with respect to the general population (p < 0.00001). The genetic pattern of the 10 patients with both AITDs and CD was characterized by the presence of DQ2 in 8 patients and DQ8 in 2. An IgA deficiency was present in 2/276 of the patients (0.72%). CONCLUSIONS: CD is significantly increased in patients with thyroid autoimmune disorders for this reason it is important to screen for CD in patients with AITDs.