Biomedical subjects

Alberto Falorni

Publications and source records attributed to Alberto Falorni.

22 records · Page 2Linked to original sources

PubMed2002

Autoantibodies in autoimmune polyendocrine syndrome type II.

The autoimmune polyendocrine syndrome type II (APS-II) is characterized by the association of autoimmune Addison's disease with thyroid autoimmune diseases or type-1 diabetes mellitus. 21-Hydroxylase autoantibodies enable the accurate diagnosis of autoimmune Addison's disease and, in patients with other endocrine autoimmune diseases, identify subjects at high risk for clinical adrenal insufficiency. 17 alpha-Hydroxylase (17OH) and side-chain-cleavage enzyme (P450scc) are target autoantigens of steroid-cell autoantibodies, and in women with Addison's disease, 17OH autoantibodies and P450scc autoantibodies are markers of increased risk for premature ovarian failure. Thyroperoxidase autoantibodies, thyroglobulin autoantibodies, H+/K(+)-ATPase autoantibodies, and GAD65 autoantibodies are frequently detected in patients with isolated Addison's or APS-II. Screening for other organ-specific autoimmune diseases should be performed in every patient with at least one major disease component of APS-II.

Addison Disease↗

PubMed2002

Dehydroepiandrosterone, 17alpha-hydroxyprogesterone and aldosterone responses to the low-dose (1 micro g) ACTH test in subjects with preclinical adrenal autoimmunity.

OBJECTIVE: The appearance of 21-hydroxylase autoantibodies (21OHAbs) identifies subjects with preclinical adrenal insufficiency. In 21OHAb-positive subjects, the adrenocortical function is best evaluated by peak cortisol (F) levels after the low-dose (1 micro g) ACTH stimulation test (LDT). No information is currently available on the correlation between F and other adrenocortical hormone responses to the LDT in subjects with an ongoing autoimmune adrenal process. In this study, we tested the hypothesis that the dehydroepiandrosterone (DHEA), 17alpha-hydroxyprogesterone (17OHP) and aldosterone (A) responses to the LDT are consensual to that of F during the preclinical phase of autoimmune adrenal insufficiency. DESIGN AND PATIENTS: We studied 12 subjects positive for 21OHAb, in the absence of clinical signs of adrenal insufficiency. On the basis of peak F levels after the LDT, and according to the lower level of normal observed in 15 healthy volunteers (510.4 nmol/l), patients were subdivided into two groups: group A, n = 6 subjects with normal F response; and group B, n = 6 subjects with impaired F response. Results were expressed as absolute delta increase (Delta) between peak and basal levels. RESULTS: DeltaF was significantly higher in group A (314.5 +/- 115.8 nmol/l) than in group B (151.7 +/- 88.2 nmol/l) (P = 0.041). DeltaDHEA and Delta17OHP were also significantly higher in group A (17.0 +/- 13.5 nmol/l and 6.1 +/- 4.4 nmol/l, respectively) than in group B (0.69 +/- 2.25 nmol/l and 1.9 +/- 1.7 nmol/l, respectively) (P = 0.002 and P = 0.041). The difference in DeltaA between the two groups did not reach statistical significance (group A 321.8 +/- 272.0 pmol/l vs. group B 157.0 +/- 154.0 pmol/l). DeltaDHEA, Delta17OHP and DeltaA tended to correlate positively with DeltaF (P = 0.039, P = 0.039 and P = 0.044, respectively), but the correlations did not reach significance after correction of the P-value. CONCLUSIONS: Our study demonstrates a high concordance between F and DHEA, 17OHP and A responses to the LDT in subjects with preclinical adrenal autoimmunity, thus strengthening the concept that the LDT is an accurate test to identify early adrenal dysfunction.

17-alpha-Hydroxyprogesterone↗

PubMed2002

Autoantibody profile and epitope mapping in latent autoimmune diabetes in adults.

The presence of islet cell autoantibodies in adult diabetic subjects who do not require insulin treatment for at least six months after the initial clinical diagnosis identifies the so-called latent autoimmune diabetes in the adult (LADA). Glutamic acid decarboxylase autoantibodies (GAD65Ab) are the best immune marker to identify LADA patients, while other islet autoantibodies, such as IA-2 autoantibodies, have a very low diagnostic sensitivity. Islet cell antibodies, as detected by indirect immunofluorescence, may improve the diagnostic specificity of the immune analysis when detected in GAD65Ab-positive patients. Although the majority of LADA patients progresses towards insulin dependency within a few years after the diagnosis, this form of diabetes is heterogeneous. The presence of high titers of GAD65Ab and/or GAD65Ab directed towards COOH-terminal epitopes of the autoantigen (GAD65-CAb) identifies a subgroup of LADA patients with clinical characteristics similar to those of typical type 1 diabetes and at very high risk of progression toward insulin dependency. On the other hand, low titers of GAD65Ab, or the exclusive presence of GAD65Ab directed to middle epitopes of the autoantigen, characterizes LADA patients with clinical characteristics almost indistinguishable from those of GAD65Ab-negative type 2 diabetic patients. LADA subjects, especially in the presence of high titers of GAD65Ab and/or GAD65-CAb, have an increased risk for other organ-specific autoimmune diseases such as thyroid autoimmune diseases or autoimmune Addison's. LADA should be considered a major component of the autoimmune polyendocrine syndromes, and screening for other autoimmune diseases should be performed in all LADA patients.

Age of Onset↗

PubMed2002

CTLA-4 gene polymorphism contributes to the genetic risk for latent autoimmune diabetes in adults.

Latent autoimmune diabetes in adults (LADA) is identified by the presence of GAD65 autoantibodies in diabetic patients who do not require insulin treatment for at least six months after the diagnosis. Previous studies have shown that the risk for LADA, similarly to type 1 diabetes mellitus (T1DM), is increased in subjects carrying the HLA-DRB1*03-DQA1*0501-DQB1*0201 and/or HLA-DRB1*04-DQA1*0301-DQB1*0302 haplotypes. In the present study, we investigated the association between LADA and the CTLA-4 A/G polymorphism, another gene polymorphism associated with T1DM and other autoimmune diseases. The heterozygous A/G genotype was significantly more frequent among 80 LADA (69%) than among 85 healthy subjects of similar age and geographical provenience (47%) (OR = 2.47, corrected P = 0.023). Conversely, the homozygous A/A genotype was significantly less frequent in LADA subjects than in healthy controls (26% vs. 47%, OR = 0.4, corrected P = 0.028). The results of our study show that LADA is positively associated with the CTLA-4 A/G genotype, similarly to T1DM, thus providing further supporting evidence of the autoimmune origin of this form of diabetes mellitus of the adult.

Abatacept↗