Presence of diabetes-specific autoimmunity in women with gestational diabetes mellitus (GDM) predicts impaired glucose regulation at follow-up.

PURPOSE: Gestational diabetes mellitus (GDM) is the most frequent complication of pregnancy; around 10% of GDM cases may be determined by autoimmunity, and our aims were to establish the role of autoimmunity in a population of Sardinian women affected by GDM, to find predictive factors for autoimmune GDM, and to determine type 1 diabetes (T1D) auto-antibodies (Aabs) together with glucose tolerance after a mean 21.2 months of follow-up. METHODS: We consecutively recruited 143 women affected by GDM and 60 without GDM; clinical data and pregnancy outcomes were obtained by outpatient visit or phone recall. T1D auto-antibodies GADA, IA2-A, IAA, ZnT8-A were measured in the whole population at baseline, and in the Aab-positive women at follow-up. RESULTS: The overall prevalence of autoimmunity was 6.4% (13/203). No significant difference was found in the prevalence of auto-antibodies between GDM (5.6%) and control (8.3%) women, neither in antibody titres. Highest titres for GADA and ZnT8-A were observed in the control group; no phenotypic factors were predictive for autoimmune GDM. Diabetes-related autoantibodies were still present in all the GDM women at follow-up, and their presence was associated with a 2.65 (p < 0.0016) relative risk (RR) of glucose impairment. CONCLUSION: We observed a low prevalence (5.6%) of diabetes-related autoimmunity in our GDM cohort, consistent with the prevalence reported in previous studies. It was not possible to uncover features predictive of autoimmune GDM. However, given the significant risk of a persistent impaired glycemic regulation at follow-up, it is advisable to control for glucose tolerance in GDM women with diabetes-related autoimmunity.

High prevalence of diabetes-specific autoimmunity in first-degree relatives of Sardinian patients with type 1 diabetes.

BACKGROUND: The incidence of type 1 diabetes mellitus (T1DM) in Sardinia is among the highest in the world (44.8 cases/100,000 person-years). Recommendations of the Immunology of Diabetes Society advise evaluating autoantibody positivity in first-degree relatives (FDRs) of patients with T1DM, for their higher risk to develop the disease. The aim of this study was to determine the prevalence of beta-cell autoimmunity in FDRs of T1DM patients in Sardinia. METHODS: A total of 188 Sardinian families were recruited in collaboration between diabetes and pediatric units of university and district hospitals in Sardinia. The recruitment involved 188 patients with diagnosed T1DM and all their available FDRs (n = 447). Autoantibodies (Aabs) against GAD, IA2, insulin, and ZnT8 were measured in all subjects. Human leukocyte antigen (HLA) risk genotypes (HLA-DR and DQ loci) were analyzed in 43 Aabs-positive FDR. RESULTS: The prevalence of Aabs (any type of autoantibody, single or multiple) in FDR was 11.9% (53/447). Of those with autoantibodies, 62.3% (33/53) were positive to only 1 autoantibody, 22.6% (12/53) had 2 autoantibodies, 7.55% (4/53) had 3 autoantibodies, and 7.55% (4/53) had all 4 autoantibodies. Typing of HLA-DR and DQ loci showed that 89% of FDR carried moderate- to high-risk genotypes, with only 5 FDR with low-risk genotypes. CONCLUSIONS: The prevalence of T1DM autoantibodies in FDRs of T1DM patients was very high (11.9%) in the Sardinian population, higher than in other populations from the United States and Europe, and similar to that observed in Finland. Autoantibody positivity strongly associated with HLA risk. This study provides evidence of the high risk of T1DM in FDR of T1DM patients in Sardinia and warrants longitudinal follow-up to estimate the risk of progression to T1DM in high-risk populations.

The outcome of acute hepatitis C predicted by the evolution of the viral quasispecies.

The mechanisms by which hepatitis C virus (HCV) induces chronic infection in the vast majority of infected individuals are unknown. Sequences within the HCV E1 and E2 envelope genes were analyzed during the acute phase of hepatitis C in 12 patients with different clinical outcomes. Acute resolving hepatitis was associated with relative evolutionary stasis of the heterogeneous viral population (quasispecies), whereas progressing hepatitis correlated with genetic evolution of HCV. Consistent with the hypothesis of selective pressure by the host immune system, the sequence changes occurred almost exclusively within the hypervariable region 1 of the E2 gene and were temporally correlated with antibody seroconversion. These data indicate that the evolutionary dynamics of the HCV quasispecies during the acute phase of hepatitis C predict whether the infection will resolve or become chronic.

Prevention of hepatitis C virus infection in chimpanzees by hyperimmune serum against the hypervariable region 1 of the envelope 2 protein.

The identification of the neutralization domains of hepatitis C virus (HCV) is essential for the development of an effective vaccine. Here, we show that the hypervariable region 1 (HVR1) of the envelope 2 (E2) protein is a critical neutralization domain of HCV. Neutralization of HCV in vitro was attempted with a rabbit hyperimmune serum raised against a homologous synthetic peptide derived from the HVR1 of the E2 protein, and the residual infectivity was evaluated by inoculation of HCV-seronegative chimpanzees. The source of HCV was plasma obtained from a patient (H) during the acute phase of posttransfusion non-A, non-B hepatitis, which had been titered for infectivity in chimpanzees. The anti-HVR1 antiserum induced protection against homologous HCV infection in chimpanzees, but not against the emergence of neutralization escape mutants that were found to be already present in the complex viral quasispecies of the inoculum. The finding that HVR1 can elicit protective immunity opens new perspectives for the development of effective preventive strategies. However, the identification of the most variable region of HCV as a critical neutralization domain poses a major challenge for the development of a broadly reactive vaccine against HCV.

Epidemiology of infection with HIV-1 in Sardinia: a multicentre prospective study.

To study the spread of human immunodeficiency virus type 1 (HIV-1) in Sardinia, we conducted a multicentre prospective study of the prevalence of antibody to HIV-1 (anti-HIV-1) in various populations during 1985-1989. The highest anti-HIV-1 prevalence (61.4%) was found in intravenous drug users. Anti-HIV-1 was found in 32% of haemophiliacs, 4.2% of thalassemics and less than 1% in the other groups. We conclude that control of HIV infection in Sardinia will require a major expansion of prevention and treatment programs for drug addiction.

T lymphocyte subsets and viral infections in Sardinian parenteral drug abusers: relationship to HIV infection.

To investigate whether the human immunodeficiency virus (HIV) infection or the abuse of narcotic drugs or other viral infections may be responsible for immunologic abnormalities in parenteral drug abusers, sera from 168 consecutive individual patients were collected from 1985 to 1986. The sera were tested for antibody to HIV (anti-HIV), and the clinical, immunologic, and serologic characteristics of 83 seropositive and 53 seronegative parenteral drug abusers were compared. The presence of anti-HIV was significantly associated with a decreased number of T helper lymphocytes (P less than .001), a reduced T helper/suppressor ratio (P less than .001). Of the 83 seropositive patients, 63 (76%) had generalized lymphadenopathy and 16 (18%) had AIDS-related complex. No patient had AIDS. Parenteral drug abusers with AIDS-related complex had significant reductions in the number of T helper cells (P less than .01) and the T helper/suppressor ratio (P less than .01) compared with patients with lymphadenopathy syndrome (LAS), suggesting that parenteral drug abusers with HIV infection develop a progressive immunodeficiency. IgG antibody to cytomegalovirus was found in 75% of anti-HIV-positive and 45% of anti-HIV-negative parenteral drug abusers (P less than .01), but significant associations between anti-HIV and markers for other viruses were not found. Our data confirm that HIV infection is the major cause of low T helper cells and reversed T helper/suppressor ratio in parenteral drug abusers.(ABSTRACT TRUNCATED AT 250 WORDS)