The distribution of peripheral blood CD16/56 cytotoxic T and natural killer (NK) cells in Graves' disease patients is analyzed in order to correlate them with disease activity and with prognosis. Eighteen patients with Graves' disease, twenty-four patients with Hashimoto's thyroiditis and thirtytwo sex-and age-matched healthy control subjects were studied. Peripheral blood CD16/56 (cytotoxic T and NK) cells were analyzed by cytofluorometry. A decreased proportion of CD16/56þ and CD16/ 56þCD3þ cells were detected in Graves' disease patients when compared with thyroiditis patients and healthy control groups. No correlation was detected with serum free thyroxine. On diagnosis, patients who would require a radical treatment for thyrotoxicosis control showed a significant decrease of cytotoxic CD56þ T (CD3þ) and NK (CD3¹) cells compared with those who would maintain the euthyroid state after methimazole. These results suggest that the cytotoxic compartment, both T and NK cells, of the immune system is altered in patients with Graves' disease, independently of the functional thyroid status. Changes in peripheral blood lymphocytes in Graves' disease patients could be useful as predictive markers of an unfavorable outcome.

Infection by specific HCV genotypes (type 3 in HIV-infected patients and by type 1 in HIV-non infected ones) implies a higher risk of HCV viremia, whereas multiple HCV types infection is negatively associated with this probability. HIV coinfection does not influence the probability of HCV viremia.

DNA amplification of lngA, the structural gene of longus type IV pilus produced by human enterotoxigenicEscherichia coli (ETEC) was achieved by the use of specific oligonucleotide primers designed from the nucleotide sequence oflngA. A 630-bp fragment representing the entirelngA gene was amplified in eight prototype strains previously characterized as longus positive. Five ETEC strains producing colonization factor antigen III (CFA III) (also a type IV pilus) were also positive by PCR, confirming the DNA homology between CFA III and longus. None of the non-ETEC and non-E. colienteropathogens studied showed the 0.63-kbp amplicon. The procedure thus detected only ETEC strains harboring type IV pili genes with or without other colonization factors. Except for five lngAPCR-positive, probe-positive strains, all lngA PCR-positive strains produced the pilin as demonstrated by immunoblotting. To test the amplification procedure in a clinical setting, a collection of 264 fresh clinical E. coli strains isolated from 88 Mexican children with diarrhea was screened by PCR. Among 82 ETEC isolates found, 30 (36.5%) were lngA PCR-positive. Twenty-seven percent of the children shed ETEC that possessed lngA. In parallel with DNA probes or PCR protocols to detect enterotoxin genes, the lngA PCR method may prove useful for detection of ETEC harboring type IV pilus genes in epidemiological studies.

In the present paper the distribution of peripheral blood T gamma/delta lymphocytes in Graves' disease patients is analyzed in order to correlate them with disease activity and with prognosis. Eighteen patients with Graves' disease, 24 patients with Hashimoto's thyroiditis and 32 sex- and age-matched healthy control subjects were studied. Peripheral blood CD3+ alpha/beta and gamma/delta T lymphocytes as well as CD4+ and CD8+ T cells, and CD19 (B) lymphocytes were analyzed by cytofluorometry. At diagnosis, patients who required a radical treatment for thyrotoxicosis control showed a significant decrease of T gamma/delta lymphocytes and an increase of B cells when compared with those who maintained the euthyroid state after methimazole. No correlation was detected between the percentages of these subpopulations and serum free thyroxine. This decreased proportion did not normalize after methimazole or radical treatments. These results suggest that the cytotoxic T gamma/delta compartment of the immune system is altered in patients with Graves' disease.

To address the question whether there are simple clinical predictors of need for insulin in the first 18 months of treatment of diabetes presenting in young adult subjects, a prospective study of 24 patients with diabetes mellitus (age: 18-40 years) was designed. At diagnosis of diabetes, age, sex, body mass index (BMI), glycemia, ketonuria, C-peptide, insulin autoantibodies, islet cell antibodies and glutamic acid decarboxylase antibodies were recorded before starting any treatment. At the end of the follow-up (18 +/- 4 months), they were divided into two groups according to their need for insulin therapy: group 1 (n=15; 62%), who needed insulin therapy, and group 2 (n=9; 38%), who did not. Each marker was related to actual need for therapy necessity. Multivariate analysis showed that BMI and age were the variables with greatest predictive value regarding need for insulin. These data reveal that the need for insulin therapy in young adult diabetic patients may be supported by the clinical criteria of age and BMI, which are both easily and quickly determined.