Two common and three novel PDS mutations in Thai patients with Pendred syndrome.

Pendred syndrome is an autosomal recessive disorder characterized by congenital sensorineural deafness, goiter, and impaired iodide organification. It is caused by mutations in the PDS gene. Most published mutation studies of Pendred syndrome have dealt with Western populations. In this study, we examined clinical and molecular characteristics of 16 affected individuals in 6 unrelated Thai families. Of all the affected, 100% (16/16) had bilateral deafness, 68.8% (11/16) goiters, and 25% (4/16) hypothyroidism. Follicular thyroid carcinoma and Hürthle cell adenoma were found in affected members of a family, raising the possibility of an increased risk of thyroid carcinoma in Pendred syndrome patients. Sequence analysis of the entire coding region of the PDS gene successfully identified all 12 mutant alleles in these 6 families. The 12 identified mutant alleles constituted 6 distinct mutations including 3 splice site mutations (IVS4-1G>A, IVS7-2A>G, IVS9- 1G>A), one frame shift mutation (1548insC) and 2 missense mutations (T67S, H723R). Eight mutations out of 12 were constituted by IVS7- 2A>G and 1548insC, each one being present in 4 distinct alleles in our studied group. The identification of these two frequent PDS mutations will facilitate the molecular diagnosis of Pendred syndrome in Thai populations. In addition, three newly identified mutations, T67S, IVS4-1G>A, and IVS9-1G>A, were not observed in 50 unrelated healthy Thai controls.

The association between HLA class II haplotype with Graves' disease in Thai population.

The distribution of HLA-DRB1, -DQA1 and -DQB1 alleles were analysed in 124 Graves' disease (GD) patients compared to 124 normal controls in order to identify the alleles/haplotypes associated with GD in Thai population. The DRB1*1602-DQA1*0102-DQB1*0502 haplotype was significantly increased in GD patients (P = 0.0209, OR = 2.55). DRB1*07-DQA1*0201-DQB1*0201 haplotype (P = 0.039, OR = 0.32) and HLA-DRB1*12-DQA1*0601-DQB1*0301 haplotype (P = 0.0025, OR = 0.28) were significantly decreased in GD patients. Interestingly, a protective DRB1*07 allele in Thai population lacks an arginine at position 74 similar to DRB1*0311 (a protective allele in Caucasians). A significant association of DRB1*1602-DQA1*0102-DQB1*0502 and HLA-DRB1*12-DQA1*0601-DQB1*0301 alleles and haplotypes with GD was recently reported in Korean but not in any Caucasian studies. Thus, DRB1*1602 allele and closely linked haplotype, DRB1*1602-DQA1*0102-DQB1*0502, might serve as a marker for genetic susceptibility to GD in Asian population.

Renal and systemic hemodynamics, in falciparum malaria.

Renal and systemic hemodynamics, plasma arginine vasopressin, plasma renin activity, plasma norepinephrine, blood volume and water loading test were studied in 10 patients with falciparum malaria without renal failure. Six patients responded to water load normally, while 4 patients had a decreased response to water load. The patients with a normal water load response had normal renal and systemic hemodynamics and a normal hormonal profile. The patients with a decreased response to water load had hyponatremia, hypervolemia, high cardiac index, low systemic vascular resistance, high plasma arginine vasopressin, high plasma renin activity, high plasma norepinephrine, low creatinine and p-aminohippurate clearances, low urine sodium and high urine osmolality. They had a lower mean arterial pressure during the acute phase of the disease than during the recovery phase. The findings suggest that a decreased response to water load is due to peripheral vasodilatation which results in a decreased effective blood volume leading to the release of vasopressin and norepinephrine, increased renin activity and decreased renal hemodynamics.

Decreased suppressor T-lymphocytes in women who received progestogen injections.

Decreased levels of suppressor T-cells (CD8+) were found in 17 normal women who received progestogen (Depoprovera) injection, 150 mg intramuscularly every three months for contraceptive purposes, for more than 30 months. The helper: suppressor T-cells (CD4+ : CD8+ ratio) was significantly elevated in this group compared to 30 normal female controls. No significant change of T-lymphocyte was found in 53 normal women who received the injection for less than 30 months or who received combined oral contraceptive pills. In conclusion, long term progestogen injection induced a lowering of suppressor T-cell levels, which is the same immunological change found in several autoimmune diseases.

Effects of acute arginine loading on renal and systemic hemodynamics in dogs.

Effects of L-arginine (ARG) infusion on renal and systemic hemodynamics were studied in 12 anesthetized dogs. The experiment was performed in two groups of dogs. The dogs of group 1 (n = 6) received intravenous ARG at 2.5 mmol/kg followed by indomethacin (IND) injection (10 mg/kg) and were rechallenged with ARG at the same amount. The dogs of group 2 (n = 6) received intravenous ARG at 5 mmol/kg followed by IND injection (10 mg/kg) and were later infused with ARG at the same dose. In group 1, the first ARG infusion caused no significant changes in renal and systemic hemodynamics. During the second ARG infusion, glomerular filtration rate (GFR) and renal plasma flow (RPF) were significantly increased when compared with the IND-treated period. In group 2, the first ARG infusion increased cardiac output (CO) and decreased total peripheral resistance (TPR) without significant changes in GFR and RPF. The second ARG infusion induced acute rise of both GFR and RPF approximately twofold, compared with the IND-treated period. CO was also increased significantly. Plasma glucagon levels determined in 2 dogs showed an increase following both ARG infusions. These results indicate that an acute ARG loading induces renal and systemic vasodilatation in a dose-dependent manner despite IND effect, and would indicate that increased renal hemodynamics are not prostaglandin-mediated.

Evaluation of diabetic control by using hemoglobin A1 and fructosamine.

Evaluation of diabetic control was performed by using fasting plasma glucose, hemoglobin A1 and fructosamine in 139 patients with diabetes mellitus, and 36 normal controls. A linear correlation of fasting plasma glucose with fructosamine and hemoglobin A1 was found. Using fasting plasma glucose alone was found to be inadequate to define good control. HbA1 and fructosamine had an acceptable sensitivity and specificity in assessment of diabetic control, although fructosamine was slightly less sensitive than HbA1. In patients with thalassemia, hemoglobin A1 levels were elevated in 18 of 19 patients. Fructosamine levels also gave misleading results since 6 to 19 patients had an elevated level and one patient had a decreased level. Patients with hypoproteinemia had a decreased fructosamine and hemoglobin A1 level compared to normal control. HbA1 and fructosamine should be cautiously interpreted in patients with thalassemia and hypoproteinemic states. Using these methods in combination with other measure such as home monitoring of blood glucose would be more precise particularly in diabetic patients with hypoproteinemia, abnormal hemoglobin and other hemolytic disorders.

Treatment of Graves' disease and the course of ophthalmopathy.

PURPOSE: Contradictory results have been obtained with regards to the effect of various treatment modes on the exacerbation of Graves' ophthalmopathy, probably because the number of patients in each study was small and some studies were analyzed only in relation to one type of treatment. To circument these problems, we studied the course of Graves' ophthalmopathy after various modes of therapy for thyrotoxicosis among 537 patients with Graves' disease. PATIENTS AND METHODS: A total of 537 patients with Graves' disease were prospectively studied over an 11-year period. Thirty-one patients were lost to follow-up during the first six months after treatment and were excluded from the study. Of those remaining, 426 received one form of treatment, 79 received two kinds of therapy, and one received three kinds of therapy. Thus, surgical treatments numbered 164, radioactive iodine-131 (131I) treatments numbered 241, and medical treatments numbered 182. Ocular signs were considered improved or exacerbated by the following criteria: decrement or increment of the exophthalmos of 2 mm or more, improvement or deterioration of visual acuity, and regression or progression of extraocular muscle involvement causing diplopia. RESULTS: Among patients who did not have infiltrative ophthalmopathy before treatment, there was no difference in the occurrence of posttreatment exophthalmos in the surgically, medically, and 131I-treated patients (7.1%, 6.7%, and 4.9%, respectively). The incidence and the degree of progression of ophthalmopathy in patients who already had exophthalmos before treatment were similar in the medically, surgically, and 131I-treated groups (19.2%, 19.8%, and 22.7%, respectively). Most of the progression occurred in the posttreatment euthyroid stage. The incidence of improvement of ophthalmopathy was also similar (14.1%, 12.6%, and 12.3% in the medically, surgically, and 131I-treated patients). CONCLUSION: In conclusion, we found no influence of type of therapy for thyrotoxicosis on the clinical course of Graves' ophthalmopathy in this retrospective study of 537 patients.

Auto-anti-idiotype antibody against anti-thyroglobulin auto-antibody in humans.

Anti-idiotype antibodies (Anti-Id Ab) are believed to normally exert a form of feedback control on Ab production. An abnormality in this network might lead to excess Ab production. To detect the abnormalities in immunoregulation in autoimmune thyroid disease, we tried to demonstrate anti-Id Ab to anti-thyroglobulin antibody (ATA) and to correlate them to the clinical course of disease. We developed two assays, one based on the binding of anti-Id Ab to ATA (Id) and a second on the inhibitory activity of anti-Id Ab in the reaction of human thyroglobulin (hTG) and ATA. We could not demonstrate anti-Id Ab in either assay. Possibly anti-Id Ab to ATA is not formed sufficiently to be detected in our assays, or is only present in specific phases of the course of autoimmune thyroid disease. During studies of anti-Id Ab we found "pepsin site" Ab in patients and normal subjects. We developed a new solid phase radioimmune assay for this Ab, an antibody which reacts with antigens exposed on IgG when F(ab')2 fragments of IgG are prepared. The incidence of this Ab did not differ between patients and normal subjects. IgG from patients with autoimmune thyroid disease which contained high levels of anti-pepsin site Ab, did not show any specificity for ATA (Id), nor did it inhibit the reaction between hTG (Ag) and ATA (Id). The importance of this anti-F(ab')2 antibody remains to be determined, but it does not represent an anti-Id Ab.

Immunoregulatory abnormalities in autoimmune thyroid diseases.

We have investigated the ability of lymphocytes from normal subjects and patients with autoimmune thyroid diseases to respond to a thyroidal antigen (human thyroglobulin, hTG) and a non-thyroidal antigen (Keyhole limpet hemocyanin, KLH) in vitro, using a hapten (trinitrophenol, TNP)-carrier system. This system is based on the concept that the T helper cells which respond to hTG or KLH should stimulate anti-TNP antibody producing B cells in the presence of TNP conjugated hTG (TNP-hTG) or KLH (TNP-KLH). After 5 or 6 days of culture of peripheral blood mononuclear cells with pokeweed mitogen (PWM), PWM and TNP-hTG, or PWM and TNP-KLH, IgM anti-TNP and IgM anti-sheep red blood cell (SRBC) plaque forming cells (PFC) were enumerated. The results showed that (1) in normal controls, hTG caused only suppression in both TNP and SRBC response, and KLH caused dose-related enhancement and suppression in TNP response without a change in SRBC response, and (2) in patients, both hTG and KLH resulted in dose-related enhancement in TNP response without a change in SRBC response. These data suggest that patients with autoimmune thyroid diseases have regulatory cell abnormalities confined to a thyroid antigen.

HLA immunogenetic heterogeneity in black American patients with Graves' disease.

Seventy-three American black patients with Graves' disease were typed for HLA-A, HLA-B, and HLA-DR antigens. There was a slight increase in HLA-DRw6 antigen frequency compared with 238 normal American black controls, but this was not significant after correction for the number of antigens tested. A significant increase in HLA-DR4 and HLA-DRw6 frequency was found in a subgroup of patients with exophthalmos (22.9% and 29.2% compared with 7.6% and 10.1% of normal black controls). There was a significant increase in HLA-DRw6 in a subgroup of patients who were thyroid antibody-positive (26.0%). The increment in HLA-DRw6 was higher in 32 patients who had both exophthalmos and who were antibody positive (37.5%). A significant increase in HLA-DR5 was found in a subgroup of patients who did not have exophthalmos and who were antibody-negative (83.3%). Our findings support previous evidence for immunogenetic heterogeneity in patients with toxic Graves' disease. In American blacks HLA-DRw6 is in some way associated with the disease in contrast to the well-recognized HLA-DR3 association in whites.

Association of differentiated thyroid carcinoma with HLA-DR7.

Seventy-four American white thyroid cancer patients were typed for HLA-A, B, and DR antigens. A significant increase in HLA-DR7 was found in the nonradiation-associated thyroid cancer patients (42.5%, 20/47 cases), compared to 22.8% of 979 normal controls. The association is stronger in the follicular and mixed papillary-follicular subgroup (52.0%, 13/25 cases, P corrected less than 0.01). The occurrence of various malignancies in family members was found in 57.9% of HLA-DR7 positive patients, versus 20% of HLA-DR7 negative patients, in a retrospective record review. Although the frequency of HLA-DR7 was not increased in the radiation-associated thyroid cancer patients (22.2%, 6/27 cases), the interval from the irradiation date to the onset date of thyroid cancer was shorter in HLA-DR7 positive cases (17.3 +/- 6.2 years) than in HLA-DR7 negative patients (29.4 +/- 11.5 years). This data suggest that HLA-DR7 is associated with and may influence development of thyroid cancer.

Cold reactive lymphocytotoxic activity in autoimmune thyroid disease.

An increased incidence of cold-reactive lymphocytotoxic activity (LCTA) has been demonstrated in the sera of patients with autoimmune thyroid disease. Twenty-six of 79 (33%) patients with Graves' disease and 9 of 21 (43%) patients with Hashimoto's thyroiditis had cold-reactive LCTA detected by microcytotoxicity assay compared to 6 of 42 (14%) normal controls. There was no correlation between LCTA and age, sex, MCHA titre or TGHA titre. A positive correlation with FTI and LCTA in Hashimoto's patients was demonstrated, but no such correlation was demonstrable in Graves' patients. The lymphocytotoxic activity was directed preferentially against B cells. There was no preferential lysis of T-cell subsets as defined by monoclonal antibodies, and the lymphocytotoxins were equally reactive with normal lymphocytes and toxic Graves' lymphocytes. The significance of cold-reactive lymphocytotoxic activity in the pathogenesis of autoimmune thyroid disease remains to be determined.

Long-term follow-up study of compensated low-dose 131I therapy for Graves' disease.

We treated 187 patients who had Graves' disease with low-dose radioactive iodide (131I), using a protocol that included a compensation for thyroid size. The incidence of early hypothyroidism (12 per cent) was acceptably low in the first year after 131I treatment, but we found a cumulative high incidence (up to 76 per cent) at the end of the 11th year. In contrast, the incidence of permanent hypothyroidism was relatively stable in 166 surgically treated patients, increasing from 19 to 27 per cent at the end of 11 years. Among 122 medically treated patients, only 40 per cent entered remission, and hypothyroidism developed in 2 per cent during the same period of follow-up. The long-term incidence of hypothyroidism in our patients treated with low-dose 131I therapy was much higher than that found in earlier studies using a comparable dose. Our study suggests that it will be difficult to modify therapy with 131I alone to produce both early control of thyrotoxicosis and a low incidence of hypothyroidism.

T-cell subsets in patients with preeclampsia.

Peripheral blood mononuclear cells from patients with preeclampsia were enumerated by means of monoclonal anti-T-cell antibodies. The percentage of total T cells was significantly decreased in this group of patients, as compared with normal term pregnant women. The low proportion of T cells was due to a proportional reduction in both helper and suppressor T cells; therefore, the ratio of helper to suppressor T cells was not different from that in normal pregnant women. There was no correlation between the degree of reduction in percentage of T cells and severity of the disease. The absolute numbers of T cells were slightly, but not significantly, decreased. Our findings support previous evidence of reduced, not increased, immune reactivity in preeclampsia.

Binding of immunoglobulin-G from patients with thyroid autoimmune disease to normal T lymphocytes.

Sera from patients with Graves' disease and Hashimoto's thyroiditis were reacted with normal T lymphocyte preparations in an attempt to detect binding of immunoglobulin G (IgG) to T cells. Sera from normal subjects and patients with toxic adenomas served as controls. Each serum was reacted with at least three different preparations of normal T cells. Bound IgG was identified using a fluoresceinated second antibody, antihuman IgG. Positive cells were enumerated by means of epifluorescent microscopy. IgG from 57.8% of toxic Graves' patients, 30.7% of Graves' patients who were euthyroid after treatment, and 41.6% of Hashimoto's patients bound to normal T cells more than did IgG from normal controls. Reactivity of toxic adenoma sera was similar to that of normal sera. When the positive sera were reacted with helper or suppressor/cytotoxic T cell preparations (separated by negative selection technique), the binding was shown to be directed against suppressor/cytotoxic T cells but not against helper cells. These data indicate that a significant proportion of patients with autoimmune thyroid disease have IgG in their serum which react with a subset of normal T suppressor/cytotoxic cells. This phenomenon could be the expression of anti-lymphocyte antibodies, which may relate to previously recognized reductions in number and function of suppressor T cells in autoimmune thyroid disease.

Multiple complications of propylthiouracil treatment: granulocytopenia, eosinophilia, skin reaction and hepatitis with lymphocyte sensitization.

An association of granulocytopenia, eosinophilia, skin reaction and hepatitis during propylthiouracil (PTU) therapy for thyrotoxicosis in a 47 year old black female is reported. Clinical and biochemical abnormalities disappeared soon after discontinuation of PTU. That the drug was directly responsible for the observed complications is suggested by the clinical course and by in vitro lymphocyte transformation studies. The latter revealed sensitization to PTU during the acute phase of the disease, which was greatly reduced 5 weeks after discontinuation of the drug and was completely absent after 5 months.