Biomedical subjects

Arthur B Parkes

Publications and source records attributed to Arthur B Parkes.

4 recordsLinked to original sources

PubMed2005

Thyroglobulin antibodies in serum of patients with differentiated thyroid cancer: relationship between epitope specificities and thyroglobulin recovery.

BACKGROUND: Serum antibodies against thyroglobulin (TgAbs) are common in patients with differentiated thyroid cancer (DTC) and can interfere in thyroglobulin (Tg) assays. We identified the epitopes on Tg recognized by TgAb-positive sera from patients with DTC and examined the association between epitope specificity patterns and Tg recovery. METHODS: We tested 50 DTC sera for Tg epitope specificity, TgAbs, and Tg recovery. Epitope recognition was determined by use of a panel of 10 well-characterized Tg monoclonal antibodies directed against 6 Tg antigenic clusters (I-VI) in competitive reactions with test sera. Tg was measured by the Thyroglobuline IRMA (CIS bio international). Recovery of added Tg (TgREC) was determined by an in-house assay. RESULTS: Epitope recognition was restricted to immunodominant clusters in 58% of patients, whereas the rest were either broadly heterogeneous (16%) or nonreactive (26%). Median Tg recovery did not differ between sera with restricted and unrestricted specificities (69% vs 80%; P >0.05). TgREC was inversely correlated with the total number of epitopes recognized by sera (r = -0.66; P <0.001). CONCLUSIONS: TgAbs with both restricted and broad specificities are present in patients with DTC. TgAb interference is related to the number of epitopes recognized by sera rather than the pattern of epitope recognition.

Adolescent↗

PubMed2005

In vivo and in vitro effects of statins on lymphocytes in patients with Hashimoto's thyroiditis.

BACKGROUND: Statins have apoptotic effects on many cell types. Hashimoto's thyroiditis (HT) is an autoimmune disease in which cell-mediated autoimmune mechanisms are pathogenetically involved. OBJECTIVE: The aim of this study was to evaluate the in vivo effects of Simvastatin on thyroid function, lymphocyte subtypes and also to investigate the apoptotic effects of Simvastatin, Mevastatin, Pravastatin and Cerivastatin on lymphocytes from patients with HT. METHODS: In the first part of the study, 11 patients with HT and subclinical hypothyroidism (SH) were given Simvastatin (20 mg/day) for 8 weeks. Ten patients with SH and HT served as the control group. No treatment was given to controls. Thyroid function, C-reactive protein (CRP) levels and lymphocyte subtypes of both groups were determined before the study and after 8 weeks. In the second part of the study, the apoptotic effects of statins on lymphocytes were evaluated in patients with HT (n = 10) and normal subjects (n = 10) in vitro. Apoptosis was investigated by using Annexin-V and propidium iodide. Lymphocytes from patients and controls were incubated with different concentrations of Simvastatin, Cerivastatin, Mevastatin and Pravastatin. RESULTS: An increase in serum free tri-iodothyronine and free thyroxine levels and a decrease in TSH levels were observed (P < 0.05) with Simvastatin treatment. CD4+ cells and B lymphocytes increased whilst CD8+ cells, natural killer cells and activated T lymphocytes decreased significantly in the treatment group (P < 0.05). The CRP level of the group also decreased with Simvastatin but it did not reach significance (P = 0.057). None of parameters was found to be different from the baseline in the control group. In in vitro experiments, apoptosis was observed in CD3 + (both in CD8+ and CD4+ cells) with all statins in both patient and control samples. Mevalonate, which was used in experiments, reversed apoptosis in some but not all samples. CONCLUSIONS: The results of this study suggested that Simvastatin is an immune modulatory agent and improves thyroid function in patients with HT. This effect is probably mediated via lymphocyte apoptosis as demonstrated with in vitro experiments and is not confined to Simvastatin since Mevastatin, Pravastatin and Cerivastatin also induced apoptosis in lymphocytes.

Adult↗

PubMed2003

The prevalence of elevated serum C-reactive protein levels in inflammatory and noninflammatory thyroid disease.

C-reactive protein (CRP) levels have not been routinely used to diagnose thyroid disease, although many thyroid conditions involve inflammation. This study was intended to determine whether CRP levels could differentiate between inflammatory and noninflammatory thyroid conditions, especially between type II inflammatory amiodarone-induced thyrotoxicosis (AIT) and type I iodine-induced AIT. Serum high-sensitivity CRP levels were measured in 100 euthyroid controls (7 taking amiodarone) and 353 patients with one of the following thyroid conditions: AIT, subacute thyroiditis, toxic diffuse goiter, nodular goiter, Hashimoto's thyroiditis, shortterm hypothyroidism, or postpartum thyroiditis. No patients with nontoxic multinodular goiter (n = 34), toxic nodular goiter (n = 23), or toxic diffuse goiter, either untreated (n = 49) or euthyroid while taking methimazole (n = 33), had positive CRP levels (>10 mg/L). The occurrence of positive CRP levels among patients with Hashimoto's thyroiditis (n = 35), short-term hypothyroidism (n = 38), and postpartum thyroiditis (n = 70) did not differ significantly from controls. The occurrence of positive CRP values did not differ significantly between patients with type I and type II AIT and controls. Six of 7 patients (86%) with untreated subacute thyroiditis had positive CRP levels (p < 0.00001). These results indicate that there is only a limited role for measurement of CRP levels in the diagnosis of thyroid diseases other than subacute thyroiditis.

Adolescent↗

PubMed2003

Is there an association between life events, postnatal depression and thyroid dysfunction in thyroid antibody positive women?

BACKGROUND: Postnatal depression is more common in women positive for thyroid autoantibodies, independent of thyroid hormone dysfunction, but the basis of this association is unclear. AIMS: The objective of the work reported here has been to investigate from data obtained from previously published research, a possible association between life events, postnatal depression and the development of thyroid dysfunction in women who are positive for thyroid autoantibodies. METHOD: A cohort of pregnant women whose thyroid antibody status was positive (N = 115), was identified at antenatal booking (approximately 16 weeks). These, and a group of women negative for thyroid antibodies (N = 123), were assessed for depression at six to eight weeks postpartum and then at 12, 20 and 28 weeks postpartum according to Research Diagnostic Criteria (RDC). The number and type of life events over the preceding year were also assessed at eight weeks postpartum using Paykel's Life Event Schedule. At four weekly intervals post-partum until six months, thyroid antibody levels and thyroid function (plasma T3 T4 and TSH) were measured. RESULTS: As anticipated, the thyroid antibody status remained the same throughout the study, and there was no difference in the number or type of life events reported in the preceding year, between antibody positive and antibody negative women. Postnatal depression was associated with an excess of both total and negative life events, independent of thyroid antibody status or actual thyroid hormonal status. Women who developed thyroid dysfunction did not report an excess of life events (total, negative or neutral) in the preceding year. CONCLUSION: There was an excess of reported total and negative life events in women with postnatal depression, but this was independent of thyroid antibody status or function.

Autoantibodies↗