Clinical, biochemical and cytomorphological observations in juvenile chronic lymphocytic thyroiditis.

OBJECTIVE: To determine the clinical, biochemical, ultrasonological and cytomorphological features in goitrous juvenile chronic lymphocytic thyroiditis(CLT). SETTING: Tertiary referral center for thyroid disorders. SUBJECTS: A total of 455 children were evaluated for goiter. Of these 122 children had features of CLT in FNAC and were further studied. METHODS: All subjects were subjected to detailed clinical examination. The thyroid functional status was assessed by estimation of serum concentration of thyroid hormones (thyroxine and triiodothyronine) and thyrotropin (TSH). In addition the antithyroid antibody titers were measured. Ultrasonological and cytomorphological characteristics in these patients were also evaluated. RESULTS: The mean age at presentation was 12.5 years (SD 3.93). The male: female ratio was 1:7.7. Thyroid functional status as assessed by serum thyroxine and thyrotropin levels revealed, euthyroidism in 67 (54.9%), hypothyroidism in 30 (24.6%), subclinical hypothyroidism in 22 (18%) and hyperthyroidism in 3 (2.5%). Thyroid antimicrosomal antibodies were detected in significant titers in 90 (73.8%) and antithyroglobulin was positive in 71 (58.2%). The positivity of the antimicrosomal and antithyroglobulin antibodies were much higher in subjects with hypothyroidism and was detected in 86.5% and 69.2%, respectively. The mean urinary iodine excretion was 74.1 micrograms/g of creatinine (SD 31.4) indicating mild iodine deficiency. Fine needle aspiration cytoloty (FNAC) revealed features of chronic lymphocytic thyroiditis. Hurthle cell changes was seen in only 12% of the cases. The epithelium was more often hyperplastic and vacuolation of the cytoplasm and peripheral vacuolations were seen frequently. Giant cells and epithelioid cells were seen in many cases. CONCLUSIONS: In any child presenting with firm goiter, a diagnosis of CLT should be excluded. Many subjects with juvenile CLT have biochemical evidence of hypothyroidism but only few symptoms or clinical features.

Early development of transient hypothyroidism after I131 therapy for thyrotoxicosis.

295 patients of Graves' disease were studied for early development of transient hypothyroidism (TH) and its prognostic value following I131 therapy. 278 patients received I131 < 10 mci (6.4 +/- 1.7 mci) and 17, a dose of > 10 mci (12.6 +/- 2.6). TH was diagnosed on the basis of low T4 regardless of TSH within the first year after I131 therapy followed by normal T4 and TSH. 32 patients developed TH following administration of < 10 mci I131 and it was symptomatic in 10 patients. No instance of TH after high dose of I131 was noted. I131 uptake > 60% at 2 hours before treatment was a risk factor for developing TH (odds ratio 2.6, 95% confidence interval 0.8-9.6). At diagnosis of TH basal TSH was high in 53%, normal in 32%, or low in 15%; Hypothyroidism recognized during the first six months with basal TSH of 50 microU/ml or higher ruled out TH. Development of TH and its hormonal profile did not influence long term thyroid functions. As no prognostic factors predicted TH before I131 therapy or at the time of diagnosis, re-evaluation of thyroid functions later is essential to avoid unnecessary chronic replacement therapy, if hypothyroidism has been diagnosed within a few months of I131 treatment.

Prognostic significance of thyroid antibodies in hyperthyroid patients treated with antithyroid drugs.

Lymphocytic infiltration of the thyroid gland in patients with hyperthyroidism is associated with the presence of serum antithyroidal microsomal antibodies (TMA) and serum antithyroglobulin antibodies (TGA). The aim of this study was to evaluate the clinical significance of TMA and TGA during and after treatment of hyperthyroidism with antithyroidal drugs. One hundred and fifty-four hyperthyroid patients were treated for 18 months with methimazole and then followed up for 18 months or more (mean, 24.8 +/- 12.6 months). Patients were classified into three group. group I, patients negative for TGA and TMA before and during 18 months of treatment, group II patients positive for TMA but negative for TGA before and during 18 months treatment and group III patients who were positive for both TGA and TMA before and during treatment. The relapse rates after discontinuation of treatment in these group were 44.7% (17 of 38), 29% (18 of 62) and 11.1% (6 of 54), respectively. The value in group I was significantly higher than that in group III (P < 0.01). These results show that presence of TMA and TGA influence the prognosis of patients with hyperthyroidism treated with methimazole with regard to relapse. Those patients who had both antibodies were least likely to have a relapse and those who had neither antibody before and during treatment were most likely to have a relapse of hyperthyroidism.

Iodine loss from iodised salt on heating.

Iodine deficiency disorders constitute a major public health problem in India. The national IDD control programme (NIDDCP) relies solely on iodine supplementation through fortification of common salt with potassium iodate. However, data regarding iodine loss due to high temperatures of cooking procedure is scarce. Using iodometric titration methods, we calculated iodine content of iodised salt samples subjected to incremental heat up to 350 degree Celsius. The results of the study indicate a gradual but minimal loss of iodine content from the iodised salt samples when subjected to high temperature with a maximum loss noticed being 18.5% at 350 degree Celsius. We conclude that there is minimal loss of iodine from the salt fortified with potassium iodate when subjected to heating (temperature normally attained during cooling process).

Evaluation of long-term results of two schedules of treatment for toxic multinodular goitre with radioiodine therapy (I 131).

Results of the long term effects of two schedules of radioine therapy (I131) in 130 toxic multinodular goitre patients were evaluated. Seventy five patients (group I) were treated with low doses and 55 patients (group II) with calculated high doses adjusted for thyroid weight (0.5-1 mu ci/g) and radioiodine uptake. Follow up (mean +/- SEM) was 4.5 +/- 0.4 years and 4.8 +/- 0.6 years respectively (p > 0.1). At the end of followup hyperthyroidism was successfully reversed in 87% (Group I) and 82% (Group II). In group I hypothyroidism was present in 5% of patients while it was 12.5% in group II patients. The total dose per gram of thyroid tissue was not significantly different in both the groups (0.058 mu ci +/- 0.0054 VS 0.073 +/- 0.0054 ci/g.) However in group II the number of I131 administration was significantly lower (1.5 +/- 0.2) than in group I (3.2 +/- 0.4) and the percentage of patients who were adequately treated in Group II with single dose was more as compared in group I (62% in group II versus 49% in group I) Hypothyroidism was reached in a shorter time after treatment in group II (median time 0.8 year in group II Vs 1.1 yrs in group I). Patients with positive thyroid antibodies showed a significant earlier development of hypothyroidism within six months. It is concluded that radioiodine is an effective treatment for toxic multinodular goitre with a significant low incidence of post therapy hypothyroidism in patients treated with low doses as compared to higher doses of radioiodine therapy.