Does a highly sensitive thyroglobulin (Tg) assay change the clinical management of low-risk patients with thyroid cancer with Tg on T4 < 1 ng/ml determined by traditional assays?

OBJECTIVE: To evaluate a highly sensitive thyroglobulin (Tg) assay [functional sensitivity (FS): 0.1 ng/ml] (Tg-ICMA) in low-risk patients with known Tg on T4 < or = 1 ng/ml measured by a traditional assay (FS: 1 ng/ml) (Tg-IRMA). METHODS: Tg-ICMA was measured in serum samples stored at -70 degrees C. Samples were obtained 6 months or more after total thyroidectomy and remnant ablation with (131)I, during L-T4 therapy (TSH < 0.4 mIU/l). All patients had well-differentiated and completely resected tumours, no ectopic uptake on post-therapy whole-body scans and were considered to be at low risk for recurrence. On the occasion of collection and retesting for this study, Tg-IRMA was < or = 1 ng/ml in all samples and no antibody interference was observed. RESULTS: Tg-ICMA < or = 0.1 ng/ml was observed in 130/178 (73%) patients and recurrence was diagnosed in only 1/130 (0.8%). Tg-IRMA measured after L-T4 withdrawal was > 1 ng/ml in 5/130 (3.8%) patients. Forty-eight (27%) patients had Tg-ICMA > 0.1 ng/ml (0.12-1.6 ng/ml) and recurrence was diagnosed in 5/48 (10.5%). Tg-IRMA measured after L-T4 withdrawal was > 1 ng/ml in 20/48 (41.6%) patients. A negative predictive value of 100% was achieved with Tg-ICMA on T4 < or = 0.1 ng/ml combined with neck ultrasonography (US) or with stimulated Tg-IRMA < or = 1 ng/ml. CONCLUSIONS: Patients at low risk for recurrence with undetectable Tg on T4 measured by a highly sensitive assay (FS: 0.1 ng/ml) in the absence of antibody interference and with a negative sensitive neck US do not need to be submitted to Tg stimulation. Recurrence is rare in these cases and only a minority of patients convert to stimulated Tg > 1-2 ng/ml.

Ovarian function after radioiodine therapy in patients with thyroid cancer.

OBJECTIVE: To assess ovarian function in young women treated with radioiodine. METHODS: The study was conducted on 50 women with thyroid carcinoma aged less than 40 years (mean, 29.8 years), with regular menstrual cycles and normal FSH levels prior to radioiodine therapy. FSH determination was repeated 6 and 12 months after radioiodine therapy (mean, 4.24 GBq iodine-131) and menstrual cycles were monitored during this period. RESULTS: Twenty percent of the patients reported amenorrhea during the first year. FSH levels increased after 6 months (from 5.1 +/- 1.8 to 10.6 +/- 2.2 IU/l, p < 0.00 001) and 28 % of the patients showed elevated values, which had returned to normal by the end of the first year. CONCLUSION: Radioiodine causes transitory alterations in ovarian function even in younger women and after a mean activity of 4.2 GBq (115 mCi).

Fetal hemoglobin levels are related to metabolic control in diabetic subjects.

We have investigated the relationship between fetal hemoglobin (HbF) levels and metabolic control in subjects with insulin-dependent (N = 79) and non-insulin-dependent diabetes mellitus (N = 242). HbF and hemoglobin A1c (HbA1c) levels were increased in subjects with type 1 and type 2 diabetes as compared to levels in nondiabetic individuals (P < 0.0001), and were significantly higher in type 1 than in type 2 diabetes subjects. Lower levels of HbA1c and HbF were observed in type 2 diabetes subjects treated by diet, intermediate levels in those treated with oral hypoglycemic agents, and higher levels in those treated with insulin. HbF and HbA1c levels were correlated in type 1 diabetes (R2 = 0.57, P < 0.0001) and type 2 diabetes (R2 = 0.58, P < 0.0001) subjects. Following intense treatment, twelve diabetic patients showed significant improvement both in HbA1c and HbF values. We conclude that increased HbF levels reflect poor metabolic control in subjects with diabetes mellitus.

Fetal hemoglobin levels are related to metabolic control in diabetic subjects

We have investigated the relationship between fetal hemoglobin (HbF) levels and metabolic control in subjects with insulin-dependent (N = 79) and non-insulin-dependent diabetes mellitus (N = 242). HbF and hemoglobin A1c (HbA1c) levels were increased in subjects with type 1 and type 2 diabetes as compared to levels in nondiabetic individuals (P<0.0001), and were significantly higher in type 1 than in type 2 diabetes subjects. Lower levels of HbA1c and HbF were observed in type 2 diabetes subjects treated by diet, intermediate levels in those treated with oral hypoglycemic agents, and higher levels in those treated with insulin. HbF and HbA1c levels were correlated in type 1 diabetes (R2 = 0.57, P<0.0001) and type 2 diabetes (R2 = 0.58, P<0.0001) subjects. Following intense treatment, twelve diabetic patients showed significant improvement both in HbA1c and HbF values. We conclude that increased HbF levels reflect poor metabolic control in subjects with diabetes mellitus.

Specific insulin and proinsulin secretion in glucokinase-deficient individuals.

Glucokinase (GCK) is an enzyme that regulates insulin secretion, keeping glucose levels within a narrow range. Mutations in the glucokinase gene cause a rare form of diabetes called maturity-onset diabetes of the young (MODY). An early onset (less than 25 years), autosomal dominant inheritance and low insulin secretion stimulated by glucose characterize MODY patients. Specific insulin and proinsulin were measured in serum by immunofluorimetric assays (IFMA) during a 75-g oral glucose tolerance test (OGTT). Two kindreds (SA and LZ) were studied and compared to non-diabetic unrelated individuals (control group 1) matched for age and body mass index (BMI). In one kindred, some of these subjects were also obese (BMI > 26 kg/m2), and other family members also presented with obesity and/or late-onset NIDDM. The MODY patients were also compared to a group of five of their first-degree relatives with obesity and/or late-onset NIDDM. The proinsulin profile was different in members of the two MODY kindreds. Fasting proinsulin and the proinsulin/insulin ratio were similar in MODY members of kindred LZ and subjects from control group 1, but were significantly lower than in MODY members of kindred SA (P < 0.02 and P < 0.01, for proinsulin and proinsulin/insulin ratio, respectively). Moreover, MODY members of family SA had higher levels of proinsulin and proinsulin/insulin ratio, although not significantly different, when compared to their first-degree relatives and to subjects from control group 2. In conclusion, we observed variable degrees of proinsulin levels and proinsulin/insulin ratio in MODY members of two different kindreds. The higher values of these parameters found in MODY and non-MODY members of kindered SA is probably related to the obesity and late-onset NIDDM background present in this family.

Specific insulin and proinsulin secretion in glucokinase-deficient individuals

Glucokinase (GCK) is an enzyme that regulates insulin secretion, keeping glucose levels within a narrow range. Mutations in the glucokinase gene cause a rare form of diabetes called maturity-onset diabetes of the young (MODY). An early onset (less than 25 years), autosomal dominant inheritance and low insulin secretion stimulated by glucose characterize MODY patients. Specific insulin and proinsulin were measured in serum by immunofluorimetric assays (IFMA) during a 75-g oral glucose tolerance test (OGTT). Two kindreds (SA and LZ) were studied and compared to non-diabetic unrelated individuals (control group 1) matched for age and body mass index (BMI). In one kindred, some of these subjects were also obese (BMI>26 kg/m2), and other family members also presented with obesity and/or late-onset NIDDM. The MODY patients were also compared to a group of five of their first-degree relatives with obesity and/or late-onset NIDDM. The proinsulin profile was different in members of the two MODY kindreds. Fasting proinsulin and the proinsulin/insulin ratio were similar in MODY members of kindred LZ and subjects from control group 1, but were significantly lower than in MODY members of kindred SA (P<0.02 and P<0.01, for proinsulin and proinsulin/insulin ratio, respectively). Moreover, MODY members of family SA had higher levels of proinsulin and proinsulin/insulin ratio, although not significantly different, when compared to their first-degree relatives and to subjects from control group 2. In conclusion, we observed variable degrees of proinsulin levels and proinsulin/insulin ratio in MODY members of two different kindreds. The higher values of these parameters found in MODY and non-MODY members of kindred SA is probably related to the obesity and late-onset NIDDM background present in this family.

[Cutis laxa associated to cardiac failure] / Cutis Laxa associada à insuficiência cardíaca congestiva.

OBJECTIVE: To focus attention on a rare pathology of the childhood which presents premature aging of the skin and can be lethal. METHODS: The authors present a case of cutis laxa, syndrome of premature aging, in an eight year-old child, and discuss the classification, diagnosis and prognosis of the disease. RESULTS: The child presented signs of premature aging when he was four years-old. The diagnosis of cutis laxa was confirmed by skin biopsy. The patient presented heart failure, a systemic complication different from those previously described, and died at eight years of age. CONCLUSIONS: The importance of the diagnosis of cutis laxa resides in the fact that besides characteristic dermatological findings, there are frequent systemic complications that can be the focus of preventive measures, since there is no specific treatment for this disease. Genetic counseling is another important issue in this condition.

Leptin levels, beta-cell function, and insulin sensitivity in families with congenital and acquired generalized lipoatropic diabetes.

Lipoatropic diabetes (LD) designates a group of syndromes characterized by diabetes mellitus with marked insulin resistance and either a localized or generalized absence of adipose tissue. In this study, we evaluated plasma leptin levels in subjects with congenital generalized lipoatropic diabetes (CGLD, n = 11) or acquired generalized lipoatropic diabetes (AGLD, n = 11), and assessed correlations between leptin levels and estimations of insulin secretion and insulin sensitivity using homeostasis model assessment (HOMA). Leptin levels were 0.86 +/- 0.32, 1.76 +/- 0.78, and 6.9 +/- 4.4 ng/mL in subjects with CGLD, AGLD, and controls (n = 19), respectively (ANOVA P < 0.0001). Specific insulin levels were 154 +/- 172, 177 +/- 137 and 43 +/- 22 pmol/L, respectively (P < 0.0001). Insulin sensitivity was significantly decreased in both groups with LD (P < 0.0001), whereas HOMA beta-cell function was not significantly different when compared with controls. Leptin levels were significantly correlated with body mass index, insulin levels, and HOMA beta-cell function, and inversely correlated with insulin sensitivity in control subjects but not in subjects with generalized LD. In conclusion, decreased leptin levels were observed in subjects with generalized LD, with a trend towards lower levels in the acquired than in the congenital form (P = 0.06). The temporal relationship between the decrease in leptin levels and the development of lipoatrophy should be investigated in at-risk young relatives of subjects with the acquired forms to assess the usefulness of leptin levels as a marker of lipoatrophy.