Subclinical hypothyroidism and deep venous thrombosis. A pilot cross-sectional study

Several in-vivo studies have shown a procoagulant state in both overt and subclinical hyperthyroidism and in subclinical hypothyroidism. Insofar, no clinical studies have ever evaluated the relationship between thyroid dysfunction and clinically deep venous thrombosis (DVT). A pilot cross-sectional study aimed at assessing the frequency of overt and subclinical thyroid dysfunction patients with DVT was carried out. Fifty consecutive adult outpatients with a previous diagnosis of provoked DVT (pDVT), and 50 consecutive adult outpatients with a previous diagnosis unprovoked DVT (unDVT), both of the lower legs, who were followed at the Thrombosis Unit of the University Hospital of Varese, Italy, were enrolled after written informed consent. Fifty subjects, in whom such a diagnosis could be ruled out, served as controls. In each patient serum free thyroxine (FT4), free triiodothyronine (FT3), thyrotropin (TSH), anti-thyroid peroxidase (AbTPO), and anti-thyroglobulin (AbTg) antibodies were assayed. Previously unrecognised subclinical hypothyroidism was diagnosed in seven (14.0%) unDVT patients, one (2%) pDVT patient, and one (2%) control (odds ratio at multivariate analysis, 5.54; 95% confidence interval, 0.6-52.6); one new case of subclinical hyperthyroidism was diagnosed in each group; only one case (in the control group) of clinical overt hyperthyroidism was observed. The prevalence of thyroid autoantibodies, including both euthyroid and subclinical hypothyroid patients, did not differ in the three groups. The results of this pilot study suggest an increased prevalence of subclinical hypothyroidism in patients with unDVT. The clinical relevance of these preliminary findings needs to be addressed in larger prospective studies.

Glucocorticoid response in amiodarone-induced thyrotoxicosis resulting from destructive thyroiditis is predicted by thyroid volume and serum free thyroid hormone concentrations

CONTEXT

Amiodarone-induced thyrotoxicosis (AIT) resulting from destructive thyroiditis (type 2) is commonly treated with glucocorticoids, but time needed to restore euthyroidism may be unacceptable for patients with underlying cardiac disorders.

OBJECTIVE

The objective of this prospective study was to identify factors affecting the response to glucocorticoids in a large cohort of patients with type 2 AIT followed prospectively.

SETTING

This study was conducted at university centers.

PATIENTS

Sixty-six untreated patients with type 2 AIT were enrolled in the study.

INTERVENTION

All patients were treated with prednisone (initial dose, 0.5 mg/kg.d) as long as needed to restore euthyroidism, defined as cure of AIT.

MAIN OUTCOME MEASURE

The main outcome measure was cure time.

RESULTS

The median cure time was 30 d (95% confidence interval, 23-37 d). Serum free T4 concentration (picograms per milliliter) and thyroid volume (milliliters per square meter) (and, to a lesser extent, serum free T3 concentration) at diagnosis were the main determinants of response to glucocorticoids, with a cure hazard ratio of 0.97 (95% confidence interval, 0.95-0.99; P = 0.005) and 0.84 (95% confidence interval, 0.77-0.91; P = 0.000) for unit of increment, respectively. AIT was cured in all patients with a complete follow-up; euthyroidism was reached in 30 d or less in 60% of patients but in more than 90 d in 16%. A prompt control of thyrotoxicosis (<or=30 d of treatment) was more frequent (77%) in patients with serum basal free T4 concentration no greater than 50 pg/ml and thyroid volume (normalized for body surface area) no greater than 12 ml/m2. The cure probability and the mean cure time in an individual patient can be obtained using a formula generated by multiple regression models.

CONCLUSIONS

Baseline serum thyroid hormone concentrations and thyroid volume help identify patients with type 2 AIT at risk of a delayed response to glucocorticoids.

Abnormal expression of PPAR gamma isoforms in the subcutaneous adipose tissue of patients with Cushing's disease

BACKGROUND

Obesity is a clinical feature of patients with Cushing's disease. Peroxisome proliferators-activated receptor (PPAR)gamma is the master regulator of adipogenesis; however, the expression of PPARgamma isoforms in the subcutaneous adipose tissue (SAT) of patients with Cushing's disease is unknown.

AIM AND METHODS

The expression of PPARgamma1 and PPARgamma2 was evaluated by real-time reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence (PPARgamma2 only) in SAT samples of 7 patients with untreated active Cushing's disease (Cushing(UNTR)), 8 with Cushing's disease in remission (Cushing(REM)) after pituitary adenomectomy, 15 normal lean subjects (Control(LEAN)), and 15 obese patients (Control(OBE)).

RESULTS

Control(LEAN) had a higher degree of PPARgamma1 than PPARgamma2 (PPARgamma2/PPARgamma1 ratio, 0.55 +/- 0.35). PPARgamma2/PPARgamma1 ratio decreased in Cushing(UNTR) (0.10 +/- 0.043, P < 0.03 vs. Control(LEAN) and Control(OBE)), because of either increased PPARgamma1 or reduced PPARgamma2 expression. PPARgamma2/PPARgamma1 ratio was 0.48 +/- 0.07 in Cushing(REM) patients (P < 0.04 vs. Cushing(UNTR), P < 0.03 vs. Control(OBE)). PPARgamma2/PPARgamma1 ratio was higher in Control(OBE) 0.90 +/- 0.38 than in Control(LEAN) (P < 0.005 vs. Control(LEAN), P < 0.03 vs. Cushing(REM), P < 0.009 vs. Cushing(UNTR)). PPARgamma2/PPARgamma1 ratio was related to serum cortisol levels only in patients with Cushing'disease (r = 0.688, P < 0.02).

CONCLUSIONS

Cushing(UNTR) patients had an abnormal expression of PPARgamma isoforms in SAT related to serum cortisol levels. Although further studies are necessary, it is conceivable that variations in the expression of PPARgamma isoforms might have a role in the abnormal adipogenesis of patients with Cushing's disease.

Changes in autonomic modulation to the heart and intracellular catecholamines. A longitudinal study in differentiated thyroid carcinoma during short-term hypothyroidism and thyroid hormone replacement

BACKGROUND

The effects of thyroid deprivation on the autonomic modulation to the heart remain controversial.

METHODS

In this study in patients followed for thyroid carcinoma, we investigated (1) heart rate variability parameters and the baroreflex gain and (2) intracellular catecholamine levels in circulating lymphocytes during short-term hypothyroidism (phase 1) and after reinstitution of TSH-suppressive thyroid hormone replacement (phase 2).

RESULTS

The RR interval value (p < 0.01) and systolic blood pressure (p < 0.05) were higher in phase 1 than in phase 2. The low-frequency/high-frequency (LF/HF) ratio was significantly lower in the hypothyroid state (p < 0.05), with a higher HF component (p < 0.05). After adjusting for mean RR interval in the regression model, the difference between the power of RR interval oscillations calculated in the two states was greater for the LF band (p = 0.005) and it was borderline significant for the HF band (p = 0.052). The baroreflex gain alpha(LF) index was similar in the two phases. The stimulus-induced cellular production of norepinephrine and epinephrine in peripheral blood mononuclear cells was significantly higher in phase 2.

CONCLUSION

The neurally-mediated influences on the sinus node and the study of intracellular catecholamine production suggest a reduced sympathoexcitation in hypothyroidism compared with the treatment phase. The early increase in blood pressure observed after thyroid hormone withdrawal is not due to impaired sensitivity of the baroreflex arc.

Management of amiodarone-induced thyrotoxicosis in Latin America: an electronic survey

OBJECTIVE

To assess diagnostic and therapeutic approaches to amiodarone-induced thyrotoxicosis (AIT) among members of the Latin American Thyroid Society (LATS).

METHODS

LATS members responded to an online questionnaire that presented an index case (a 62-year-old man on amiodarone, with thyrotoxic symptoms and a nodular goitre) and a variant (same patient, no goitre).

RESULTS

About 25% of invited members responded to the questionnaire. Most respondents lived in iodine-sufficient areas and observed that amiodarone-induced hypothyroidism (AIH) is more common than AIT. Nearly all assessed TSH, and the most used combination of tests was TSH and free T4 (37%). Thyroid autoimmunity was assessed by about 90%. Interleukin-6 (IL-6) was useful to 80%. Additional tests ordered for the index case were: radioactive iodine uptake (RAIU; 57%), echo-colour Doppler sonography (ECDS; about 50%) and fine-needle aspiration biopsy (FNAB; 44%). For the variant, ECDS and RAIU were judged unhelpful by 16%. Most defined the index case as type I AIT and the variant as type II AIT, but 16% in LATS suggested a mixed form in the index case. As initial treatment, nearly all used thionamides in the index case [with potassium perchlorate (KClO(4)) in one-third], while glucocorticoids were indicated to the variant by 66%. Only about 5% considered amiodarone withdrawal unnecessary. If initial strategy is ineffective in type I AIT, KClO(4) (half) or glucocorticoids (a third) are added; in type II, glucocorticoids are indicated by most. Once euthyroidism is restored, ablative therapy is prescribed by a third of respondents for type I AIT.

CONCLUSIONS

There are several points of disagreement among thyroidologists regarding AIT management, mainly in the radiological evaluation and the approach to the already stabilized patient if amiodarone needs to be restarted.

Thyroid color flow Doppler sonography: an adjunctive tool for differentiating patients with inappropriate thyrotropin (TSH) secretion due to TSH-secreting pituitary adenoma or resistance to thyroid hormone

BACKGROUND

Thyrotropin (TSH)-secreting pituitary adenoma (TSHoma) and resistance to thyroid hormone (RTH) are two forms of inappropriate TSH secretion. Thyroid blood flow is largely TSH dependent.

OBJECTIVE

To assess whether thyroid blood flow may help to differentiate TSHoma and RTH.

DESIGN

Intrathyroidal color flow Doppler sonography (CFDS) pattern and peak systolic velocity (PSV) were assessed at baseline and during T(3) suppression test on eight consecutive patients with TSHoma and 10 with RTH.

MAIN OUTCOME

All controls had CFDS pattern 0. Three RTH patients had pattern I and seven had pattern II. Two TSHoma patients had pattern I, five had pattern II, and one had pattern III. PSV at baseline was 3.8 +/- 1.3 cm/s in controls, 8.8 +/- 2.5 cm/s in RTH, 11.1 +/- 2.7 cm/s in TSHoma (p < 0.0003 vs. controls, p = 0.087 RTH vs. TSHoma). After T3 suppression test, PSV values were lower in RTH than in TSHoma (4.6 +/- 1.8 vs. 7.7 +/- 2.6 cm/s, p = 0.008). PSV values and CFDS pattern normalized in nine and eight RTH patients, respectively, after T(3) suppression test; conversely, only one TSHoma patient had a normalization of PSV values, and none had a normalization of CFDS pattern (p < 0.003 vs. RTH).

CONCLUSIONS

Both RTH and TSHoma have increased CFDS pattern and PSV values; however, after T(3) both parameters normalized in most patients with RTH but not in those with TSHoma. Accordingly, CFDS pattern and PSV are adjunctive tools to differentiate these two forms of inappropriate TSH secretion.

Early assessment of visual information processing and neurological outcome in preterm infants

Psychological tests based on visual information processing have shown to be promising in predicting neurodevelopmental outcome in infants at risk. In the present study we prospectively investigated the early development in a group of 20 high-risk preterm infants by means of i) the Fagan Test of Infant Intelligence at 7, 9, and 12 months postterm and ii) a detailed battery for the early assessment of visual functions at 6 and 10 months postterm. The results were then correlated to the Griffiths development scales at two years. At around 7 months no correlation was found in our infants between the Fagan test and neurodevelopmental outcome, possibly as a consequence of the influence of abnormal oculomotor behaviour. At around 9 months most of the visual abnormalities were no more present and the Fagan test was significantly correlated with the outcome. At 12 months postterm a decline of the predictive value of the FTII was observed. In conclusion, nine months postterm age appears to be the best age for the early assessment of neurodevelopmental outcome in high-risk preterm infants, as the maturation of the attentional and visual systems allows a more reliable evaluation.

Long-term outcome of thyroid function after amiodarone-induced thyrotoxicosis, as compared to subacute thyroiditis

BACKGROUND

Two main forms of amiodarone- induced thyrotoxicosis (AIT) exist: type 1 AIT is a condition of true hyperthyroidism developing in patients with pre-existing thyroid disorders, and usually requires thyroid ablative treatment. On the other hand, type 2 AIT is a form of destructive thyroiditis occurring in normal thyroids, the management of which usually consists in glucocorticoid treatment.

AIM

To assess the long-term outcome of thyroid function in a prospective study of type 2 AIT patients, as compared to patients with De Quervain's subacute thyroiditis (SAT).

PATIENTS AND METHODS

Sixty consecutive patients with type 2 AIT were evaluated during oral glucocorticoid treatment (oral prednisone 30 mg/day, gradually tapered and withdrawn over a 3-month period) and followed for 38+/-4 months (range 6-72) thereafter. Sixty consecutive patients with SAT, referred to our Institutes during the same period and treated with the same therapeutic schedule, served as controls.

RESULTS

Type 2 AIT patients were older (p<0.0001) and showed a larger male preponderance (M:F 3.6:1 vs 0.5:1, p<0.0001) than SAT patients. Mean serum free T4 (FT4) and free T3 (FT3) concentrations at diagnosis were increased in both conditions, but higher in type 2 AIT than in SAT (FT4 47.6+/-18.8 and 29.6+/-8.3 pmol/l, respectively, p<0.0001; FT3 15.4+/-7.0 and 11.2+/-3.0 pmol/l, respectively, p<0.001). Correction of thyrotoxicosis was obtained in all patients in both groups, but restoration of euthyroidism occurred earlier in SAT than in type 2 AIT (p=0.006). Ten type 2 AIT patients (17%) and 3 SAT patients (5%, p<0.03) became permanently hypothyroid after glucocorticoid withdrawal and required levothyroxine replacement.

CONCLUSIONS

A relevant proportion of type 2 AIT patients develop permanent hypothyroidism after correction of thyrotoxicosis. Thus, periodic surveillance of thyroid status is required after type 2 AIT.

The reduction of bone mineral density in postmenopausal women with primary hyperparathyroidism is higher in the presence of concomitant GH secretion impairment

OBJECTIVE

To investigate, in a large group of postmenopausal primary hyperparathyroidism (PHP) women, whether the concomitance of GH deficiency (GHD) may contribute to the development of changes in bone mineral density (BMD).

DESIGN

GH secretion, bone status and metabolism were investigated in 50 postmenopausal women with PHP and in a control group of 60 women with no evidence of PHP, matched for age, age at menopause and body mass index (BMI).

METHODS

GH response to growth hormone-releasing hormone (GHRH)+arginine (Arg), femoral neck BMD (g/cm2) by dual energy X-ray absorptiometry, BMI, serum-ionized calcium, parathyroid hormone (PTH) and markers of bone remodelling were evaluated in all patients and controls.

RESULTS

Among PHP patients, GH secretion was reduced (8.8 +/- 4.2 microg/l, range 1.1-16.5 microg/l) in 34 patients and normal (28.7 +/- 11.8 microg/l, range 17.9-55.7 microg/l) in the remaining 16 (P < 0.05), no women in the control group had GHD (peak GH 33.8 +/- 10.9 microg/l, range 21.7 +/- 63.2 microg/l). Osteoporosis (T-score < - 2.5) and osteopenia (T-score > -2.5 and < -1) were found in 73.5 and 17.6% of GHD patients, in 37.5 and 43.7% of patients with normal GH secretion and 3.1 and 27% of controls. T-score and BMD were not correlated with ionized calcium, age, age at menopause, BMI, GH peak and IGF-I but were correlated with serum PTH levels in both groups. T-score was correlated with serum levels of markers of bone remodelling only in PHP patients with GHD.

CONCLUSIONS

Concomitant impairment of GH secretion may play a pathogenetic role in the occurrence of changes in bone mass observed in PHP and contribute to make them more severe.

An update on the pharmacological management of hyperthyroidism due to Graves' disease

Pharmacological treatment, usually by thionamides (carbimazole, methimazole, propylthiouracil) is, in addition to radioiodine therapy and thyroidectomy, one of the available therapies for Graves' hyperthyroidism. Thionamides represent the treatment of choice in pregnant women, during lactation, in children and adolescents and in preparation for radioiodine therapy or thyroidectomy. Side effects are relatively frequent but are in general mild and transient. Two main regimens are available: titration method (use of the lowest dose maintaining euthyroidism; duration: 12-18 months) and block-and-replace method. Neither one has clear advantages in terms of outcome but the latter method is associated with more frequent side effects. Hyperthyroidism relapses in approximately 50% of patients, to whom ablative therapy should be offered.

Identification of acromegalic patients at risk of developing colonic adenomas

BACKGROUND

Acromegaly seems to be associated with an increased prevalence of colonic adenomas, although factors affecting their development and recurrence of the latter are not fully known.

SUBJECTS AND METHODS

Seventy-nine patients with active acromegaly were prospectively followed up for 5 yr. Two hundred eighty healthy subjects served as controls. Colonoscopy and assessment of acromegaly activity were performed at 1-yr intervals. Acromegaly was defined as controlled if serum IGF-I levels were within the normal age-adjusted range.

RESULTS

Colonic adenomas were found in 26 of 79 acromegalic patients (32.9%) and 60 of 280 controls (21.4%) at baseline (P = 0.035, adjusted for age and sex, odds ratio 1.82, 95% confidence interval, 1.02-3.25). Seven patients had hyperplastic polyps; the remaining 46 acromegalic patients had no detectable lesions at baseline and did not develop adenomas during the study period. Of the 26 patients with colonic adenomas at baseline, 16 (61.5%) had at least one recurrence of colonic adenomas (P < 0.0001 vs. patients without colonic lesions at baseline), and multiple recurrences were more frequent in patients with uncontrolled acromegaly (66.7% vs. 17.6% in patients with controlled acromegaly, P = 0.028).

CONCLUSIONS

The first colonoscopy helps to identify acromegalic patients at high risk of developing colonic adenomas. If colonic adenomas are not present initially, it is unlikely that they develop thereafter, independently of metabolic control of acromegaly. Conversely, new lesions are frequent (and often multiple) in patients who already have colonic adenomas at baseline, particularly if acromegalic disease is poorly controlled by treatment.

Thyroid hormone and thyrotropin regulate intracellular free calcium concentrations in human polymorphonuclear leukocytes: in vivo and in vitro studies

Intracellular free calcium concentrations (Ca++i) were studied in polymorphonuclear leukocytes (PMNs) from 13 athyreotic patients who had been previously treated by total thyroidectomy and radioiodine therapy for differentiated thyroid carcinoma, and from age- and sex-matched euthyroid healthy controls. Patients were studied twice, when hypothyroid (visit 1) and after restoration of euthyroidism by L-T4 TSH-suppressive therapy (visit 2). PMNs from patients at visit 1 had significantly lower resting (Ca++)i levels compared to both visit 2 and controls. Values at visit 2 did not differ from those of the controls. Stimulus-induced (Ca++)i rise was also significantly blunted at visit 1 and normalized at visit 2, possibly through a differential contribution of distinct intracellular Ca++ stores, as suggested by the response pattern to the chemotactic agent, N-formyl-Met-Leu-Phe (fMLP), to the selective SERCA pump inhibitor, thapsigargine, and to the mitochondrial uncoupler, carbonyl cyanide p-trifluoromethoxyphenyl-hydrazone (FCCP). In vitro treatment of PMNs from healthy subjects with high TSH concentrations impaired intracellular Ca++ store function. Both resting (Ca++)i levels and fMLP-induced (Ca++)i rise increased in the presence either of low-concentration TSH or of T4, but effects of TSH and T4 were not additive. T3, rT3, and TRIAC had no effect. In conclusion, this study provides evidence for a direct relationship between thyroid status and (Ca++)i homeostasis in human PMNs, mainly related to direct actions of TSH and T4 on these cells.

Uptake of amiodarone by thyroidal and non-thyroidal cell lines

Amiodarone perturbs thyroid function, causing overt hypothyroidism or hyperthyroidism in 15% of patients. Changes in thyroid function are likely due, at least in part, to amiodarone and/or desethylamiodarone (DEA) concentration into the thyroid gland, but mechanisms whereby the drug uptake occurred are not known. Thyroidal (FRTL-5) or non-thyroidal [Chinese hamster ovary wild-type (CHOwt) or CHO stably transfected with NIS (CHO-NIS)] cells were exposed to 10 microM amiodarone or DEA. Cellular content of both drugs was measured by HPLC and normalized by protein concentration. Cellular concentration of the two drugs was higher in FRTL-5 (mean +/- SD 17.2 +/- 1.2 microg/mg protein of amiodarone and 18.9 +/- 0.7 microg/mg protein of DEA) than in CHO-NIS and CHOwt cells (10.8 +/- 0.8 microg/mg protein and 12.8 +/- 0.2 microg/mg protein, respectively, of amiodarone (p < 0.004); 11.9 +/- 0.1 microg/mg protein and 11 +/- 0.2 microg/mg protein, respectively, of DEA (p < 0.0002). DEA concentration was higher than that of amiodarone in all cell lines (p < 0.002). Differences between FRTL-5 and CHO cell lines were not dependent on TSH: in fact, cellular content of either drug did not change in the presence or absence of TSH in the culture medium. NIS did not intervene in amiodarone or DEA entry into thyroid cells, since amiodarone and DEA content was the same in CHOwt and CHO-NIS cells; in addition, KClO4 inhibited NIS function, but had no effect on drug uptake by the cells. At variance, 80 microM DEA reduced 125I uptake by CHO-NIS cells by 40% at 30 min without affecting cell viability. In conclusion, mechanisms whereby amiodarone is taken up by thyroid cells remain largely unknown, but the two main factors involved in thyroid-specific cellular transport, ie, NIS and TSH, seem to be excluded.

Apoptosis is reduced in the colonic mucosa of patients with acromegaly

BACKGROUND

Patients with acromegaly have an increased risk of developing colonic tumours; reduced apoptosis is considered a leading mechanism in tumorigenesis. GH and IGF-1 decrease apoptosis in several cell lines including human colonic adenocarcinoma, but it is unknown whether epithelial cells of colonic mucosa of patients with acromegaly have reduced apoptosis.

AIM

The aim of the study was to evaluate the degree of apoptosis in a cross-sectional study, in biopsy samples of colonic mucosa obtained from patients with acromegaly.

PATIENTS AND METHODS

Eleven patients with active, untreated acromegaly (AcroUntr), 16 patients with acromegaly in remission (AcroRem) and 23 controls were enrolled in the study. Samples of colonic mucosa were obtained during colonoscopy; apoptosis was evaluated by either DNA fragmentation or terminal deoxynucleotidyl transferase assay.

RESULTS

Apoptotic cells were 60.0 +/- 2.5% in samples of colonic mucosa of controls, 62.0 +/- 3.4% in those from patients with AcroRem (P = ns vs. controls), and 39.0 +/- 4.1% in those from patients with AcroUntr (P < 0.0001 vs. the other groups). Apoptosis was inversely related to serum IGF-I (r = 0.771, P < 0.001) or GH (r = 0.404, P = 0.05) levels and less to the estimated duration of disease (r = 0.384, P = 0.07). PPARgamma is considered to be a tumour suppressor gene the expression of which might be involved in colonic tumorigenesis. The expression of PPARgamma was lower in the colonic mucosa of patients with AcroUntr (2845 +/- 947 transcripts) than in that of controls (35 200 +/- 2450 transcripts) or AcroRem (29 547 +/- 3650 transcripts) (P < 0.005). The recovery of PPARgamma expression was associated with apoptosis in most cells. The lower degree of apoptosis in patients with AcroUntr was associated with a reduced expression of the antiapoptotic Bax protein.

CONCLUSION

In conclusion, patients with AcroUntr have reduced apoptosis in colonic mucosa that is apparently reversed after acromegaly is cured. It is conceivable that reduced apoptosis may represent an early event in colonic tumorigenesis of patients with acromegaly.

Thyroid hormone regulation of cell migration and oxidative metabolism in polymorphonuclear leukocytes: clinical evidence in thyroidectomized subjects on thyroxine replacement therapy

Migration and superoxide anion (O2-) generation were studied in polymorphonuclear leukocytes (PMNs) from 14 athyreotic patients, previously treated by total thyroidectomy and radioiodine therapy for differentiated thyroid carcinoma, and from age- and sex-matched euthyroid healthy controls. Patients were studied twice: in hypothyroidism (visit 1) and after TSH-suppressive L-T4 replacement therapy (visit 2). Random migration and N-formyl-Met-Leu-Phe (fMLP) 0.1-microM induced chemotaxis were similar in cells from patients at both visit 1 and visit 2 and from healthy controls. On the contrary, resting O2- generation in cells from patients was significantly lower than control values, both at visit 1 and 2. At visit 1, fMLP 0.1 muM-induced O2- generation was significantly lower than control values, while phorbol-myristate acetate (PMA) 100-ng/ml induced O2- generation was similar in cells from patients and from controls. At visit 2 both responses increased, resulting in fMLP-induced O2- generation superimposable to control values and PMA-induced O2- generation significantly higher with respect to both visit 1 and cells from controls. In vitro exposure of PMNs from healthy subjects to L-T4 did not affect O2- generation in resting cells, and significantly increased that induced by fMLP or PMA only at high, supra-physiological concentrations. Neither TSH nor T3 had significant effects at any of the concentrations tested. The present results document the existence of a correlation between thyroid status and oxidative metabolism of human PMNs, which is however unlikely to depend upon a direct action of thyroid hormones on these cells.

Orbital decompression in graves' ophthalmopathy by medial and lateral wall removal

OBJECTIVE

The objective of this study is to describe a technique for balanced orbital decompression and to analyze the results.

METHODS AND MATERIALS

We conducted a retrospective study of 140 patients (276 orbits). Orbital decompression was carried out by removal of the medial orbital wall by ethmoidectomy and complete removal of the lateral wall by bringing out the entire sphenoid wing together with part of the zygomatic bone down to the inferior orbital fissure.

RESULTS

One hundred thirty-six patients underwent bilateral decompression, 4 patients underwent monolateral decompression. Proptosis was reduced on average by 5.3 mm; 28 (20%) patients showed onset or worsening of diplopia.

CONCLUSIONS

Medial and lateral approach allows a balanced orbital decompression. As some patients may present different degrees of proptosis and visual impairment, we stress the importance of carefully weighing the preoperative conditions of the individual patient when choosing the surgical approach.

An update on medical management of Graves' ophthalmopathy

Graves' ophthalmopathy (GO), the most frequent extrathyroidal manifestation of Graves' disease, is a disorder of autoimmune origin, the pathogenic mechanisms of which are still incompletely understood. Although GO is severe in only 3-5% of affected individuals, quality of life is severely impaired even in patients with mild GO. Management of severe GO can be either medical or surgical (orbital decompression, eye muscle or lid surgery). Medical management relies on the use of high-dose systemic glucocorticoids or orbital radiotherapy, either alone or in combination. Studies carried out in the last 5 yr have shown that glucocorticoids are more effective through the i.v. route than through the oral route. However, particular attention should be paid to possible liver toxicity of i.v. glucocorticoids. Recent randomized clinical trials have, with one exception, confirmed that orbital radiotherapy is an effective and safe therapeutic procedure for GO. At variance with previous encouraging data, recent randomized clinical trials have shown that currently available SS analogs are not very effective in the management of GO. Antioxidants might have a role, at least in mild forms of GO. Particular attention should be paid to correction of risk factors (cigarette smoking, thyroid dysfunction, radioiodine therapy) involved in GO progression.

Thyroid function differently affects serum cystatin C and creatinine concentrations

Cystatin C (Cys C) is a cysteine protease inhibitor produced at a constant rate by nucleated cells, filtered through the glomerular membrane and reabsorbed by kidney tubular cells. Aim of this cross-sectional and longitudinal study was to assess serum Cys C and creatinine (Crea) concentrations in thyroid dysfunction. One hundred and eighty-one patients, 26 with untreated non-toxic nodular goiter, 58 with hyperthyroidism, 31 on L-T4 suppressive therapy for non-toxic nodular goiter, 35 with short-term hypothyroidism after L-T4 withdrawal to perform whole body scan for thyroid cancer, 11 with long-term hypothyroidism due to chronic autoimmune thyroiditis and 20 patients with mild hypothyroidism were enrolled in the study. Fifty-seven age- and sex-matched normal subjects served as controls. Serum Cys C, Crea, free T4 (FT4), FT3 and TSH were assessed. Thirty hyperthyroid patients and 35 short-term hypothyroid patients were followed prospectively until euthyroidism was reached by methimazole or L-T4 therapy. The cross-sectional study showed that mean serum Crea concentrations were significantly reduced in overt hyperthyroid or subclinical hyperthyroid patients, while it was increased in overt hypothyroid patients, but not in mild hypothyroidism. Conversely, serum Cys C levels were significantly increased in overt hyperthyroid patients compared to controls (p<0.05), and significantly decreased in short-term, long-term and mild hypothyroids (p<0.05, p<0.05, p<0.01, respectively). However, 36 (62%) hyperthyroid patients and 50 (76%) hypothyroid patients had normal serum Cys C values. In the prospective study, restoration of euthyroidism by either methimazole or L-T4 therapy was associated with normalization of mean serum Cys C concentrations. In conclusion, thyroid dysfunction affects serum Cys C concentration, possibly influencing the production rate of the protein. However, the observation that hyper- or hypothyroid patients have normal serum Cys C levels limits its use as a marker of peripheral thyroid hormone effect.

Autoimmune hepatitis during intravenous glucocorticoid pulse therapy for Graves' ophthalmopathy treated successfully with glucocorticoids themselves

We report a case of acute hepatitis of autoimmune origin which occurred in a 43-yr-old woman during iv glucocorticoid (GC) pulse therapy for Graves' ophthalmopathy (GO). Prior to therapy, liver function tests were normal with no previous history of liver disorders or conditions predisposing to GC-associated liver damage. After the administration of a 4.7-g cumulative dose of methylprednisolone acetate, there was a marked increase of liver enzymes, prompting immediate discontinuation of iv GC. Nevertheless, liver enzymes increased further, reaching a peak 45 days later, with values 30- to 50-fold greater than those prior to therapy, associated with evidence of impaired liver function. Liver biopsy showed a marked lymphocytic infiltration, likely indicating an autoimmune hepatitis. Based on the assumption that following GC-induced immune suppression, autoimmune hepatitis might have been precipitated by sudden re-activation of the immune system during interpulse periods, we treated the patient with im and then oral GC, in order to re-induce immune suppression. Within three days from re-institution of GC therapy, there was a marked reduction of liver enzymes and amelioration of liver function. Complete normalization was achieved two months later, while the patient was still receiving a low maintenance dose of oral prednisone.

Growth hormone secretion in primary and secondary hyperparathyroidism

Primary hyperparathyroidism (PHP) is associated with impaired GH secretion. Whether this effect is due to hypercalcemia or to increased serum PTH concentration is unclear. However, patients with familial hypocalciuric hypercalcemia (FHH), who have normal PTH and increased serum calcium concentrations, also have an impaired GH secretion, suggesting that calcium rather than PTH is responsable for this effect on GH secretion. To further investigate this issue, 10 consecutive patients with secondary hyperparathyroidism (SHP) due to vitamin D deficiency were evaluated by the GH response to GHRH+arginine (Arg) test. A group of 60 consecutive untreated PHP patients served as controls. Mean GH response to GHRH+Arg test was 15.8+/-14 microg/l and 37.5+/-16 microg/l (p<0.001) in PHP and in SHP patients, respectively. Forty-two out of 60 (70%) PHP patients had a suppressed or blunted GH response, whereas all SHP patients had normal GH response. The results of the present study confirm and extend our previous observations that PHP is associated with an impaired GH secretion in the majority of cases, and indicate that SHP patients have no abnormality of GH secretion. Thus, hypercalcemia rather than increased serum PTH is responsible for the abnormality of GH secretion.