Autoimmune thyroid diseases are more common in patients with prolactinomas: a retrospective case-control study in an Italian cohort.

BACKGROUND: Prolactin may exert immunological effects. Over the years, a higher prevalence of autoimmune thyroid diseases (ATD) has been reported in patients with prolactinomas (PRLs) in areas with sufficient iodine intake. PURPOSE: The aim of our study was to evaluate the prevalence of ATD [Graves' disease (GD) and chronic autoimmune thyroiditis (AIT)] in a retrospective cohort of Italian patients with PRLs compared to a sex-matched control group, represented by subjects with non-functioning pituitary adenoma (NFPA) or empty sella (ES). MATERIALS AND METHODS: We enrolled 149 patients (108 F/41 M) with PRLs (110 micro/39 macro) and 143 subjects (100 F/43 M) with NFPA (n = 96, 56 micro/40 macro) or ES (n = 47), with normal serum prolactin. Neck ultrasound and thyroid function tests (anti-thyroid antibodies, TSH, FT3 and FT4) were performed in all patients. RESULTS: In PRLs, median serum prolactin was significantly higher (98.3 vs. 8.9 ng/ml, p ≤ 0.0001), while age was lower (34 vs. 46 years, p ≤ 0.001) compared to controls. The prevalence of ATD was 13.4% (20/149) in PRLs (1 GD and 19 AIT) compared to 6.3% (9/143) in the controls (p = 0.042). At the multivariate analysis, serum prolactin was the only independent factor predicting ATD. Thyroid volume (12.5 ± 5.9 ml vs. 12.8 ± 10 ml, p = 0.47) and the presence of uni- or multinodular goiter (29.5% vs. 35%, p = 0.35) did not differ between PRLs and control groups. CONCLUSIONS: Our data in an area with mild iodine deficiency confirm a higher prevalence of ATD in patients with prolactinomas.

Alterations of the FSH and LH receptor genes and evaluation of sperm ultrastructure in men with idiopathic hypergonadotropic hypogonadism.

PURPOSE: Gonadotropins, interacting with their gonadal receptors, play a key role in sexual development, reproductive functions and metabolism. In this study we performed the genetic analysis of FSHR and LHR and semen investigation in 14 infertile men with normal level of T and elevated levels of FSH and/or LH in the absence of other causes of infertility. METHODS: Sperm parameters were analysed following WHO (2010) guidelines and sperm morphology by Transmission Electron Microscopy (TEM) analysis mathematically elaborated. FSHR and LHR gene mutations have been searched by PCR technique, followed by DHPLC analysis and direct sequencing. RESULTS: In FSHR, we found no difference in the frequency between Ala or Thr at position 307, Ser was at codon 680 in all subjects. Three patients had an heterozygous mutation at codon 419. Three intronic polymorphisms (rs2091787, rs6708637, rs1922464) were significantly found compared to controls; the single allele frequency and the odds ratio were calculated. Two new variants: the Cys338Arg and the Gln123Glu were detected in two different patients. Regarding LHR, three patients were heterozygous for the known variant Glu354Lys and two for Ile374Thr. Intronic polymorphisms were not identified. A new variant, the Val144Ile was found. By the routine semen analysis, variable seminal conditions in this group of patients was observed, on the contrary TEM data mathematically elaborated showed a homogeneous decrease in fertility index and increase in sperm pathologies such as apoptosis and immaturity. CONCLUSIONS: The obtained results suggest that a deeper examination of spermatozoa, achieved by the use of more powerful tools such as TEM or molecular analysis, are advisable in patients with hypergonadotropic hypogonadism.

Effectiveness of radioiodine (131-I) as definitive therapy in patients with autoimmune and non-autoimmune hyperthyroidism.

We evaluated the outcome of radioiodine (RAI) therapy in 100 consecutive patients treated in the period 2000-2001 for hyperthyroidism due to Graves' disease (GD), toxic adenoma (TA) and toxic multinodular goiter (TMG). Thyroid function was measured before and after therapy every 3-6 months up to 3 yr. Three years after therapy, 75% of TA patients were euthyroid, 18.7% were hypothyroid and 6.3% hyperthyroid. Of the TMG patients, 62.2% were euthyroid, 18.9% were hypothyroid and 18.9% hyperthyroid. In GD patients euthyroidism was achieved in 12.9% of the patients, hypothyroidism in 74.2% and hyperthyroidism persisted in 12.9%. Definitive hypothyroidism was significantly higher in GD (p<0.0001) than in TA and TMG patients. Overall, positive effect of RAI (definitive hypothyroidism or euthyroidism) was very high: 93.7% in TA, 81.1% in TMG and 87.1% in GD patients. Thyroid volume reduction was observed in all patients, but was higher in GD patients (mean reduction of 76%) and in TA patients (mean nodule reduction of 69%). In TMG, mean reduction was of 32%. The median activity of RAI received by the 86 cured patients was 555 MBq (15 mCi) compared to 407 Mbq (11 mCi) received by the 14 patients who remained hyperthyroid. No influence was found between outcome and clinical parameters at the moment of 131-I therapy. In conclusion, our results indicate that RAI therapy is highly effective and safe for the control of hyperthyroidism.

Cyclic Cushing's disease with paradoxical response to dexamethasone.

Cyclic Cushing's disease is an unusual disorder characterised by ACTH-dependent periodical increase of serum cortisol levels, clinically accompanied by peripheral edema, abnormalities of cardiac rhythm and hypokalemia. The condition may be unrecognised for years, since the typical features of Cushing's disease are usually absent due to the intermittent and brief duration of cortisol hypersecretion. We describe the case of a 42-yr-old man with Cyclic Cushing's disease due to an ACTH-producing pituitary macroadenoma, who presented two episodes of hypercortisolism in a 3-yr-period, clinically characterised by peripheral edema, hypokalemia and arrhythmia. The diagnosis was suspected because of a paradoxical increase of plasma ACTH and cortisol after dexamethasone administration during an asymptomatic period and was confirmed by pituitary imaging and by final histology after transphenoidal resection of the pituitary adenoma. After surgery, the patient resumed a normal pituitary-adrenal function with restoration of the normal ACTH and cortisol suppression after dexamethasone. Cyclic Cushing's disease should be considered in the differential diagnosis of several conditions characterised by recurrent episodes of idiopathic edema, hypokalemia or unexplained cardiac arrhythmia. In such patients, the pituitary-adrenal axis should be tested possibly during the acute phase of their disease or using the dexamethasone suppression test during asymptomatic intervals.

Multiple endocrine neoplasia type 2 syndromes may be associated with renal malformations.

OBJECTIVE: The RET proto-oncogene is known to be the susceptibility gene for various disease phenotypes, including multiple endocrine neoplasia type 2 (MEN 2). Recent studies have also suggested an involvement of RET in the development of the mammalian kidney. Although kidney agenesis or dysgenesis has been observed in mice lacking functional ret, no clinically relevant kidney abnormalities have been reported in individuals with known RET mutations and familial medullary thyroid carcinoma (FMTC). We have studied a family with five members affected with isolated FMTC. DNA analysis was performed and the involved RET mutation was identified. Amongst these patients were a woman and her son. DESIGN: Case report. SETTING: University department. PATIENTS: A 32-year-old woman and her son with FMTC and unilateral renal agenesis. RESULTS: The woman's abdominal ultrasound findings demonstrated unilateral renal absence of the left kidney. Her son, when only a few months old, had undergone surgical treatment for Hirschsprung's disease. Abdominal ultrasonography was performed recently, and left-side renal absence was diagnosed. Intravenous pyelography confirmed the agenesis of his left kidney, whilst the contralateral kidney displayed compensatory hypertrophy. CONCLUSIONS: The involvement of the RET proto-oncogene in the early growth and differentiation of the human kidney is now generally accepted. We believe that at least a proportion of patients with MEN 2 may have undiagnosed renal malformations. We suggest therefore that noninvasive imaging techniques, such as ultrasonography, should be used to explore the presence of renal abnormalities in subjects with demonstrated RET mutations.

Genetic sperm defects and consanguinity.

BACKGROUND: The existence of a genetic component to human infertility has been suggested, although neither the specific abnormalities involved, nor their genetic mechanism of transmission, are currently defined. We have examined, by transmission electron microscopy (TEM), ejaculate from 1600 males with fertility problems. Among the subjects studied, we focused on a group of patients whose family histories revealed different degrees of consanguinity, in order to evaluate the relationship between consanguinity and particular sperm alterations. METHODS AND RESULTS: A total of 64 consanguineous individuals were identified. In this group, excluding two azoospermic patients, 17 patients (27%) were found to have well recognized genetic ultrastructural defects affecting their entire sperm population: eight subjects had spermatozoa with "stunted tails", four "detached tail" spermatozoa, two "Kartagener's syndrome", two "miniacrosome" and one "round headed" spermatozoa. Since these alterations affect the total sperm population and do not respond to medical treatment, they are suspected of having a genetic origin. The remaining group of 1506 non-consanguineous patients suffered from the same genetic defects in only 15 cases (<1%). CONCLUSIONS: From the data presented, it appears that some very peculiar and rare sperm defects may have a genetic basis since they occur more frequently in consanguineous patients, and are related to different degrees of consanguinity. Since the ejaculate of the remaining patients, both consanguineous and not, showed diverse types of ultrastructural sperm anomalies that did not affect the entire sperm population, they might represent pathologies lacking a genetic basis.

The infection by Helicobacter pylori strains expressing CagA is highly prevalent in women with autoimmune thyroid disorders.

UNLABELLED: H. pylori infection is putatively associated with extra-digestive disorders and may also play a role in the development of autoimmune thyroid diseases (ATD). It was recently found that monoclonal antibodies to an H. pylori strain with cagA-positivity reacted with follicular cells of the thyroid gland, and that an H. pylori organism possessing the cag pathogenicity island carried a gene encoding for an endogenous peroxidase. The aims of this study was (1); To ascertain whether the infection by strains endowed with an increased inflammatory potential (those expressing CagA) could further enhance the risk of developing ATD (2); To verify the possible existence of an immune cross-reactivity between autoantibodies to peroxidase and thyroglobulin and H. pylori antigens (3). To establish whether thyroid colloid antigens could cross-react with an anti-H. pylori serum. The study was partly designed retrospectively. We examined 41 consecutive women with ATD, and, as a control, 33 consecutive age- and socio-economic class-matched women without autoimmune thyroid disorders, living in the same area as patients, occurred at the same institution in the same period (six months). Both patients and controls were examined serologically for H. pylori infection and CagA status by Western blotting. Some serum samples were absorbed with H. pylori to determine whether the antibody levels decreased. Colloid proteins were resolved electrophoretically and matched with a hyperimmune serum raised in rabbits against a CagA-positive H. pylori. Thirty-two patients (78.0%) tested seropositive for H. pylori infection, vs. 16 controls (48.4%) (P = 0.008, OR = 3.78, RR = 1.61). The prevalence of anti-CagA antibodies was 71.8% in infected patients, and 50% in infected controls (P = 0.161, n.s.). The overall prevalence of infection by CagA-positive H. pylori was significantly higher in patients with ATD (23/41, or 56.0%) than that in controls (8/33, or 24.2%) (P = 0.006, OR = 3.99, RR = 2.31). The other tests gave negative or inexplicable results. IN CONCLUSION: CagA-positive H. pylori infection increases the risk of ATD development.

Effects of pravastatin treatment on vitamin D metabolites.

Hyperlipidemias, and notably hypercholesterolemia, represent important risk factors for atherosclerotic vascular disease. The enzymatic inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, a selective and specific key enzyme involved in endogenous cholesterol synthesis, cause a significant mean reduction in low-density lipoprotein (LDL) cholesterol, both in familial and nonfamilial hypercholesterolemic forms. It has been hypothesized that these compounds might interfere with vitamin D endogenous synthesis secondarily to their effects on cholesterol. To verify this hypothesis, we studied 14 hypercholesterolemic patients treated as follows: 4 weeks of low-lipid, fiber-rich diet followed by 8 weeks of pravastatin treatment at the oral evening dose of 20 mg/d and by a 1-month washout period. No significant changes in serum calcium, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D were noticed; on the contrary, significant (P < 0.01) reductions in total cholesterol and LDL cholesterol and a significant (P < 0.05) increase in high-density lipoprotein cholesterol were observed. After the final 1-month washout period, all values returned to baseline levels. In conclusion, our study confirms the clinical efficacy of pravastatin on lipid fractions and demonstrates the absence of any interference on the circulating levels of the main vitamin D metabolites.

Studies on varicocele. II. The inhibin secretion.

In this paper a previous interpretation given by the authors concerning one of the ways varicocele can affect fertility is confirmed. Moreover, it is definitely demonstrated that the high temperature stimulates inhibin secretion (and probably the testosterone-estradiol conversion) in the Sertoli cells, while the somatomedin secretion in vitro seems to be unaffected. It means that the action of the temperature on the germinal cells seems to be mediated by the pathway: inhibin (plus estradiol)-->pituitary-->FSH. Inhibin in the Golgi complex of Sertoli and germinal cells has been detected by electron microscopical immunocytochemical techniques.

Studies on varicocele. 1. Submicroscopical and endocrinological features.

In this study we have selected a group of patients affected by a more or less severe condition of varicocele. After the evaluation of spermatogenesis and sperm function by electron microscopy we have demonstrated that the sperm malformations are mostly due to immaturity. Subsequently we have observed low FSH levels in the blood, concomitant with inhibin high contents, and we have studied Sertoli cells at submicroscopical level. In conclusion we suggest the following mode of action of varicocele in endocrinologically and spermatologically altered patients: varicocele----Sertoli cells----increased inhibin----hypophysis----decreased FSH----decreased testosterone----aberrant spermatogenesis----immature spermatozoa. The research will continue.

Main endocrine modulators of vitamin D hydroxylases in human pathophysiology.

Vitamin D is considered to be devoid of direct biological activity. It must be first hydroxylated in the liver by a 25-hydroxylase (25OHase), then in the kidney by a 1 alpha-hydroxylase (1 alpha OHase) which is responsible for the synthesis of the active metabolite, 1,25-dihydroxyvitamin D (1,25(OH)2D). The activity of 1 alpha OHase is known to be under the control of a series of endocrine modulators, particularly parathyroid hormone (PTH) and estrogens. We report here our studies in humans concerning the behaviour of vitamin D hydroxylases in some pathological conditions. In chronic liver disease no severe impairment of vitamin D-25-hydroxylation has been observed, except in the latest stages: this is probably due to the great functional reserve of the liver, so that normal levels of serum 25OHD can be maintained on condition that the vitamin D supply is adequate. 1 alpha OHase is impaired in chronic renal failure due to the decrease in the number of functioning nephrons. It has been demonstrated that kidney transplantation restores normal 1,25(OH)2D levels. A decrease in 1,25(OH)2D production due to reduced PTH stimulation has been observed in hypoparathyroidism: in these patients a subcutaneous substitution therapy with synthetic human parathyroid hormone resulted in restoration of normal 1,25(OH)2D levels. A reduced activity of 1 alpha OHase due to reduced estrogen stimulation plays a key role in postmenopausal osteoporosis. In these patients estrogens increase 1,25(OH)2D levels, as it has been demonstrated directly and indirectly. In the aforementioned pathological conditions an impairment of calcium absorption has been observed; it was directly related to the reduced production of 1,25(OH)2D. Treatment with 1,25(OH)2D3 was effective in restoring normal calcium absorption. In postmenopausal osteoporosis the reduced levels of 1,25(OH)2D were accompanied by serum levels of 25-hydroxyvitamin D (25OHD) higher than in age-matched control women. In these cases long-term treatment with physiological doses of 1,25(OH)2D3 resulted in a progressive decrease in 25OHD serum levels which approached to the normal range. These findings are likely to be related one to another: the low 1,25(OH)2D levels are responsible for reduced product-inhibition of 25OHase, so that the synthesis of 25OHD increases. A similar mechanism occurs in renal failure and in hypoparathyroidism.

Vitamin D status in the extreme age of life.

The aim of the present study was to investigate vitamin D status in the extreme age of life and to assess the ability of elderly people to synthesize vitamin D in skin, in response to artificial ultraviolet irradiation, and to hydroxylate the newly synthesized vitamin in the liver. The authors have determined the serum 25-hydroxyvitamin D concentrations in 43 healthy subjects (17 males and 26 females) aged 84 years or more. The changes induced in 25-OHD serum levels by whole-body artificial ultraviolet irradiation have also been studied in 10 healthy volunteers aged 41-90 years and, as a control, in 8 normal subjects aged 24-40 years. Serum 25-OHD has been determined, after lipid extraction of samples and column chromatography, by competitive protein binding assay using rat serum as the source of binding protein. The mean 25-OHD serum level in the group studied was 5.7 +/- 4.3 ng/ml, much lower than the mean observed in normal subjects aged 20-40 years (21.3 +/- 8.2 ng/ml). Men had higher levels than women. In the age group 84-89 years 25-OHD levels were higher than in subjects aged 90-96. Serum 25-OHD increased remarkably in all our normal subjects in response to artificial ultraviolet irradiation. Age-related differences in 25-OHD response to irradiation were not significant. The results of the present study indicate that vitamin D deficiency is common in the extreme age of life. It is probably a consequence of poor diet and lack of exposure to sunshine rather than of an impairment of cutaneous synthesis or liver hydroxylation of vitamin D.

Studies on the hydroxylation of vitamin D in man.

The authors have studied some of the factors influencing vitamin D hydroxylases in man, using two indirect experimental approaches. In the first study they have considered the effect of a long-term treatment with 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on the serum levels of 25-hydroxyvitamin D (25-OHD) in postmenopausal osteoporosis, a condition in which high serum levels of 25-OHD and low mean levels of 1,25(OH)2D have been observed. In the second study the effects of the infusion of physiological doses of human parathyroid hormone (PTH) on the serum levels of 1,25(OH)2D and 24,25(OH)2D have been investigated. In the first study a decrease in the circulating levels of 25-OHD was observed during 1,25(OH)2D3 treatment. This could be considered as an indirect evidence of an inhibitory action of 1,25(OH)2D3 on 25-hydroxylase: in this view 1,25(OH)2D3 treatment decreases 25-hydroxylase activity, which is higher than normal in postmenopausal osteoporosis due to the low levels of 1,25(OH)2D. In the second study PTH infusion was followed by a remarkable increase in 1,25(OH)2D serum levels as a result of 1 alpha-hydroxylase stimulation, which was much higher in patients with hypoparathyroidism. The determination of 24,25(OH)2D levels during PTH infusion indicated an inhibitory effect on 24-hydroxylase.

[A rapid method for assay of 25-hydroxyvitamin D in serum]. / Metodo rapido per il dosaggio della 25-idrossivitamina D nel siero.

A simplified assay for 25-hydroxyvitamin D is reported. In this procedure ethanol extraction is used in order to obtain a better protein precipitation and a higher recovery of added tritiated 25-hydroxyvitamin D3. Extraction is followed by column chromatography on Sep-pak Silica cartridges. The eluate is dried and directly used for competitive protein binding assay. The method shows two main advantages: it is less time consuming and is easier to perform than existing procedures.

[Assay of 24,25-dihydroxyvitamin D by competitive protein binding]. / Dosaggio della 24,25-diidrossivitamina D per competizione di legame proteico.

A competitive protein binding radioassay for 24,25-dihydroxyvitamin D in human serum has been developed, which is relatively simple and rapid. Acetonitrile is used for sample extraction and protein precipitation. column chromatography is then performed in a Sep-pak cartridge. High pressure liquid chromatography follows. The dried eluate is assayed using rat serum as the source of binding protein. Since 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 are equipotent in their competitive displacement of tritiated 25-hydroxyvitamin D3 from at serum, 25-hydroxyvitamin D3 can be used as the assay standard.

Effect of the administration of 1,25-dihydroxyvitamin D3 on serum levels of 25-hydroxyvitamin D in postmenopausal osteoporosis.

Serum concentrations of 25-hydroxyvitamin D were measured in a group of women with symptomatic postmenopausal osteoporosis, before and after long-term treatment with physiological doses of 1,25-dihydroxyvitamin D3. A competitive protein binding assay was used, which included a chromatographic step. The treatment resulted in a significant decrease in serum 25-hydroxyvitamin D levels that were higher than normal in basal conditions, the mean values before and after therapy being 27.7 ng/ml (+/- 17.1 SD) and 19.7 ng/ml (+/- 12.7), respectively. These findings seem to confirm the hypothesis that an inadequate product-inhibition of liver 25-hydroxylase is responsible for the increased basal levels of 25-hydroxyvitamin D found in postmenopausal osteoporosis.

[Seasonal rhythm in 25-hydroxyvitamin D blood levels]. / Dei livelli di 25-idrossivitamina D nel siero.

A retrospective study of the serum concentrations of 25-hydroxyvitamin D was performed over a one-year period, using data from 158 healthy subjects aged 40-80 years. Serum 25-hydroxyvitamin D was determined by competitive protein binding assay; the method included a chromatographic step. A noticeable seasonal variation was observed, with a maximum in summer.