AB1189 THE RISK OF FLARE UP FOLLOWING nSARS-CoV2 VACCINE IN INFLAMMATORY ARTHRITIS

Background

As autoimmune phenomena following anti-nSARS-CoV2 vaccine was reported in the healthy population, there is increasing concern in patients with inflammatory joint diseases regarding possible side effects and disease flare-ups.

Objectives

We set out to evaluate the possible risk of disease exacerbation and the predisposing risk factors for the flare up.

Methods

This is a single center prospective cohort study, enrolling patients attending Arthritis Clinic at San Bortolo Hospital, during a follow-up of 12 months. All patients, after obtaining informed consent, answered a 24-item questionnaire including information about nSARS-CoV2 infection, vaccination, disease activity, ongoing treatment, vaccine side effects, disease flare up and need to change therapy.

Results

A total of 109 patients, 60 (55.1%) females and 49 (44.9%) males with a mean age of 60.1 years ±12.6 SD were enrolled. Forty-three (39.5%) were affected by rheumatoid arthritis, 43 (39.5%) from psoriatic arthritis and 23 from anchylosing spondylitis. There were 19 (17.43%) nSARS-CoV2 infection, of them 3 (15.8%) need hospitalization. Ninety-five (87.2%) receive at least one shot of nSARS-CoV2 vaccine, of these 78 (82.1%) got three shots of vaccine. Vaccine-related side effects were reported in 36 (37.9%), of these 15 (41.7%) have fever, 14 (38.8%) arthralgia and 29 (80.5%) fatigue. No patients required medical attention. Twenty (21.05%) of patients who receive at least one vaccine shot experienced a flare up. Nine (45%) need to change therapy. The risk of flare up was significantly associated with low disease activity/active disease in the last 12 months, p=0.009; OD 4.0; 95% CI: 1.5-11.3.

Conclusion

Overall, the nSARS-CoV2 vaccine is well tolerated in patients with inflammatory arthritis. The risk of disease flare is associated with active disease within the past 12 months. According to our results, the patients affected by inflammatory arthritis in sustained remission have no reason to hesitate to get the nSARS-CoV2 vaccination.

Disclosure of Interests

None declared

AB1153 HYPEREOSINOPHILIC SYNDROME FOLLOWING THE BNT162b2 (BioNTech / PFIZER) VACCINATION

Background

Some reports of small vessel vasculitis following nSARS-CoV2 vaccination are reported in the literature (1, 2).

Objectives

We purpose to report the case of small-medium vessel vasculitis after BNT162b2 (BioNTech/Pfizer) vaccination.

Methods

We present the case of a 48 years old man with an unremarkable history who underwent BNT162b2 vaccination.

Results

Five days after the first shot of BNT162b2 vaccine, the patient refer the onset of left inguinal adenopathy, and erythematous dermatitis of the trunk. Ultrasound of the groin found increase bilateral inguinal lymph nodes with reactive characters. Contextually, erythematous, itchy and painful nodular lesions appear in the lower and upper limbs as well as acrocyanosis and paresthesia in the right hand and foot. The tests performed showed thrombocytopenia and eosinophilia. While, CRP, search for fecal parasites, pANCA, cANCA, ANA, RAST test, serum tryptase were all absent. Haematological evaluation, bone marrow biopsy, karyotype and molecular biology (FIP1L1/PDGFRa), were performed, all results negative. The patient was admitted in Internal Medicine ward for worsening of skin lesions and of acrocyanosis with gangrenous lesions at the tips of the fourth finger of the right hand. An angio-CT showed an occlusion of the right ulnar artery. At electromyography an axonal sensory neuropathy was found. The skin biopsy showed fibrinoid necrosis of venules of the superficial vascular plexus associated with numerous eosinophils, lymphocytes and karyorrhetic debris (Figure 1). High-resolution CT scan described diffuse minimal accentuation of the interstitial texture with micronodular aspects and some ground glass appearance. The diagnosis of hypereosinophilic syndrome was made. Therapy with Methylprednisolone 500 mg/daily for 3 days then Prednisone 1 mg/ kg daily in association with IL-5 inhibitor (mepolizumab) with good clinical response, in addition to anticoagulation with warfarin was started.

Figure 1.

Conclusion

To our knowledge this might be the first case of (HES) following COVID vaccine. As our experience, due to the short commercialization of anti-nSARs-CoV2 vaccines, is limited further studies are needed to explore the possible effect on small-medium vessels.

References

[1]Shakoor MT, Birkenbach MP, Lynch M. ANCA-Associated Vasculitis FollowingPfizer-BioNTech COVID-19 Vaccine. Am J Kidney Dis. 2021 Oct;78(4):611-613. doi:10.1053/j.ajkd.2021.06.016.

[2]Altun E, Kuzucular E. Leukocytoclastic vasculitis after COVID-19 vaccination.Dermatol Ther. 2021 Dec 20:e15279. doi: 10.1111/dth.15279.

Disclosure of Interests

None declared

AB0143 THE EFFECT OF RHEUMATOID ARTHRITIS AND SPONDILOARTHRITIS ON PREGNANCY: A LONGITUDINAL RETROSPECTIVE COHORT STUDY

Background:

Many patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) are in their childbearing years. Concerns exist regarding the interplay between the rheumatic diseases and the pregnancy (1).

Objectives:

Actually, there are contradictory data regarding the pregnancy outcome in patients with RA and SpA (2). Thus, we performed this longitudinal retrospective study to evaluate the effect of RA and SpA on pregnancy outcome.

Methods:

The data of 78 pregnancies of 60 women followed from April 2017 to December 2020 at pregnancy clinic of Internal Medicine Unit, San Bortolo Hospital, Vicenza and Rheumatology Unit, University of Verona were reviewed. Fifty (64.1%) women were affected by RA and 28 (35.9%) by SpA. Information regarding demographic data, disease activity, drug exposure and maternal/foetal outcomes were collected in an electronic database. Details concerning pregnancy complications and congenital malformation were also collected. We compared pregnancy and foetal/neonatal outcome, medication use and disease activity between women affected by RA and SpA. Moreover, we evaluated the effect of disease activity on pregnancy outcome.

Results:

Overall, there were 70 (86.4%) live births, 10 (12.3%) miscarriages and 1 (1.2%) foetal death. There were three twin pregnancies. Even there was a higher rate of glucocorticoids and bDMARDs use in RA than in SpA group, respectively 40% vs 21% and 70% vs 57,1%, there were no statistical differences regarding drug exposure at conception. Moreover, there were no differences concerning disease activity at conception. Still, a higher rate of glucocorticoids and bDMARDs, respectively 26% vs 10.7% and 46% vs 39.3% were used in RA than in SpA patients during pregnancy. Furthermore, we did not find any statistical differences regarding maternal and foetal/neonatal outcome between pregnancies in the RA and those in the SpA groups. There were four (4.9%), congenital malformation, two (3.8%) in RA group and two (6.9%) in SpA group. About one-third of patients 24 (30.7%) presented a moderate disease activity at conception as evaluated by DAS28PCR and BASDAI. However, there were no significant differences, on maternal and foetal/neonatal outcome in patients with moderate activity disease with respect of those in clinical remission.

Conclusion:

Even a higher rate of glucocorticoids and bDMARDs were used in RA than in SpA patients, there was no differences on pregnancy outcome between them.

References:

[1]Ostensen M. Nat Rev Rheumatol. 2017;13:485-493. doi: 10.1038/nrrheum.2017.102.

[2]Polachek et al. J Rheumatol 2020;47:161-163. doi: 10.3899/jrheum.190631.

Disclosure of Interests:

None declared

131I therapy for hyperthyroidism and consequent appearing of anaplastic carcinoma of the thyroid: simple case-report or real pathophysiologic link?

BACKGROUND 131I is usually employed for the therapy of hyperfunctioning thyroid diseases. This β-emitting radioisotope acts releasing its radiations in small tissue volumes, but it is mandatory to consider, also for the small doses, the carcinogenic risk, well documented with the high 131I dosages used to cure differentiated thyroid cancers. METHODS We describe a case of anaplastic thyroid carcinoma appeared 4 years after therapy with 131I for Graves’ disease. The patient was treated both surgically and with thyonamides for Graves’ disease 20 years before; thereafter she underwent simple nephrectomy owing to Grawitz disease. After some years of well being, she was treated with 131I for a relapse of Graves’ disease. Four years later, she was treated with interleukin-2 and TNF-α, owing to distant metastases (pancreas, liver and lung) of Grawitz cancer. Some months later, because of a rapid enlargement of the thyroid gland, she was thyroidectomized and anaplastic thyroid cancer was histologically documented. DISCUSSION AND CONCLUSIONS It is very difficult to investigate the possible transformation of a benign thyroid lesion to a malignant one, and data from the literature are conflicting. Fractioned doses of 131I are known to induce less cancers than high doses: they allow DNA to repair. Nevertheless, in patients with altered or non valid genetic repair’s mechanisms (i.e. patients with p53 mutations) and, for this reason, prone to develop cancers, even low doses of 131I can induce carcinogenetic effects. In a patient with a history of cancer, who subsequently develops hyperthyroidism, even low doses of 131I can induce anaplastic thyroid cancer; in these subjects, therefore, other treatments than 131I could be preferred for the therapy of Graves’ disease. In our peculiar case, moreover, some studies have noteworthy demonstrated that certain cytokines (IL-1, TGF-β1 e TNF-α) can, rather than inhibit, induce anaplastic thyroid cancer cells to grow.

Diabetes, cardiovascular risk factors and idiopathic sudden sensorineural hearing loss: a case-control study

AIMS/HYPOTHESIS

Idiopathic sudden sensorineural hearing loss (ISSNHL) represents an acute inner ear disorder with an overall incidence of 5-20/100000 individuals per year in western countries. No clear causes for this disease have been found so far, but cochlear ischemia has been hypothesized as one of the etiopathological mechanisms. The aim of our study was to assess the role of diabetes and traditional cardiovascular risk factors in the pathogenesis of ISSNHL.

MATERIALS/METHODS

Case-control study of 141 patients (75 males/66 females) matched for age and gender. Cases were affected by ISSNHL, defined as a sudden hearing loss > or =30 dB, within 3 frequencies, developing over 72 h. The control group was composed of 271 sex- and age-matched subjects (142 males/129 females) who agreed to participate in this observational study and provided blood samples for laboratory investigations. Cardiovascular risk factors examined were: diabetes mellitus, smoking history, hypercholesterolemia, hypertriglyceridemia and hypertension.

RESULTS

On the univariate analysis, diabetes prevalence was higher in the ISSNHL group (15.6%) compared to controls (8.5%) (p = 0.03). Also hypercholesterolemia was significantly more frequent in the ISSNHL group compared to the control population. There were no statistically significant differences between the 2 populations concerning other cardiovascular risk factors. The risk of ISSNHL tended to increase as the number of cardiovascular risk factors increased (p for linear trend = 0.018).

CONCLUSIONS

Our findings suggest that diabetes mellitus, hypercholesterolemia and a high burden of cardiovascular risk factors are associated with the risk of ISSNHL.

Parathyroid function study in patients submitted to laryngeal surgery for squamous cell carcinoma

Aim of this study was to investigate any eventual quantitative variations in the serological concentration of parathormone in a homogenous sample of patients suffering from laryngeal squamous cell carcinoma who underwent only surgery. A total of 12 patients (2 female, 10 male), aged between 58 and 76 years, were treated between June 2002 and June 2003. The patients were all affected by T2-T3 laryngeal squamous cell carcinoma. Serum intact parathyroid hormone and calcaemia were measured pre- and post-operatively. Of these patients, 2 underwent total laryngectomy (including thyroid isthmectomy), 5 patients received partial supraglottic laryngectomy, while the remaining 5 were submitted to supracricoid laryngectomy. Results showed a progressive regression of parathyroid hormone level, in only one case and was not, however, below normal limits. Contrary to data reported in the literature, this study indicated that the incidence of hypoparathyroidism following laryngeal surgery, even in radical surgical approaches, proved to be closer to zero.

Difficult hospital discharges in internal medicine wards

OBJECTIVE

Investigate the prevalence of difficult hospital discharges (DHD), describe clinical and social patients' characteristics as potential reasons for discharge delays in an internal medicine ward and implement tailored post-discharge care.

METHODS

During the year 2005 we analysed, in a middle-sized country hospital, all the patients for which some delay for discharge, owing to their whole complexity, was presumable. Comprehensive multidimensional assessment, clinical-social risk score, specific needs of care, mean of stay and outcomes were evaluated.

RESULTS

68.5% of DHD patients were >/=80 years old, with 3.8 the mean number of diseases per patient; 57.5% presented a loss of autonomy (ADL) just before acute deterioration; 80% were functionally and/or cognitively impaired. Only 5% had suitable family support; 5.1% were living at a nursing home; 2% were living alone. The most frequent causes of admission were stroke, cognitive impairment-dementia, cardiovascular diseases, fractures and cancer. Mean length of stay was 12 days. Fifty-two percent of patients were discharged home, 30% were admitted to a long-term care facility, 1% to hospice and 17% died during their hospital stay.

CONCLUSIONS

The aim of "coordinated care" (i.e., targeting "at-risk" patients with assessment of medical, functional, social and emotional needs; provision of optimal medical treatment, self-care education, integrated services, monitoring of progress and early signs of problems) is to improve health outcomes and reduce costs. More than 80% of DHDs patients, with specific tailored programmes, may be discharged from hospital, with satisfactory solutions for them and their families.

Thyroid Function Studies in Patients with Cancer of the Larynx: Preliminary Evaluation

OBJECTIVE: Our goal was to evaluate thyroid function before and after surgery only or radiotherapy plus surgery for laryngeal neoplasms.

STUDY DESIGN AND SETTING: The study group consisted of a total of 30 patients with laryngeal cancer (22 treated with surgery only and 8 treated with surgery plus radiotherapy) who were evaluated by ultrasensitive thyroid-stimulating hormone, free T4, and antithyroid antibodies both preoperatively and at 6 and 12 months after surgery.

RESULTS: All patients had normal thyroid function before treatment (1 patient had elevated antithyroid autoantibodies); after 1 year, 4 (13.34%) patients were hypothyroid. In 3 patients, it was sub-clinical (ie, elevated thyroid-stimulating hormone with normal free T4), and in 1 patient, it was symptomatic.

CONCLUSION: Our preliminary data suggest that hypothyroidism occurs in a small but substantial proportion of patients undergoing surgery with or without adjuvant radiotherapy for laryngeal cancer.

SIGNIFICANCE: Thyroid hormone dosing should be routinely included in the assessment of patients with laryngeal cancer, because it is simple and inexpensive and may allow the early diagnosis and management of hypothyroidism. (Otolaryngol Head Neck Surg 2003;129:733-8.)

[Hemoptysis in a patient with post-obstructive pneumonia due to a broncholith]

A case of a 51-year-old man admitted to the hospital for hemoptysis after a three-week history of fever and cough is presented. The chest x-ray film revealed consolidation in the left upper lobe. Because microbiologic studies of the bronchial lavage showed the grew of Pseudomonas aeruginosa, the patient was treated with piperacilline and pefloxacin. Haemoptysis and abnormal temperature was persistent for several days. Revaluation of the chest x-ray permitted to discover a little calcified nodule of 1 mm diameter. CT scan of the thorax confirmed the consolidation of the left upper lobe and the little calcification. A second fiberoptic bronchoscopy was performed in 10th day, using a bronchoscope with a smaller diameter; it was possible to observe the occlusion of the subsegment bronchus LB 1&2 due to a mobile protruding mass. The mass was gentle removed by the use of alligator bioptic forceps; it presented as a grey, hard, 2 mm diameter body with irregular surface like a "floating mine". On microscopical examination of the mass, aspergillus hyphae appeared as broad septate filaments. Culture of the samples were negative. Haemoptysis and fever stopped after FOB. Chest x-ray in 19th day was negative: consolidation and calcification were absent.

[Atypical presentation of lateral cervical metastasis of occult tumor]

The authors describe the case of a 58 years old man, affected by severe obesity, alcohol addict, observed because of a retromandibular mass, measuring 6 cm. Clinical and instrumental findings indicated the presence of a mass apparently due to a parotid abscess; no evident lesions appeared at the examination of the ENT regions. Ultrasonography and fine needle aspiration cytology revealed the presence of a cystic cervical metastasis of a squamous cell carcinoma arising from an occult tonsillar cancer. The authors describe diagnostic procedures, differential diagnosis, treatment and peculiar aspects related to staging and follow-up.

[Tuberculous otitis]

Recent works show an increase of the incidence of extrapulmonary tuberculosis with a peculiar localization to the middle ear, until now considered a rare clinical manifestation. At the Ear, Noise, Throat Clinic of the University of Ferrara a total of 5 cases of tuberculous otitis media were observed during the last 25 years. Aim of the present study is to describe their clinical manifestations, their symptomatic aspects and the way to reach a careful diagnosis and more rapid therapeutic choice.

Increased risk of autoimmune hypothyroidism in patients affected by retinitis pigmentosa

Patients with Retinitis Pigmentosa (RP) show hemeralopia, restricted field of vision and reduced visual acuity, owing to the degeneration and proliferation of photoreceptors and a retinal pigment epithelium. The prevalence in Italy is 1:4,000. A certain number of "syndromic" associations have been described, and, in particular, also that with hypothyroidism, but very few cases have been studied. We describe a family of 40 people, spanning four generations, in which we have recorded the presence of autosomic dominant RP, associated with autoimmune hypothyroidism or with circulating antithyroid autoantibodies (ATA), currently considered as the expression of active autoimmune thyroiditis or a risk factor for this complaint. We measured, in all members, TSH, FT3, FT4, antithyroglobulin and antithyroperoxidase autoantibodies. A fundus oculi examination was performed in every subject, as well as a careful examine of the anterior region on the neck. A control population of 100 healthy people was also studied. Our data show a higher prevalence of ATA, statistically significant, in the patients with RP and in their relatives, compared with the control population and the data from the literature (13 cases over 40 = 32.5%; p < 0.01). 3 patients with RP and ATA were affected by clinically evident hypothyroidism. 10 patients with ATA were clinically euthyroid; 8 patients affected by RP did not show circulating ATA at the time of the study. The interest for the physician in this "syndromic" retinal distrophy reflects the need, emerging from our data, to test the thyroid function in the subjects with RP and in members of their families, since circulating ATA are considered a risk factor for the development of autoimmune hypothyroidism.

[Community-acquired bronchopneumonias in the elderly. The cost-benefit ratio in some plans of antibiotic therapy]

Community-acquired pneumonias represent the first cause of mortality due to a infectious disease, and determine more than 500,000 hospitalizations per year in the USA: moreover, they are the terminal event in many geriatric patients. Although the etiological microbial agents responsible for the majority of such pneumonias, Haemophilus influenzae and Streptococcus pneumoniae, are still sensitive to traditional antibiotics, as ampicillin, many doctors treat community acquired pneumonias with more recent and expensive antibiotics, as the third generation cephalosporins or other beta-lactamines, so enhancing the cost of the treatments, without a known, real advantage with respect to the older therapies. In this study, to evaluate whether the use of the latter antibiotics improves the outcome of community acquired pneumonias of the elderly with respect to the traditional therapy with ampicillin, we studied 123 hospitalized patients older than 65 years, affected by community-acquired pneumonia, simple or complicated. We also evaluated the cost/benefit ratio of every single treatment. Our data demonstrate that the recent antibiotics do not influence the outcome of the disease of the elderly: in particular, they do not affect the duration of the hospitalization, do not have a lower incidence of side effects, do not show a better efficacy versus ampicillin. The cost of the treatment with ampicillin is about one third of the cost of a third-generation cephalosporin treatment. We conclude that the treatment of choice for community acquired pneumonias of the elderly is ampicillin; only in few cases, as in nosocomial or in nursing homes pneumonias, third-generation cephalosporins or other antibiotics are necessary.

Reduced calcitonin reserve in young hypogonadic osteoporotic men

Calcitonin is a potent inhibitor of bone resorption and in both sexes, plasma levels progressively decrease with age: therefore, a relative deficiency of calcitonin may be involved in the pathogenesis of osteoporosis in the elderly. Calcitonin plasma levels of young hypogonadic men with osteoporosis are significantly lower than controls: the hypothesis that the decreased calcitonin plasma levels in the elderly are due to a reduced secretory capacity of the "C" cells of the thyroid gland, related to age, does not explain the low calcitonin plasma levels found in young hypogonadic osteoporotic men. Our hypothesis is that gonadal steroid deficiency may participate in the mechanisms regulating calcitonin secretion. Therefore, we studied ten males affected by hypogonadotropic hypogonadism and ten normal men, of comparable age, as controls: we measured plasma levels of testosterone, 17 beta estradiol, androstenedione and calcitonin, and the response of calcitonin to an i.v. bolus of pentagastrin, a well known "C" cells stimulatory drug. Testosterone and calcitonin plasma levels and the response of calcitonin to pentagastrin were also evaluated after 6 months of replacement therapy with testosterone. Basal levels of testosterone, 17 beta estradiol, androstenedione and calcitonin, and the response of calcitonin to pentagastrin, are significantly lower in our patients than in controls, demonstrating that hypogonadotropic hypogonadic subjects have a lower secretory reserve of calcitonin. After testosterone therapy the basal calcitonin plasma levels and its response to pentagastrin stimulus did not differ from controls, suggesting that gonadal steroids influence the calcitonin secretion and reserve. Our data cannot clarify whether osteoporosis of hypogonadotropic hypogonadic patients is related to androgen or estrogen deficiency; however, they suggest that the mechanisms by which gonadal steroid influence bone metabolism may involve calcitonin secretion.

Evidence of sperm nuclear chromatin heterogeneity in ex-cryptorchid subjects

Ex-cryptorchid subjects are frequently affected by infertility, even if the usually determined seminal parameters are still within the normal range. We evaluated in this study, in 14 ex-unilateral cryptorchid adult males (22-28 years), with normal sperm concentration, morphology and viability, the resistance of sperm nuclear chromatin to denaturation, using the fluorochrome acridine orange, which fluorescences green when bound to native DNA (double stranded) and red when bound to denaturated DNA (single stranded). Our findings demonstrate that the percentage of green-stained cells with acridine orange was significantly lower in our patients than in controls (p less than 0.001). We therefore suggest that the chromatin of ex-cryptorchid subjects' spermatozoa has a decreased resistance to denaturation and we hypothesize that this finding may explain the infertility of these patients, when the common seminal parameters are still within the normal range.

Testosterone and calcitonin plasma levels in hypogonadal osteoporotic young men

The aim of this study was to ascertain whether there was an interrelationship between male osteoporosis, calcitonin and androgens. Ten young hypogonadal osteoporotic men were studied: testosterone and calcitonin plasma levels were measured before and after therapy with testosterone enanthate (200 mg im every three weeks for four months). In these patients testosterone and calcitonin plasma levels were significantly lower than controls, before therapy (p less than 0.001 and p less than 0.01 respectively). Testosterone treatment significantly increased (p less than 0.05) serum calcitonin. The conclusion was that androgen deficiency may cause osteoporosis also by decreasing calcitonin secretion.

Gonadal steroids deficiency and prolactin response to a met-enkephalin analog in man

The aim of this study was to ascertain whether there is a correlation between gonadal steroids and opioid control of prolactin (PRL) secretion. Four castrated men, aged 18 to 24 years were submitted to intravenous injection of 250 ug of a met-enkephalin analog (D-Ala2-Mephe4-Met-(o)-ol-Enkephalin, FK 33824) (DAMME). In normal men DAMME injection was also performed on the 6th day after treatment with clomiphene citrate (CC) (200 mg/day for 5 days), a specific nonsteroidal estrogen receptor blocker. In castrated men and in normal men after CC treatment, there was a lower PRL response to DAMME than in controls (P less than 0.0005). These results suggest that gonadal steroid deficiency seems to cause a change in the opioid system and/or dopaminergic control of prolactin secretion.

Naloxone reduces the fenfluramine-induced prolactin release in man

In order to ascertain whether there is a relation between opioids and the serotoninergic system in prolactin (PRL) secretion increase, we investigated in seven healthy men (21 to 26 years of age) the effect of naloxone, a specific opioid antagonist, on PRL secretion induced by fenfluramine, a drug that stimulates serotonin release and inhibits its re-uptake. We observed that subjects receiving fenfluramine (60 mg orally) had a significantly (P less than 0.001) higher increase in PRL plasma levels than the controls receiving placebo. In all subjects naloxone infusion at a dose of 15 mg caused a significant reduction (P less than 0.0005) in the PRL response to fenfluramine. Higher doses of naloxone (30 mg) do not further inhibit the PRL secretion induced by fenfluramine. These results suggest that naloxone may interact with opiate receptors on serotonin neurons thereby reducing the synthesis and release of serotonin. It seems that in man, therefore, there is an interplay between opiates and the serotoninergic system in the facilitatory influence on PRL release.

Serotonin but not dopamine is involved in the naloxone-induced luteinizing hormone release in man

Endogenous opioid peptides exert a tonic inhibition on gonadotropin secretion at the hypothalamic level, but the mechanisms by which they act are still unknown. Previous experimental studies suggest that the endogenous opioid peptides change dopaminergic and serotoninergic tones at the hypothalamic level. We have investigated whether the stimulatory effect of naloxone on luteinizing hormone (LH) secretion is due to its influence on these neurotransmitters. Two experimental models were studied, and two sets of effects on LH secretion induced by intravenous naloxone infusion (20 mg over 2 hours) in 14 normal men 20 to 25 years of age were evaluated: the effect of oral sulpiride (150 mg), a potent dopaminergic antagonist, and the effect of oral fenfluramine (60 mg), a drug that stimulates the serotoninergic receptors by releasing serotonin and inhibiting its reuptake. The study demonstrated that naloxone infusion significantly stimulated the LH secretion throughout the period of observation (P less than 0.01 versus saline). The pretreatment with sulpiride did not change the LH response to naloxone. After fenfluramine pretreatment, naloxone failed to induce any rise in LH secretion. Follicle-stimulating hormone did not show any important variation in either test. The data suggest that in man the stimulatory ability of the opiate receptor antagonist naloxone to elicit a rise in LH plasma levels may involve the serotoninergic, but not the dopaminergic, hypothalamic system. This hypothesis, however, does not exclude the involvement of other hypothalamic neurotransmitters.

The influence of gonadal steroids on the dopamine inhibitory effect on gonadotropin release in men

The aim of this study was to ascertain whether an interrelationship exists between gonadal steroids and the inhibition of gonadotropin secretion by dopamine. The effect of dopamine infusion (4 micrograms/kg/minute intravenously) on gonadotropin plasma levels in four castrated men (18 to 23 years of age) and in four age-matched normal men was studied. Normal subjects were studied before and after treatment with a specific nonsteroidal estrogen receptor antagonist, CC. LH plasma levels in normal subjects receiving CC had a maximum decrease percentage and a net decrease significantly greater (P less than 0.005 and P less than 0.012, respectively) than those before CC treatment. In castrated subjects the maximum decrease percentage was significantly greater (P less than 0.005) than in control subjects, but it did not show any difference from that of normal subjects receiving CC. In none of the group were significant changes in FSH concentration observed. The findings suggest that whenever there is a gonadal steroid deficiency, dopamine infusion causes an increased sensitivity to LH inhibition. This may be due to a lower endogenous dopaminergic influence on LH secretion.

Naloxone fails to increase LH levels in clomiphene treated men

The gonadotrophin response to the opiate antagonist naloxone administered per infusion has been investigated before and after 5 days of clomiphene treatment in 5 male subjects. Before clomiphene treatment, naloxone caused a significant increase in LH levels, however, after clomiphene, naloxone failed to induce the same effect. An important role for gonadal steroids on the opiatergic inhibitory tone of LH secretion in man is suggested.

Gonadal steroids and opioid control of gonadotropin secretion in man

The aim of this study was to ascertain whether there was an interrelationship between gonadal steroids and endogenous opioid peptides. The effects of naloxone (20 mg, intravenously) and of a met-enkephalin analog (DAMME) (250 micrograms, intravenously) on gonadotropin secretion in three castrated men (18 to 23 years of age) and in five age-matched normal men were studied. Normal subjects were studied before and after treatment with a specific nonsteroidal estrogen receptor antagonist, clomiphene. Naloxone caused a significant increase in luteinizing hormone (LH) (P less than 0.05); in these subjects, clomiphene treatment significantly increased LH and follicle-stimulating hormone plasma levels but totally suppressed the naloxone-induced rise in LH. In castrated men, naloxone failed to increase plasma LH levels. However, DAMME significantly reduced plasma LH levels in normal, in castrated, and in clomiphene-treated normal subjects. The results demonstrate that in castrated subjects who lack gonadal steroids and in normal subjects with blocked estrogen receptors there is a reduced opioid inhibitory tone on gonadotropin secretion. The effect of DAMME on gonadotropin secretion, however, is not influenced by the gonadal steroid environment.