P-698 Pituitary functioning gonadotroph adenomas (FGA)-induced ovarian hyperstimulation syndrome (OHSS): results from tertiary neuroendocrine centres in the UK

Study question

There are no published series of OHSS due to FGA. What FGA features should clinicians look for during OHSS, and what treatments are effective?

Summary answer

FGA tumour size is always >10mm. Other pituitary hormones may be deficient. Surgical resection of FGA is an effective treatment for OHSS.

What is known already

Pituitary adenomas affect 1:1000 adults and are classified as functioning or non-functioning. Non-functioning pituitary adenomas do not secrete hormones, but most commonly stain histologically gonadotroph cells. Functional pituitary adenomas secrete hormones such as prolactin causing prolactinoma. However, it is rare for a pituitary tumour to cause clinical features of excessive gonadotrophins (functioning gonadotroph adenoma; FGA).

Single case reports, but no case series, have been published on the presentation of FGA-induced OHSS in women.

Surgical excision of adenomas has been reported to cause remission of symptoms, though systematic data are lacking owing to rarity of these tumours.

Study design, size, duration

National case series from tertiary neuroendocrine units in England, Wales and Scotland.

Participants/materials, setting, methods

Eight high-volume pituitary endocrine tertiary units within England, Wales and Scotland audited their records for any cases of FGA-induced OHSS; only seven patients have been identified to date. In all cases, there had been no recent exposure to assisted reproductive technologies (ART) or drugs known to induce OHSS including gonadotrophins or selective oestrogen receptor modulators (SERMS).

Main results and the role of chance

Seven cases of FGA were identified with mean age 31.6 years (range 16-48) at diagnosis. Two-of-seven women presented acutely unwell with abdominal pain, distention and palpable mass requiring oophorectomy for ovarian torsion/ruptured ovarian cyst. The remaining five women presented with abdominal pain (n = 2), thyrotoxicosis (n = 1), menstrual irregularities/galactorrhoea (n = 1) and visual disturbances (n = 1). All women experienced intermittent pelvic pain during medical attendance. Pelvic ultrasound demonstrated enlarged multiseptated ovaries (volume ranging 27-442cm3). Ascites was noted in one woman. Six women had visual field defects due to optic chiasm compression on formal assessment. Median FSH was 26.10 u/L (8.3-33), but LH was <2.5 u/L in all cases. Estradiol (E2) far exceeded the reference range in 5/7 women (2990 to > 18000pmol/L);E2 was at the upper limit of normal in the remaining 2/7 women (960-1450pmol/L). Hyperprolactinaemia, hyperthyroidism and other pituitary hormones deficiency were noted in 6/7, 1/7 and 4/7 women respectively. All FGAs were macroadenomas with diameters ranging 16-48mm. Two patients were administered a somatostatin analogue prior to surgery, but FSH, E2 and tumour size did not change. Transsphenoidal surgery was performed in 6/7 women, and always improved symptomatic and biochemical features of OHSS; however, residual FGA tumour was present post-operatively in all cases studied.

Limitations, reasons for caution

It is possible that some ‘non-functioning’ gonadotroph adenomas cause subclinical problems including menstrual irregularity and mild OHSS which were never diagnosed.

We have insufficient data to determine the prognosis for future pregnancy after FGA-induced OHSS.

This study utilised historical case-notes, so some data is missing.

Wider implications of the findings

The ‘spontaneous’ presentation of OHSS may be confusing for clinicians. We report that FGA is an important cause of spontaneous OHSS which has well-defined biochemical and radiological characteristics, which may be treated effectively in the short-to-medium with pituitary surgery. Results of this study may provide greater awareness of FGA-induced OHSS.

Trial registration number

N/A

O-252 Next generation sequencing analysis of the seminal microbiome in male partners of women with idiopathic recurrent pregnancy loss: results of a prospective cohort study

Study question

Is there an association between the semen microbiome, seminal reactive oxygen species (ROS) and DNA fragmentation in men with recurrent pregnancy loss (RPL)?

Summary answer

This pilot study outlines the subtle role that microbiota play in influencing ROS and sperm DNA damage for male partners of women with RPL

What is known already

RPL is defined as the loss of two or more consecutive pregnancies. This devastating condition impacts approximately 1% of couples. Paternal causes are not routinely screened for and an underlying cause is not found in up to 50% of cases. Recent studies have reported an association between elevated seminal ROS and sperm DNA fragmentation in the male partner, and RPL. We hypothesised that seminal microbiota contribute to increased ROS and sperm DNA damage. To test this, we investigated the relationship between seminal bacterial composition and ROS levels in men with proven fertility versus men with a history of RPL.

Study design, size, duration

We conducted a prospective, case-control study and recruited participants between November 2018 and March 2020 at Imperial College Healthcare NHS Trust. A total of 109 men participated in the study; 46 men with RPL and 63 men with proven fertility and no history of RPL. Each participant attended for a single study visit which consisted of a full medical history, assessment of testicular volume, height, weight, blood samples and production of a semen sample.

Participants/materials, setting, methods

Routine semen analysis (WHO) and endocrine and lipid profiles were performed for all patients. Semen ROS and DNA fragmentation were performed (luminol and TUNEL methodologies, respectively). ROS were classified as high (>3.77 RLU/s) or low (<3.77 RLU/s). Metataxonomic profiling of samples was performed using Illumina Miseq-based sequencing of the V1-V2 hypervariable regions of bacterial 16S rRNA gene amplicons. Multivariate and univariate modelling was performed to explore associations between metataxonomic profiles, ROS levels and clinical metadata.

Main results and the role of chance

Men with RPL had higher mean semen volume (p = 0.02) and increased prevalence of high ROS (p = 0.02, Fisher's exact) compared with controls; but other clinical characteristics were similar between groups. A total of 3,700,136 high quality sequence reads were generated for the dataset with an average of 33,946 reads/sample. Hierarchical clustering of bacterial genera relative abundances identified 4 distinct microbial signatures characterised by high relative abundance of 1. Streptococcus, 2. Lactobacillus and Gardnerella, 3. polymicrobial (including Prevotella), and 4. Corynebacterium and Finegoldia. Prevalences of these groups were similar in control and RPL groups (p = 0.11). Additionally, no association between the bacterial genera groups and elevated ROS, DNA fragmentation, or clinical factors such as age, ethnicity, or semen volume were observed (chi-square tests). At species taxonomy level relative abundance of L. crispatus was higher in controls compared to RPL, but did not withstand false discovery rate correction for multiple testing (p = 0.006, q = 0.67). Higher relative abundance of Microbacterium was detected in semen samples with high DNA fragmentation (p = 8.7E-4, q = 0.08). This relationship was even stronger within the RPL cohort (p = 2.8E-5, q = 0.002). No significant enrichment of specific taxa was observed between high or low ROS samples however, low ROS was associated with Corynebacterium relative abundance >20%.

Limitations, reasons for caution

More patients are required to enhance statistical power. Duplicate sample collection may establish the robustness of seminal compositions observed. Time since last sexual intercourse samples may affect the analysis. Concomitant analysis of the vaginal microbiome of female partners may improve our understanding of how partners may affect each other’s fertility.

Wider implications of the findings

Our data suggests interactions between microbiota composition, ROS and sperm DNA damage which may be implicated in the pathogenesis of recurrent miscarriage. Further studies are needed to determine if seminal microbiota play causal roles in RPL, and whether interventions modifying the seminal microbiome may modify pregnancy outcomes in affected couples

Trial registration number

not applicable

A comparison of the performance of ⁶⁸Ga-DOTATATE PET/CT and ¹²³I-MIBG SPECT in the diagnosis and follow-up of phaeochromocytoma and paraganglioma

PURPOSE

To compare the sensitivity of (123)I-metaiodobenzylguanidine (MIBG) SPECT and (68)Ga-DOTATATE PET/CT in detecting phaeochromocytomas (PCC) and paragangliomas (PGL) in the initial diagnosis and follow-up of patients with PCC and PGL disease.

METHODS

Retrospective analysis of 15 patients with PCC/PGL who had contemporaneous (123)I-MIBG and (68)Ga-DOTATATE imaging.

RESULTS

Of the 15 patients in the series, 8 were concordant with both modalities picking up clinically significant lesions. There were no patients in whom both modalities failed to pick up clinically significant lesions. There was discordance in seven patients: 5 had positive (68)Ga-DOTATATE and negative (123)I-MIBG, and 2 (12 and 14) had negative (68)Ga-DOTATATE and positive (123)I-MIBG. Utilizing (123)I-MIBG as the gold standard, (68)Ga-DOTATATE had a sensitivity of 80 % and a positive predictive value of 62 %. The greatest discordance was in head and neck lesions, with the lesions in 4 patients being picked up by (68)Ga-DOTATATE and missed by (123)I-MIBG. On a per-lesion analysis, cross-sectional (CT and MRI) and (68)Ga-DOTATATE was superior to (123)I-MIBG in detecting lesions in all anatomical locations, and particularly bony lesions.

CONCLUSION

First, (68)Ga-DOTATATE should be considered as a first-line investigation in patients at high risk of PGL and metastatic disease, such as in the screening of carriers for mutations associated with familial PGL syndromes. Second, if (123)I-MIBG does not detect lesions in patients with a high pretest probability of PCC or PGL, (68)Ga-DOTATATE should be considered as the next investigation. Third, (68)Ga-DOTATATE hould be considered in preference to (123)I-MIBG in patients in whom metastatic spread, particularly to the bone, is suspected.