Pituitary Disease in AIP Mutation-Positive Familial Isolated Pituitary Adenoma (FIPA): A Kindred-Based Overview

Prolactin-secreting pituitary adenomas: male-specific differences in pathogenesis, clinical presentation and treatment

Prolactinomas (PRLomas) constitute approximately half of all pituitary adenomas and approximately one-fifth of them are diagnosed in males. The clinical presentation of PRLomas results from direct prolactin (PRL) action, duration and severity of hyperprolactinemia, and tumor mass effect. Male PRLomas, compared to females, tend to be larger and more invasive, are associated with higher PRL concentration at diagnosis, present higher proliferative potential, are more frequently resistant to standard pharmacotherapy, and thus may require multimodal approach, including surgical resection, radiotherapy, and alternative medical agents. Therefore, the management of PRLomas in men is challenging in many cases. Additionally, hyperprolactinemia is associated with a significant negative impact on men's health, including sexual function and fertility potential, bone health, cardiovascular and metabolic complications, leading to decreased quality of life. In this review, we highlight the differences in pathogenesis, clinical presentation and treatment of PRLomas concerning the male sex.

Genetic testing in prolactinomas: a cohort study

BACKGROUND

Prolactinomas represent 46%-66% of pituitary adenomas, but the prevalence of germline mutations is largely unknown. We present here the first study focusing on hereditary predisposition to prolactinoma.

OBJECTIVE

We studied the prevalence of germline mutations in a large cohort of patients with isolated prolactinomas.

MATERIALS AND METHODS

A retrospective study was performed combining genetic and clinical data from patients referred for genetic testing of MEN1, AIP, and CDKN1B between 2003 and 2020. SF3B1 was Sanger sequenced in genetically negative patients.

RESULTS

About 506 patients with a prolactinoma were included: 80 with microprolactinoma (15.9%), 378 with macroprolactinoma (74.7%), 48 unknown; 49/506 in a familial context (9.7%). Among these, 14 (2.8%) had a (likely) pathogenic variant (LPV) in MEN1 or AIP, and none in CDKN1B. All positive patients had developed a macroprolactinoma before age 30. The prevalence of germline mutations in patients with isolated macroprolactinoma under 30 was 4% (11/258) in a sporadic context and 15% (3/20) in a familial context. Prevalence in sporadic cases younger than 18 was 15% in men (5/33) and 7% in women (4/57). No R625H SF3B1 germline mutation was identified in 264 patients with macroprolactinomas.

CONCLUSIONS

We did not identify any LPVs in patients over 30 years of age, either in a familial or in a sporadic context, and in a sporadic context in our series or the literature. Special attention should be paid to young patients and to familial context.

Alcohol intake and risk of pituitary adenoma

BACKGROUND

The association between alcohol intake and incidence of pituitary adenoma has not been reported previously. We examined this association in three large, prospective cohort studies.

METHODS

Using data from the Nurses' Health Study, Nurses' Health Study II, and Health Professionals Follow-Up Study, we computed multivariable-adjusted hazard ratios (MVHR) and 95% confidence intervals (CI) for pituitary adenoma by levels of alcohol intake using Cox proportional hazards regression.

RESULTS

We identified 292 incident cases of pituitary adenoma (225 among women, 67 among men) among 235,973 participants with 6,548,732 person-years of follow-up. Compared with intake of ≤ 0.5 g/day, cumulative average alcohol intake in all categories was associated with reduced risk of pituitary adenoma (MVHR = 0.60, 95% CI 0.43-0.83 for 0.5-≤ 2 g/day, MVHR = 0.57, 95% CI 0.41-0.79 for > 2.0-≤ 8.0, MVHR = 0.70, 95% CI 0.47-1.04 for > 8.0-≤ 15.0, and MVHR = 0.51, 95% CI 0.32-0.83 for > 15.0 g/day). Significant inverse findings were present in women and were similar but non-significant in men. For specific alcoholic beverages, inverse associations were statistically significant for total wine (MVHR = 0.58, 95% CI 0.43-0.79 comparing 0.5-≤ 2 to ≤ 0.5 g/day), red wine (MVHR = 0.65, 95% CI 0.46-0.92 comparing 0.5-≤ 2 to ≤ 0.5 g/day), and white wine (MVHR = 0.72, 95% CI 0.53-0.97 comparing 0.5-≤ 2 to ≤ 0.5 g/day). Results were consistent using baseline intake, recent intake, and with an 8-year lag.

CONCLUSION

In three prospective cohorts, compared to almost no consumption, alcohol consumption was associated with reduced risk of pituitary adenoma. Sensitivity analyses suggest that these results are unlikely to be the result of reverse causation or diagnostic bias.

Management of prolactinomas in children and adolescents; which factors define the response to treatment?

PURPOSE

Prevalence, presentation and clinical outcome of prolactinomas vary in children and adults. In this study, we evaluated the clinical features and outcome of children and adolescents with prolactinoma to identify the differences from that of adults, and thus to establish the management strategies for this age group.

METHODS

Patients with prolactinoma diagnosed before 18 years of age from a single center in the last 20-years were included. Clinical and laboratory data, radiological findings and treatment outcome were evaluated retrospectively.

RESULTS

Twenty-eight patients (23 female; 82.1%) with prolactinoma were included. Median age at diagnosis was 15.2 years (12.6-17.7 years) in girls, 12.9 years (12.0-16.7 years) in boys. First line treatment was cabergoline in 82% of patients and normal prolactin level was achieved with maximum dose of 2 mg/week in 78%. Surgery was required in 28% of patients. Adenomas < 13.5 mm responded conventional doses of CAB. Adenomas > 30 mm were drug resistant or required surgery. Adenomas between 13.5 mm and 30 mm with invasion/extension were more likely to have drug resistance. CAB had to be continued following surgery in all patients. One macroprolactinoma had an increase in size which was accompanied with increasing prolactin level.

CONCLUSIONS

All microprolactinomas responded well to DA treatment. However, all adenomas larger than 30 mm was resistant to CAB or required surgery. Probability of drug resistance and requirement of second line therapy were higher in adenomas between 13.5 mm and 30 mm with invasion/extension. Doses over 2 mg/week of CAB in drug-resistant patients may not provide additional benefit. The frequency of follow-up MRI could be determined based on prolactin levels and emergence of new neurological symptoms.

Mutations in Hsp90 Cochaperones Result in a Wide Variety of Human Disorders

The Hsp90 molecular chaperone, along with a set of approximately 50 cochaperones, mediates the folding and activation of hundreds of cellular proteins in an ATP-dependent cycle. Cochaperones differ in how they interact with Hsp90 and their ability to modulate ATPase activity of Hsp90. Cochaperones often compete for the same binding site on Hsp90, and changes in levels of cochaperone expression that occur during neurodegeneration, cancer, or aging may result in altered Hsp90-cochaperone complexes and client activity. This review summarizes information about loss-of-function mutations of individual cochaperones and discusses the overall association of cochaperone alterations with a broad range of diseases. Cochaperone mutations result in ciliary or muscle defects, neurological development or degeneration disorders, and other disorders. In many cases, diseases were linked to defects in established cochaperone-client interactions. A better understanding of the functional consequences of defective cochaperones will provide new insights into their functions and may lead to specialized approaches to modulate Hsp90 functions and treat some of these human disorders.