Effect on hospital incentive payments and quality performance of a hospital pay for performance (P4P) programme in Belgium.

BACKGROUND: Belgium initiated a hospital pay for performance (P4P) programme after a decade of fixed bonus budgets for "quality and safety contracts". This study examined the effect of P4P on hospital incentive payments, performance on quality measures, and the association between changes in quality performance and incentive payments over time. METHODS: The Belgian government provided information on fixed bonus budgets in 2013-2017 and hospital incentive payments as well as hospital performance on quality measures for the P4P programmes in 2018-2020. Descriptive analyses were conducted to map the financial repercussion between the two systems. A difference-in-difference analysis evaluated the association between quality indicator performance and received incentive payments over time. RESULTS: Data from 87 acute-care hospitals were analyzed. In the transition to a P4P programme, 29% of hospitals received lower incentive payments per bed. During the P4P years, quality performance scores increased yearly for 55% of hospitals and decreased yearly for 5% of hospitals. There was a significant larger drop in incentive payments for hospitals that scored above median with the start of the P4P programme. CONCLUSIONS: The transition from fixed bonus budgets for quality efforts to a new incentive payment in a P4P programme has led to more hospitals being financially impacted, although the effect is marginal given the small P4P budget. Quality indicators seem to improve over the years, but this does not correlate with an increase in reward per bed for all hospitals due to the closed nature of the budget.

The FlaQuM-Quickscan: A starting point to include primary care professionals' perspectives in the evaluation of hospital quality priorities.

INTRODUCTION: Today, primary care professionals' (PCPs) perspectives on hospital quality are unknown when evaluating hospital quality priorities. The aims of the present study were to identify key healthcare quality attributes from PCPs' perspective, to validate an instrument that measures PCPs' experiences of healthcare quality multidimensionally and to define hospital quality priorities based on PCPs' experiences. MATERIAL AND METHODS: Focus groups with PCPs were conducted to identify quality attributes through a qualitative in-depth analysis. A multicentre study of 18 hospitals was used to quantitatively assess construct, discriminant and criterion validity of the FlaQuM-Quickscan, an instrument that measures 'Healthcare quality for patients and kin' (part 1) and 'Healthcare quality for professionals' (part 2). To set quality priorities, scores on quality domains were analyzed descriptively and between-hospital variation was examined by evaluating differences in hospitals' mean scores on the quality domains using one-way Analysis of Variance (ANOVA). RESULTS: Identified key attributes largely corresponded with Lachman's multidimensional quality model. Including 'Communication' as a new quality domain was recommended. The FlaQuM-Quickscan was completed by 550 PCPs. Confirmatory factor analyses showed reasonable to good fit, except for the Root Mean Square Error of Approximation (RMSEA) in part 2. The 'Equity' domain scored the highest in parts 1 and 2. Domains 'Kin-centred care' and 'Accessibility and timeliness' scored the lowest in part 1 and 'Resilience' and 'Partnership and co-production' in part 2. Significant variation in hospitals' mean scores was observed for eleven domains in part 1 and sixteen domains in part 2. CONCLUSIONS: The results gained a better understanding of PCPs' perspective on quality. The FlaQuM-Quickscan is a valid instrument to measure PCPs' experiences of hospital quality. Identified priorities indicate that hospital management should focus on multifaceted quality strategies, including technical domains, person-and kin-centredness, core values and catalysts.

Androgen therapy does not prevent bone loss and arterial calcifications in male rats with chronic kidney disease.

Patients suffering from chronic kidney disease (CKD) often experience bone loss and arterial calcifications. It is unclear if hypogonadism contributes to the development of these complications and whether androgen therapy might prevent them. Male adult rats were randomized into four groups. The first group received standard chow (control), while three other groups were fed a 0.25% adenine/low vitamin K diet (CKD). Two CKD groups were treated with testosterone or dihydrotestosterone (DHT), whereas the control group and one CKD group received vehicle (VEH). CKD animals had 10-fold higher serum creatinine and more than 15-fold higher parathyroid hormone levels compared to controls. Serum testosterone levels were more than two-fold lower in the CKDVEH group compared to control + VEH and CKD + testosterone groups. Seminal vesicle weight was reduced by 50% in CKDVEH animals and restored by testosterone and DHT. CKD animals showed a low bone mass phenotype with decreased trabecular bone volume fraction and increased cortical porosity, which was not rescued by androgen treatment. Aortic calcification was much more prominent in CKD animals and not unequivocally prevented by androgens. Messenger RNA expression of the androgen receptor-responsive genes Acta1 and Col1a1 was reduced by CKD and stimulated by androgen treatment in levator ani muscle but not in the bone or aortic tissue. We conclude that adenine-induced CKD results in the development of hypogonadism in male rats. Androgen therapy is effective in restoring serum testosterone levels and androgen-sensitive organ weights but does not prevent bone loss or arterial calcifications, at least not in the presence of severe hyperparathyroidism.

Role of sex hormone-binding globulin in the free hormone hypothesis and the relevance of free testosterone in androgen physiology.

According to the free hormone hypothesis, biological activity of a certain hormone is best reflected by free rather than total hormone concentrations. A crucial element in this theory is the presence of binding proteins, which function as gatekeepers for steroid action. For testosterone, tissue exposure is governed by a delicate equilibrium between free and total testosterone which is determined through interaction with the binding proteins sex hormone-binding globulin and albumin. Ageing, genetics and various pathological conditions influence this equilibrium, hereby possibly modulating hormonal exposure to the target tissues. Despite ongoing controversy on the subject, strong evidence from recent in vitro, in vivo and human experiments emphasizes the relevance of free testosterone. Currently, however, clinical possibilities for free hormone diagnostics are limited. Direct immunoassays are inaccurate, while gold standard liquid chromatography with tandem mass spectrometry (LC-MS/MS) coupled equilibrium dialysis is not available for clinical routine. Calculation models for free testosterone, despite intrinsic limitations, provide a suitable alternative, of which the Vermeulen calculator is currently the preferred method. Calculated free testosterone is indeed associated with bone health, frailty and other clinical endpoints. Moreover, the added value of free testosterone in the clinical diagnosis of male hypogonadism is clearly evident. In suspected hypogonadal men in whom borderline low total testosterone and/or altered sex hormone-binding globulin levels are detected, the determination of free testosterone avoids under- and overdiagnosis, facilitating adequate prescription of hormonal replacement therapy. As such, free testosterone should be integrated as a standard biochemical parameter, on top of total testosterone, in the diagnostic workflow of male hypogonadism.

Single-cell ATAC and RNA sequencing reveal pre-existing and persistent cells associated with prostate cancer relapse.

Prostate cancer is heterogeneous and patients would benefit from methods that stratify those who are likely to respond to systemic therapy. Here, we employ single-cell assays for transposase-accessible chromatin (ATAC) and RNA sequencing in models of early treatment response and resistance to enzalutamide. In doing so, we identify pre-existing and treatment-persistent cell subpopulations that possess regenerative potential when subjected to treatment. We find distinct chromatin landscapes associated with enzalutamide treatment and resistance that are linked to alternative transcriptional programs. Transcriptional profiles characteristic of persistent cells are able to stratify the treatment response of patients. Ultimately, we show that defining changes in chromatin and gene expression in single-cell populations from pre-clinical models can reveal as yet unrecognized molecular predictors of treatment response. This suggests that the application of single-cell methods with high analytical resolution in pre-clinical models may powerfully inform clinical decision-making.

Molecular underpinnings of enzalutamide resistance

Prostate cancer (PCa) is among the most common adult malignancies, and the second leading cause of cancer-related death in men. As PCa is hormone dependent, blockade of the androgen receptor (AR) signaling is an effective therapeutic strategy for men with advanced metastatic disease. The discovery of enzalutamide, a compound that effectively blocks the AR axis and its clinical application has led to a significant improvement in survival time. However, the effect of enzalutamide is not permanent, and resistance to treatment ultimately leads to development of lethal disease, for which there currently is no cure. This review will focus on the molecular underpinnings of enzalutamide resistance, bridging the gap between the preclinical and clinical research on novel therapeutic strategies for combating this lethal stage of prostate cancer.

Free Testosterone Reflects Metabolic as well as Ovarian Disturbances in Subfertile Oligomenorrheic Women.

BACKGROUND: Diagnosing polycystic ovary syndrome (PCOS) is based on ovulatory dysfunction, ovarian ultrasound data, and androgen excess. Total testosterone is frequently used to identify androgen excess, but testosterone is mainly bound to sex hormone-binding globulin (SHBG) and albumin. Only 1-2% of nonprotein-bound testosterone (so-called free testosterone) is biologically active and responsible for androgen action. Moreover, automated immunoassays which are frequently used for female testosterone measurements are inaccurate. OBJECTIVE: To assess the clinical usefulness of liquid chromatography-tandem mass spectrometry measured testosterone and calculated free testosterone in subfertile women attending a fertility clinic with oligomenorrhea and suspected PCOS. METHODS: Hormonal and metabolic parameters were evaluated, and ovarian ultrasound was performed. Total testosterone was measured by liquid chromatography-tandem mass spectrometry. Free testosterone was calculated from total testosterone and SHBG. RESULTS: Sixty-six women were included in the study. Total testosterone was associated with ovarian volume and antral follicle count but not with metabolic parameters. However, SHBG and calculated free testosterone were associated with both ovarian ultrasound and metabolic parameters, such as BMI and insulin resistance. CONCLUSIONS: Assessing SHBG and free testosterone is important in evaluating androgen excess in subfertile women with ovulatory dysfunction and suspected PCOS, as it reflects both ovarian and metabolic disturbances.

The role of TET-mediated DNA hydroxymethylation in prostate cancer.

Ten-eleven translocation (TET) proteins are recently characterized dioxygenases that regulate demethylation by oxidizing 5-methylcytosine to 5-hydroxymethylcytosine and further derivatives. The recent finding that 5hmC is also a stable and independent epigenetic modification indicates that these proteins play an important role in diverse physiological and pathological processes such as neural and tumor development. Both the genomic distribution of (hydroxy)methylation and the expression and activity of TET proteins are dysregulated in a wide range of cancers including prostate cancer. Up to now it is still unknown how changes in TET and 5(h)mC profiles are related to the pathogenesis of prostate cancer. In this review, we explore recent advances in the current understanding of how TET expression and function are regulated in development and cancer. Furthermore, we look at the impact on 5hmC in prostate cancer and the potential underlying mechanisms. Finally, we tried to summarize the latest techniques for detecting and quantifying global and locus-specific 5hmC levels of genomic DNA.

Treatment-induced changes in the androgen receptor axis: Liquid biopsies as diagnostic/prognostic tools for prostate cancer.

Prostate cancer progression and treatment relapse is associated with changes in the androgen receptor axis, and analysis of alternations of androgen receptor signaling is valuable for prognostics and treatment optimization. The profile of androgen receptor axis is currently obtained from biopsy specimens, which are not always easy to obtain. Moreover, the information acquired only provides a snapshot of the tumor biology, with strict spatial and temporal limitations. On the other hand, circulation is easily accessible source of both circulating tumor cells and circulating tumor DNA, which can be sampled at numerous time points. This Review will explore the potential use of androgen receptor axis alternations detectable in the blood in therapeutic decision-making and precision medicine for advancing metastatic castration-resistant prostate cancer.

The survival impact of neoadjuvant hormonal therapy before radical prostatectomy for treatment of high-risk prostate cancer.

BACKGROUND: Several randomized controlled trials assessed the outcomes of patients treated with neoadjuvant hormonal therapy (NHT) before radical prostatectomy (RP). The majority of them included mainly low and intermediate risk prostate cancer (PCa) without specifically assessing PCa-related death (PCRD). Thus, there is a lack of knowledge regarding a possible effect of NHT on PCRD in the high-risk PCa population. We aimed to analyze the effect of NHT on PCRD in a multicenter high-risk PCa population treated with RP, using a propensity-score adjustment. METHODS: This is a retrospective multi-institutional study including patients with high-risk PCa defined as: clinical stage T3-4, PSA >20 ng ml-1 or biopsy Gleason score 8-10. We compared PCRD between RP and NHT+RP using competing risks analysis. Correction for group differences was performed by propensity-score adjustment. RESULTS: After application of the inclusion/exclusion criteria, 1573 patients remained for analysis; 1170 patients received RP and 403 NHT+RP. Median follow-up was 56 months (interquartile range 29-88). Eighty-six patients died of PCa and 106 of other causes. NHT decreased the risk of PCRD (hazard ratio (HR) 0.5; 95% confidence interval (CI) 0.32-0.80; P=0.0014). An interaction effect between NHT and radiotherapy (RT) was observed (HR 0.3; 95% CI 0.21-0.43; P<0.0008). More specifically, of patients who received adjuvant RT, those who underwent NHT+RP had decreased PCRD rates (2.3% at 5 year) compared to RP (7.5% at 5 year). The retrospective design and lack of specific information about NHT are possible limitations. CONCLUSIONS: In this propensity-score adjusted analysis from a large high-risk PCa population, NHT before surgery significantly decreased PCRD. This effect appeared to be mainly driven by the early addition of RT post-surgery. The specific sequence of NHT+RP and adjuvant RT merits further study in the high-risk PCa population.

Lower bone turnover and relative bone deficits in men with metabolic syndrome: a matter of insulin sensitivity? The European Male Ageing Study.

We examined cross-sectional associations of metabolic syndrome and its components with male bone turnover, density and structure. Greater bone mass in men with metabolic syndrome was related to their greater body mass, whereas hyperglycaemia, hypertriglyceridaemia or impaired insulin sensitivity were associated with lower bone turnover and relative bone mass deficits. INTRODUCTION: Metabolic syndrome (MetS) has been associated with lower bone turnover and relative bone mass or strength deficits (i.e. not proportionate to body mass index, BMI), but the relative contributions of MetS components related to insulin sensitivity or obesity to male bone health remain unclear. METHODS: We determined cross-sectional associations of MetS, its components and insulin sensitivity (by homeostatic model assessment-insulin sensitivity (HOMA-S)) using linear regression models adjusted for age, centre, smoking, alcohol, and BMI. Bone turnover markers and heel broadband ultrasound attenuation (BUA) were measured in 3129 men aged 40-79. Two centres measured total hip, femoral neck, and lumbar spine areal bone mineral density (aBMD, n = 527) and performed radius peripheral quantitative computed tomography (pQCT, n = 595). RESULTS: MetS was present in 975 men (31.2 %). Men with MetS had lower ß C-terminal cross-linked telopeptide (ß-CTX), N-terminal propeptide of type I procollagen (PINP) and osteocalcin (P < 0.0001) and higher total hip, femoral neck, and lumbar spine aBMD (P ≤ 0.03). Among MetS components, only hypertriglyceridaemia and hyperglycaemia were independently associated with PINP and ß-CTX. Hyperglycaemia was negatively associated with BUA, hypertriglyceridaemia with hip aBMD and radius cross-sectional area (CSA) and stress-strain index. HOMA-S was similarly associated with PINP and ß-CTX, BUA, and radius CSA in BMI-adjusted models. CONCLUSIONS: Men with MetS have higher aBMD in association with their greater body mass, while their lower bone turnover and relative deficits in heel BUA and radius CSA are mainly related to correlates of insulin sensitivity. Our findings support the hypothesis that underlying metabolic complications may be involved in the bone's failure to adapt to increasing bodily loads in men with MetS.

Bone turnover markers predict hip bone loss in elderly European men: results of the European Male Ageing Study (EMAS).

SUMMARY: The aim of this study was to determine whether bone turnover markers (BTMs) predict changes in areal bone mineral density (aBMD) in middle-aged and elderly European men. Older men with high bone turnover are at a higher risk of accelerated hip bone loss, but the clinical utility of BTMs in individuals is limited. INTRODUCTION: Prospective studies on the value of BTMs to predict changes in aBMD in men are few and conflicting. The aim of this study was to determine whether BTMs predict changes in aBMD in middle-aged and elderly European men. METHODS: In 487 men aged 40-79 years from the European Male Ageing Study (EMAS), BTMs were assessed at baseline and dual-energy X-ray absorptiometry (DXA) at the lumbar spine (LS), femoral neck (FN) and total hip (TH) was performed at baseline and after a mean follow-up of 4.3 years. RESULTS: The mean aBMD decreased by 0.32%/year at FN and 0.22%/year at TH and increased by 0.32%/year at LS. Higher baseline levels of ß C-terminal cross-linked telopeptide (ß-CTX) and N-terminal propeptide of type I procollagen (PINP) were significantly associated with higher loss of hip aBMD in the whole cohort and men aged 60-79 years. These associations remained significant after adjustment for age, centre and body mass index (BMI). Men aged 60-79 years with ß-CTX in the upper quintile were more likely of being in the upper quintile of annual percentage (%) aBMD loss at FN (OR=4.27; 95% CI=2.09-8.73) and TH (OR=3.73; 95% CI=1.84-7.57). The positive predictive value (PPV) was 46% at both hip sites. CONCLUSION: Older men with high bone turnover have a higher risk of accelerated hip bone loss, but the PPV is low. BTMs are therefore unlikely to be of clinical utility in predicting accelerated hip bone loss in individual subjects.

The transcription intermediary factor 1ß coactivates the androgen receptor.

The androgen receptor (AR) is a ligand-inducible transcription factor. Its transcription activation domain consists of the two transcription activation units called Tau-1 and Tau- 5. Tau-5 interacts with p160 coactivators like the transcription intermediary factor 2 (TIF2), which in their turn recruit histone modifiers and chromatin-remodelling complexes. The mechanism of action of Tau-1, however, remains elusive. Here, we demonstrate that transcription intermediary factor 1ß (TIF1ß) can induce the activity of the AR up to five fold when tested in vitro. Although there is no evidence for direct interactions between TIF1ß and AR, mutation studies show that the activity of TIF1ß depends on the integrity of Tau-1 in AR on the one hand, and the so-called tripartite motif domain in TIF1ß on the other. Surprisingly, the coactivation by TIF1ß via Tau-1 seems additive rather than cooperative with the AR coactivation by TIF2. Some mutations naturally occurring in androgen-insensitivity syndrome patients that reside in Tau-1 seem to impair the TIF1ß coactivation of the AR, indicating that TIF1ß could also be relevant for the in vivo androgen response in humans. Moreover, since TIF1ß is well expressed in prostate cancer cells, its functional interaction with androgen signalling could in the long run be a therapeutic target for this disease.

Sarcopenia and its relationship with bone mineral density in middle-aged and elderly European men.

UNLABELLED: The aim of this study was to determine the relationship between reduced muscle mass (sarcopenia) and areal bone mineral density (BMD(a)) in middle-aged and elderly community-dwelling European men. Men with sarcopenia had significantly lower BMD(a) and were more likely to have osteoporosis compared with men without sarcopenia. INTRODUCTION: In men, the relationship between reduced muscle mass (sarcopenia) and BMD(a) is unclear. This study aimed to determine this relationship in middle-aged and elderly community-dwelling men. METHODS: Men aged 40-79 years from the Manchester (UK) and Leuven (Belgium) cohorts of the European Male Ageing Study were invited to attend for assessment including dual-energy X-ray absorptiometry, from which appendicular lean mass (aLM), fat mass (FM) and whole-body, spine and hip BMD(a) were determined. Relative appendicular skeletal muscle mass (RASM) was calculated as aLM/height². Muscle strength was assessed in subjects from Leuven. Sarcopenia was defined by RASM at <7.26 kg/m² and by the recent definition of the European Working Group on Sarcopenia in Older People (RASM at <7.26 kg/m(2) plus low muscle function). Linear regression was used to determine the associations between aLM, FM, muscle strength and BMD(a) and logistic regression to determine the association between sarcopenia and osteoporosis. RESULTS: Six hundred seventy-nine men with a mean age of 59.6 (SD = 10.7), contributed data to the analysis; 11.9 % were sarcopenic by the conventional definition. After adjustment for age and centre, aLM, RASM and FM were positively associated with BMD(a). Men with RASM at <7.26 kg/m² had significantly lower BMD(a) compared with those with RASM at ≥7.26 kg/m(2). In a multivariable model, aLM was most consistently associated with BMD(a). Men with sarcopenia were more likely to have osteoporosis compared with those with normal RASM (odds ratio = 3.0; 95 % CI = 1.6-5.8). CONCLUSIONS: Sarcopenia is associated with low BMD(a) and osteoporosis in middle-aged and elderly men. Further studies are necessary to assess whether maintaining muscle mass contributes to prevent osteoporosis.

Musculoskeletal frailty: a geriatric syndrome at the core of fracture occurrence in older age.

A progressive decline in physiologic reserves inevitably occurs with ageing. Frailty results from reaching a threshold of decline across multiple organ systems. By consequence, frail elderly experience an excess vulnerability to stressors and are at high risk for functional deficits and comorbid disorders, possibly leading to institutionalization, hospitalization and death. The phenotype of frailty is referred to as the frailty syndrome and is widely recognized in geriatric medical practice. Although frailty affects both musculoskeletal and nonmusculoskeletal systems, sarcopenia, which is defined as age-related loss of muscle mass and strength, constitutes one of the main determinants of fracture risk in older age and one of the main components of the clinical frailty syndrome. As a result, operational definitions of frailty and therapeutic strategies in older patients tend to focus on the consequences of sarcopenia.

7α-methyl-19-nortestosterone vs. testosterone implants for hypogonadal osteoporosis: a preclinical study in the aged male orchidectomized rat model.

Overt male hypogonadism induces not only osteoporosis but also unfavourable changes in body composition, which can be prevented by testosterone (T) replacement. In this preclinical study, the potential of synthetic androgen 7α-methyl-19-nortestosterone (MENT) as alternative treatment for male hypogonadism was evaluated in comparison with T. Eleven-month-old male rats were orchidectomized (orch) and left untreated for 2-months. Subsequently, the effects of 4-month MENT (12 µg/day) and T (72 µg/day) treatment on bone, muscle and fat were analysed using microcomputed tomography, dual-energy X-ray absorptiometry, dynamic bone histomorphometry and muscle fibre typing. At the onset of treatment, orch rats were clearly hypogonadal. This was evidenced by significant reductions of androgen-sensitive organ weight, lean mass, cortical thickness and trabecular bone volume compared with sham-operated aged-matched controls (sham). MENT and T restored weight of androgen-sensitive organs to a similar extent, with a superior anabolic action of MENT on levator ani muscle. Both androgens not only fully rescued hypogonadal loss of lean mass but also restored muscle fibre type composition and trabecular bone volume. Cortical bone loss was similarly prevented by MENT and T, but without full recovery to sham. Both androgens stimulated periosteal bone formation, but with a stronger effect of T. By contrast, MENT more strongly suppressed endocortical bone formation and bone turnover rate and reduced fat mass and serum leptin to a greater extent than T. MENT and T are both effective replacement therapies to stimulate bone and muscle in hypogonadal rats, with stronger lipolytic action of MENT.

Androgen receptor knockout and knock-in mouse models.

Androgens play an important role in male reproductive development and function. These steroid hormones mediate their actions by binding to the androgen receptor (AR). Diseases such as androgen insensitivity syndrome, prostate cancer, Kennedy's disease, and infertility can be caused by mutations in the AR. To get a better insight into the molecular working mechanisms of the AR, several knockout and knock-in mouse models have been developed. These models are reviewed here and are compared with human diseases.

Influence of nucleophosmin/B23 on DNA binding and transcriptional activity of the androgen receptor in prostate cancer cell.

The promotion and progression of prostate cancer (PCa) are associated with androgen receptor (AR) signalling. AR functions are modulated by a variety of co-factors amongst which we identified the nucleophosmin (NPM/B23), a member of the histone chaperone family. Here, we show that NPM is overexpressed in PCa compared to normal adjacent tissues. AR and NPM interact in vitro and in vivo, and NPM is critical for androgen-dependent transcriptional activation in LNCaP cells as an anti-NPM siRNA downregulates transcription of a transfected androgen response element (ARE)-containing reporter promoter as well as expression of the endogenous androgen responsive prostate-specific antigen (PSA) gene. By investigating the effect of NPM on AR, we have also observed that NPM enhances AR binding to an ARE in vitro in electrophoretic gel mobility-shift assay experiments. Chromatin immunoprecipitation studies further demonstrated that both AR and NPM associate with AREs of the PSA gene in vivo. Altogether, our data suggest that the molecular histone chaperone NPM could regulate AR functions by promoting assembly of AR-containing regulatory complexes and that high levels of NPM might alter AR functions in PCa.

Detailed functional studies on androgen receptor mild mutations demonstrate their association with male infertility.

CONTEXT: Mutations in the androgen receptor (AR) gene can cause the androgen insensitivity syndrome (AIS). For complete and severe partial AIS, well-characterized in vitro functional assays can be used for genotype-phenotype correlation; however, for mild forms of AIS, as associated with male infertility, experimental evidence is scarce or lacking. In particular, optimal in vitro functional tests informative about the genotype-phenotype relation have not been described. OBJECTIVE: The objective of this study was to investigate the association among genotype and phenotype for AR mutations found in infertile males by conventional functional assays and additional in-depth studies performed with several gene reporters. DESIGN: To this aim, we selected four AR missense mutations associated with isolated male infertility (L547F and two novel mutations A474V and S650G) or partial AIS (Y571H). After introduction of the specific mutations in AR expression plasmid, we performed classical in vitro studies (Western immunoblotting, electrophoretic mobility shift assay, hormone-response curves) and transactivation assays with different reporter constructs (MMTV, Sc-ARU-TK, TAT-GRE- 2X, Slp-ARU-TK and PEM). RESULTS AND CONCLUSIONS: Our results showed that standard functional tests provide sufficient information only for severe AR mutations, whereas for AR mutations found in mild AIS patients with male infertility, only an extensive analysis with different in vitro systems, and in particular with PEM promoter, can give information on the functionality of the AR and therefore on the pathogenicity of the mutations and on genotype-phenotype correlation.