Corticotroph cell hyperplasia as a rare cause of ACTH-dependent Cushing syndrome.

OBJECTIVE: Our aim was to characterise a cohort of patients with Cushing's disease (CD) who did not present pituitary adenoma in magnetic resonance imaging (MRI), needing a catheterisation of the inferior petrosal sinus (CIPS), and to study the pathological findings of the pituitary gland in these subjects after transsphenoidal surgery in order to establish the aetiology of CD. Furthermore, we evaluated possible differences in the features of the diagnosis between hyperplasia and adenoma. SUBJECTS AND METHODS: We included 16 subjects. 17 CIPS were done. Hormonal parameters were measured using standard methods. A microscopic histochemical study following standard procedures and immunohistochemical analysis was performed. The diagnostic criteria for adenoma and hyperplasia were based on the WHO classification. RESULTS: One patient was excluded for presenting an ACTH-producing bronchial neuroendocrine tumour. The 15 subjects with CD have a positive CIPS test indicating hypophyseal ACTH production. After transsphenoidal surgery, 12 patients showed a microadenoma and three (20%) a corticotroph cell hyperplasia. We found four recurrences after the transsphenoidal surgery (26%), with a mean time for recurrence of 105 months. We found that recurrence was more frequent in subjects with hyperplasia, and in those subjects with lower right/left ACTH ratio. CONCLUSION: Our study, which was focused on patients with CD with no pituitary adenoma detected by MRI and a positive CRH test after CIPS, has found that 20% showed corticotroph cell hyperplasia as the cause of CD. Right/left ACTH ratio after CIPS was useful to differentiate adenoma from hyperplasia. This finding may have important prognostic and treatment implications. More studies are necessary to confirm our result.

Indications of PCSK9 inhibitors in clinical practice. Recommendations of the Spanish Sociey of Arteriosclerosis (SEA), 2019. / Indicaciones de los inhibidores de PCSK9 en la práctica clínica. Recomendaciones de la Sociedad Española de Arteriosclerosis (SEA), 2019.

A group of experts convened by the Spanish Society of Arteriosclerosis (SEA) has been in charge of updating the SEA document on the indications of PCSK9 inhibitors (PCSK9i) in clinical practice that was published in 2016. This update is justified by the fact that the data from clinical trials carried out on a large scale with PCSK9i have shown that in addition to their high potency to lower atherogenic cholesterol, they reduce the risk of atherosclerotic cardiovascular disease, both in patients with stable disease, and with recent disease, and with a high degree of security. This update provides the recommendations and level of evidence for the prescription of iPCSK9 in patients with homozygous and heterozygous familial hypercholesterolemia, with atherosclerotic cardiovascular disease, and in primary prevention in patients with very high cardiovascular risk. These recommendations have been established taking into account the concentration of LDL-C, the clinical situation of the patient, the additional risk factors and the cost-effectiveness of their use.

Management of homozygous familial hypercholesterolaemia in two brothers.

Homozygous familial hypercholesterolaemia (HoFH) is a rare, genetic disorder of abnormally high levels of low-density lipoprotein cholesterol (LDL-C) requiring aggressive interventions to retard the evolution of atherosclerotic cardiovascular disease. We treated two brothers (ages 46 years and 47 years) with HoFH with statins, lipoproteinapheresis (LA) and the microsomal triglyceride transfer protein inhibitor lomitapide. Both brothers carried the p.Thr434Arg homozygous LDLR mutation and had childhood total cholesterol levels >700 mg/dL. Inter-LA LDL-C levels remained high; therefore, they were given escalating doses of oral lomitapide (5-10 mg/day). One brother was able to maintain LDL-C levels <70 mg/dL and stop LA. Lomitapide was well tolerated, with only an episode of headache requiring dose reduction from 40 mg/day to 20 mg/day in one patient. In two HoFH cases, lomitapide was an effective and well-tolerated adjunct therapy. Lomitapide doses required to maintain LDL-C goal levels appear to be lower in clinical practice than in clinical trials.

Anthropometric parameters and permanent remission of comorbidities 10 years after open gastric bypass in a cohort with high prevalence of super-obesity.

BACKGROUND AND AIM: Roux-en-Y gastric bypass (RYGB) is an effective treatment for weight loss in patients with morbid obesity. However, few studies have assessed its long-term efficacy in super-obese patients. The study objective was to analyse the long-term effectiveness of RYGB and its effect on improvement of comorbidities after 10 years of follow-up, and to compare the results depending on baseline BMI (<50kg/m2 vs ≥50kg/m2). PATIENTS AND METHODS: A retrospective study was conducted in 63 patients referred for RYGB with a 10-year or longer follow-up period. Mean BMI before surgery was 55kg/m2. RESULTS: Mean BMI decreased to 38.1kg/m2 at 10 years of follow-up. The success rates according to Reinhold criteria modified by Christou and to Biron's criteria were 30.2% and 54% respectively. The corresponding rates in super-obese patients were 21.4% and 57.1%. Significant, stable improvement was seen in diabetes, dyslipidemia, hypertension, and sleep apnea. CONCLUSIONS: Sustained weight loss was achieved after gastric bypass, with a mean excess weight loss of 50.6% after 10 years despite the high prevalence of super-obesity. Comorbidity improvement was maintained.

Value of the Definition of Severe Familial Hypercholesterolemia for Stratification of Heterozygous Patients.

Familial hypercholesterolemia (FH) is characterized by high low-density lipoprotein (LDL) cholesterol with co-dominant transmission and high risk of cardiovascular disease (CVD), although with high variability among subjects. Currently, CVD stratification tools for heterozygous FH (HeFH) are not available. A definition of severe HeFH has been recently proposed by the International Atherosclerosis Society (IAS), but it has not been validated. Our study aims to see clinical characteristics and prevalence of CVD in subjects defined as severe HeFH by IAS criteria. Probable or definite HeFH introduced in the Dyslipidemia Registry of Spanish Arteriosclerosis Society were analyzed by the IAS criteria. Univariate and multivariate analysis was used to assess the association of CVD with the IAS criteria. About 1,732 HeFH cases were analyzed. Severe HeFH had higher prevalence of familial history of CVD, personal history of tendon xanthomas, LDL cholesterol, and CVD than nonsevere HeFH. A total of 656 (77.1%) and 441 (50.1%) of men and women, respectively, fulfilled the IAS criteria of severe HeFH. In the univariate analysis, subjects defined as severe HeFH showed odds ratio 3.016 (95% CI 3.136 to 4.257, p <0.001) for CVD. However, when traditional risk factors were included in the multivariate analysis, only the presence of cholesterol >400 mg/dl had a statistically significant association with CVD odds ratio 8.76 (95% CI 3.90 to 19.69, p <0.001). In conclusion, the IAS definition of severe HeFH is not significantly associated with CVD when adjusted for classic risk factors. Risk stratification in HeFH is an important issue, but the proposed criteria do not seem to solve this problem.

Insulin resistance aggravates atherosclerosis by reducing vascular smooth muscle cell survival and increasing CX3CL1/CX3CR1 axis.

AIMS: Insulin resistance (IR) is a major risk factor for cardiovascular disease and atherosclerosis. Life-threatening acute events are mainly due to rupture of unstable plaques, and the role of vascular smooth muscle cells (VSMCs) in this process in IR, Type 2 diabetes mellitus, and metabolic syndrome (T2DM/MetS) has not been fully addressed. Therefore, the role of VSMC survival in the generation of unstable plaques in T2DM/MetS and the involvement of inflammatory mediators was investigated. METHODS AND RESULTS: Defective insulin receptor substrate 2 (IRS2)-mediated signalling produced insulin-resistant VSMCs with reduced survival, migration, and higher apoptosis than control cells. Silencing of IRS2 or inhibition of the V-akt murine thymomaviral oncogene homologue kinase (AKT)-extracellular signal-regulated kinase (ERK)-dependent pathway in VSMCs augmented expression of the inflammatory chemokine fractalkine (CX3CL1) and its receptor CX3CR1, previously involved in atheroma plaque vulnerability. Interestingly, treatment of VSMCs with CX3CL1 promoted apoptosis in the presence of other stimuli or when the AKT pathway was blocked. Analysis of a mouse model of IR-MetS and accelerated atherosclerosis, apoE-/-Irs2+/- mice, showed reduced VSMC survival, unstable plaques, and up-regulation of CX3CL1/CX3CR1 axis compared with apoE-/- mice. Human studies showed augmented soluble CX3CL1 plasma levels and CX3CR1 expression in monocytes from IR-MetS subjects compared with controls. A positive correlation between insulin levels, homeostatic model assessment (HOMA) index, carotid atherosclerosis, and CX3CR1 mRNA levels was also found in all patients. CONCLUSION: IR increases plaque vulnerability by augmenting the CX3CL1/CX3CR1 axis, which is mechanistically linked to reduced VSMC survival. Thus, modulation of IRS2-dependent signalling emerges as a potential therapeutic strategy to promote VSMC survival and atheroma plaque stability and to reduce inflammatory mediators in IR-MetS.

[Low-density lipoprotein apheresis in familial hypercholesterolemia resistant to intensive medical treatment]. / Aféresis de lipoproteínas de baja densidad en la hipercolesterolemia familiar resistente al tratamiento médico convencional intensivo.

BACKGROUND AND OBJECTIVE: The aim of our study is to analyze the effect and security of low-density lipoproteins (LDL) apheresis in familial hypercholesterolemia (FH) subjects who did not response to conventional intensive optimized medical treatment. PATIENTS AND METHODS: Seven heterozygous FH subjects and one homozygous apoB familial defective were studied. All subjects were on secondary prevention with highest statins doses in association with other hypolipemiant drugs; the mean LDL-C reduction was 20%. All of them were treated with LDL apheresis (immunoabsorption) for a mean of 4.25 years. RESULTS: LDL apheresis resulted in a 68.3% decrease in LDL-C and 58.2% in apoB plasma values (P<.001). After an average of 3 years of follow-up, the cardiovascular events disappeared in 4 out of 5 symptomatic patients while in one patient the events were reduced in 75%. Four moderate side effects were reported in 820 apheresis procedures. CONCLUSIONS: LDL apheresis is a well-tolerated and safe treatment in FH patients who do not response to intensive conventional optimized medical treatment. The main limitation is its economical cost and low accessibility.

A new PCSK9 gene promoter variant affects gene expression and causes autosomal dominant hypercholesterolemia.

CONTEXT: Autosomal dominant hypercholesterolemia (ADH) is a genetic disorder characterized by increased low-density lipoprotein (LDL)-cholesterol levels, leading to high risk of premature cardiovascular disease. More than 900 mutations in LDL receptor, six in APOB and 10 in PCSK9 have been identified as a cause of the disease in different populations. All known mutations in PCSK9 causing hypercholesterolemia produce an increase in the enzymatic activity of this protease. Up to now, there are data about the implication of PCSK9 in ADH in a low number of populations, not including a Spanish population. OBJECTIVE: The objective of the study was to study the prevalence of PCSK9 mutations in ADH Spanish population. PARTICIPANTS: We screened PCSK9 gene in 42 independent ADH patients in whom mutations in LDL receptor and APOB genes had been excluded. RESULTS: None of the known mutations causing ADH was detected in our sample, but we found two variations in the promoter region that could cause ADH, c.-288G>A and c.-332C>A (each in one proband). The analysis of the effect of these two variations on the transcription activity of the PCSK9 promoter showed that c.-288G>A did not modify the transcription, whereas c.-332C>A variant caused a 2.5-fold increase when compared with the wild-type sequence, either with or without lovastatin. CONCLUSIONS: PCSK9 is a rare cause of ADH in Spanish population and, up to what we know, none of the previously described mutations has been detected. We have identified a new mutation that could cause ADH by increasing the transcription of PCSK9.

Analysis of sequence variations in the LDL receptor gene in Spain: general gene screening or search for specific alterations?

BACKGROUND: Familial hypercholesterolemia (FH) is a frequent form of autosomal-dominant hypercholesterolemia that predisposes to premature coronary atherosclerosis. FH is caused by sequence variations in the gene coding for the LDL receptor (LDLR). This gene has a wide spectrum of sequence variations, and genetic diagnosis can be performed by 2 strategies. METHODS: Point variations and large rearrangements were screened along all the LDLR gene (promoter, exons, and flanking intron sequences). RESULTS: We screened a sample of 129 FH probands from the Valencian Community, Spain, and identified 54 different LDLR sequence variations. The most frequent (10% of cases) was 111insA, and 60% of the variants had a frequency as low as 1%. A previously described method for detection of known sequence variations in the Spanish population by DNA array analysis allowed the identification of only approximately 50% of patients with a variant LDLR gene and approximately 40% of the screened samples. CONCLUSION: Our results indicate that the adequate procedure to identify LDLR sequence variations in outbreed populations should include screening of the entire gene.