Ornella Ludovico

Adrenocortical Oncocytic Tumors: Report of 10 Cases and Review of the Literature

Ten additional adrenocortical oncocytic tumors are presented: 2 benign oncocytomas, 4 borderline oncocytomas of uncertain malignant potential, and 4 oncocytic carcinomas. Histologically all tumors were entirely or predominantly composed of oncocytes. Immunohistochemically all tumors were immunoreactive for mitochondrial antigen mES-13. Electron microscopy was performed in 8 cases and was confirmatory of the oncocytic cell change. The morphologic parameters of the Weiss system, considered to be predictive of the biologic behavior of conventional (nononcocytic) adrenocortical tumors, are reviewed in the context of their possible application to the oncocytic tumor variant. Proposed major criteria (high mitotic rate, atypical mitoses, venous invasion) and minor criteria (large size and huge weight, necrosis, capsular invasion, sinusoidal invasion) in distinguishing malignant tumors are discussed, and definitional criteria (predominantly cells with eosinophilic and granular cytoplasm, high nuclear grade, diffuse architectural pattern) in common with all types of oncocytic tumors are outlined. The authors’ proposed working rules for diagnostic categorization of oncocytic adrenocortical tumors are defined, with the presence of 1 major criterion indicating malignancy, 1 to 4 minor criteria indicating uncertain malignant potential (borderline), and the absence of all major and minor criteria indicative of benignancy. Using these criteria, the diagnosis of malignancy was straightforward in 3 of the 4 cases designated as oncocytic carcinoma (presence of at least 2 major criteria and all the minor criteria), while in 1 case the original diagnosis of benign oncocytoma was reversed to malignant following critical review of the original pathologic material after local tumor recurrence. Tumor recurrence occurred in 2 carcinomas at 8 and 20 months, respectively, and was followed in 1 case by the patient’s death. The third patient expired at 6 months from unrelated causes, and the fourth patient is free of disease at the relatively short follow-up interval of 6 months. Regarding the 4 patients with borderline tumors, all are alive with no evidence of disease, with follow-up ranging from 10 to 61 months (mean 38.7 months). The 2 benign tumors have a follow-up of 25 and 30 months, respectively. Diagnostic difficulties are delineated and a complete review of the literature on this topic has also been performed.

Heterogeneous Effect of Peroxisome Proliferator-activated Receptor γ2 Ala12 Variant on Type 2 Diabetes Risk

Conflicting results have been reported regarding whether the PPARγ2 Pro12Ala polymorphism plays a role in the risk of type 2 diabetes (T2D), suggesting genetic heterogeneity. To investigate this issue, a meta‐analysis of 41 published and 2 unpublished studies (a total of 42,910 subjects) was conducted. Ala12 carriers had a 19% T2D risk reduction, but this association was highly heterogeneous (p = 0.005). A great proportion (48%) of heterogeneity was explained by the controls’ BMI, with risk reduction being greater when BMI was lower. Risk reduction of Ala12 carriers in Asia (35%) was higher than in Europe (15%, p = 0.02) and tended to be higher than in North America (18%, p = 0.10). Difference between Asians and Europeans was no longer significant (p = 0.15) after adjusting for the controls’ BMI. Studies from Europe were still heterogeneous (p = 0.02) with risk reduction in Ala12 carriers being progressively smaller (test for trend in the odds ratios, p = 0.02) from Northern (26% reduction, p < 0.0001) to Central (10%, p = 0.04) and Southern (0%, p = 0.94) Europe. In conclusion, in our meta‐analysis, the reduced risk of T2D in Ala12 carriers is not homogeneous. It is greater in Asia than in Europe and, among Europeans, it is higher in Northern Europe, barely significant in Central Europe, and nonexistent in Southern Europe.

Interaction Between PPARγ2 Variants and Gender on the Modulation of Body Weight

Conflicting results have been reported regarding the effect of the peroxisome proliferator‐activated receptor‐γ−2 (PPARγ2) Pro12Ala polymorphism, (singly or in combination with the silent C1431T polymorphism) on BMI. Gender‐based dimorphism has been evidenced for genes that affect BMI, but few and conflicting data are available regarding PPARγ2. We sought to investigate whether the Pro12Ala interacts with gender in modulating BMI in 566 nondiabetic unrelated white subjects (men:women = 211:355, age 36.59 ± 11.85; BMI 25.36 ± 4.53). In the whole study population, BMI, fasting glucose and insulin levels, and lipid profile were similar in Ala12 carriers (i.e., XA) and Pro/Pro homozygous subjects. Among the men, but not among the women, X/Ala individuals showed higher BMI (25.9 ± 3.6 vs. 28.2 ± 4.9, P = 0.006) and risk of obesity (odds ratio = 2.85, 95% confidence interval = 1.07–7.62). A significant gene‐gender interaction in modulating BMI was observed (P = 0.039). Among the men, but not among the women, those carrying Ala‐T haplotype (i.e., containing both Ala12 and T1431 variants) showed the highest BMI (haplo‐score = 3.72, P = 0.0014). Our data indicate that in whites from Italy the PPARγ2 Pro12Ala polymorphism interacts with gender in modulating BMI, thereby replicating some, but not all, earlier data obtained in different populations. Whether the PPARγ2‐gender interaction is a general phenomenon across different populations, is still an open question, the answer to which requires additional, specifically designed, studies.

Loss-of-Function Mutations in APPL1 in Familial Diabetes Mellitus

Diabetes mellitus is a highly heterogeneous disorder encompassing several distinct forms with different clinical manifestations including a wide spectrum of age at onset. Despite many advances, the causal genetic defect remains unknown for many subtypes of the disease, including some of those forms with an apparent Mendelian mode of inheritance. Here we report two loss-of-function mutations (c.1655T>A [p.Leu552(∗)] and c.280G>A [p.Asp94Asn]) in the gene for the Adaptor Protein, Phosphotyrosine Interaction, PH domain, and leucine zipper containing 1 (APPL1) that were identified by means of whole-exome sequencing in two large families with a high prevalence of diabetes not due to mutations in known genes involved in maturity onset diabetes of the young (MODY). APPL1 binds to AKT2, a key molecule in the insulin signaling pathway, thereby enhancing insulin-induced AKT2 activation and downstream signaling leading to insulin action and secretion. Both mutations cause APPL1 loss of function. The p.Leu552(∗) alteration totally abolishes APPL1 protein expression in HepG2 transfected cells and the p.Asp94Asn alteration causes significant reduction in the enhancement of the insulin-stimulated AKT2 and GSK3β phosphorylation that is observed after wild-type APPL1 transfection. These findings-linking APPL1 mutations to familial forms of diabetes-reaffirm the critical role of APPL1 in glucose homeostasis.

Low Prevalence of HNF1A Mutations After Molecular Screening of Multiple MODY Genes in 58 Italian Families Recruited in the Pediatric or Adult Diabetes Clinic From a Single Italian Hospital

Maturity-onset diabetes of the young (MODY; MIM# 606391) is a genetically and clinically heterogeneous form of diabetes, accounting for 1–2% of all diabetes cases (1). MODY is characterized by mild hyperglycemia or overt diabetes usually detected in three consecutive generations, with onset before the age of 25 years and absence of type 1 diabetes autoantibodies. Among the thirteen MODY genes identified, two subtypes, GCK -MODY and HNF1A -MODY, account for most of cases (1). The prevalence of GCK -MODY has been reported higher in Southern Europe (2), while HNF1A -MODY is the most common MODY subtype in Northern Europe (3). This difference might be attributable to the clinical setting in which genetic screening is performed, especially when pediatric and adult diabetes clinics are distinct entities. We addressed this issue by investigating MODY patients identified in the pediatric or in the adult diabetes clinics of the same research-based …

Identification and Clinical Characterization of Adult Patients with Multigenerational Diabetes Mellitus

Background Some patients diagnosed as having type 2 diabetes mellitus (T2DM) are, instead, affected by multigenerational diabetes whose clinical characteristics are mostly undefined. Objective 1. To identify among patients who had been previously defined as affected by T2DM those, in fact, affected by multigenerational diabetes; 2. After excluding patients carrying the most common MODY genes and mitochondrial mutations, we compared clinical features of remaining patients with those of patients with T2DM. Methods Among 2,583 consecutive adult patients who had been defined as affected by T2DM, we looked for those with diabetes in ≥3 consecutive generations. All probands were screened for mutations in six MODY genes (HNF4A, GCK, HNF1A, PDX1, HNF1B and NeuroD1) and for the A3243G mitochondrial mutation. After excluding patients with mutations in one of such genes, we compared clinical features of the remaining 67 patients (2.6% of the whole initial sample) affected by multigenerational “familial diabetes of the adulthood” (FDA) and of their diabetic relatives (n = 63) to those with T2DM (n = 1,028) by generalized hierarchical linear models followed by pairwise comparisons. Results Age, age at diagnosis, proportion of hypertension (all p<0.001), and waist circumference (p<0.05) were lower in FDA than T2DM. Nonetheless, the two groups had similar age-adjusted incidence rate of all-cause mortality. Conclusions Beside younger age at diagnosis, FDA patients show lower waist circumference and reduced proportion of hypertension as compared to those with T2DM; despite such reduced potential cardiovascular risk factors, FDA patients did not show a reduced mortality risk than patients with T2DM.

Insights From Molecular Characterization of Adult Patients of Families With Multigenerational Diabetes

Multigenerational diabetes of adulthood is a mostly overlooked entity, simplistically lumped into the large pool of type 2 diabetes. The general aim of our research in the past few years is to unravel the genetic causes of this form of diabetes. Identifying among families with multigenerational diabetes those who carry mutations in known monogenic diabetes genes is the first step to then allow us to concentrate on remaining pedigrees in which to unravel new diabetes genes. Targeted next-generation sequencing of 27 monogenic diabetes genes was carried out in 55 family probands and identified mutations verified among their relatives by Sanger sequencing. Nine variants (in eight probands) survived our filtering/prioritization strategy. After likelihood of causality assessment by established guidelines, six variants were classified as “pathogenetic/likely pathogenetic” and two as “of uncertain significance.” Combining present results with our previous data on the six genes causing the most common forms of maturity-onset diabetes of the young allows us to infer that 23.6% of families with multigenerational diabetes of adulthood carry mutations in known monogenic diabetes genes. Our findings indicate that the genetic background of hyperglycemia is unrecognized in the vast majority of families with multigenerational diabetes of adulthood. These families now become the object of further research aimed at unraveling new diabetes genes.

ENPP1 mRNA levels in white blood cells and prediction of metformin efficacy in type 2 diabetic patients: a preliminary evidence.

Metformin is the “first choice” oral hypoglycemic agent (OHA) in type 2 diabetes mellitus (T2DM) [1]. The efficacy of metformin varies across individuals [1], supposedly due to environmental and genetic factors. Genetic predictors of metformin efficacy are mostly unknown, with few exceptions [2,3]. Unraveling such predictors would help tailoring metformin treatment. We investigated the role of mRNA levels in white blood cells (WBCs) of ENPP1, an inhibitor of insulinreceptor signaling, in predicting the efficacy of metformin. Sixty-two Italian patients of European ancestry with T2DM (age: 40e70 yrs; disease duration: 2e25 yrs; HbA1c: 6.5e9%; no insulin therapy) were studied. Previous OHA were discontinued for 5 days before adding metformin (2550 mg/ daily). BMI, overnight fasting glucose, insulin, triglycerides, HDL-cholesterol were measured before and after 3-month metformin treatment. ENPP1 mRNA levels were measured by quantitative RT-PCR in WBCs. After metformin treatment, there was an improvement in BMI (32.7 7.2 vs. 31.8 7.1 kg/m, p < 0.0001), fasting glucose (173.0 43.8 vs. 147.1 37.8 mg/dl, p < 0.0001), HOMA-IR (4.0 2.3 vs. 3.2 2.2, p Z 0.002) and HDL-cholesterol (41.2 10.5 vs. 44.1 10.8, p< 0.001). No change in ENPP1 mRNA levels was observed (6.8 5.8 vs. 7.4 5.5 arbitrary units, p Z 0.20). ENPP1 mRNA levels predicted metformin efficacy in reducing fasting glucose (p Z 0.03, r Z 0.07) but not HOMA-IR (p Z 0.82, r Z 0.001). Metformin efficacy was predicted also by gender (women > men) and baseline fasting glucose (the higher baseline glucose level, the higher treatment efficacy), but not age, disease duration, BMI and HOMA-IR. Gender (p < 0.005), fasting glucose (p < 0.001) and ENPP1 mRNA (p < 0.05) remained independent predictors of metformin efficacy in a model comprising also duration of T2DM and BMI (age and HOMA-IR were not tested because of their collinearity with disease duration and fasting glucose). The multivariate r were 0.46 and 0.41 (p Z 0.002) in the model with and without ENPP1. The mechanism through which ENPP1 modulates metformin efficacy might be due to their opposite effect on insulin signaling. Metformin is reported to up-regulate IRS-1 expression viaAMP-activated protein kinase [4] to suppress hyperglycemia-induced IRS-1 deactivation [5] and to exert a positive effect on insulin-receptor number and

Familial diabetes of adulthood: A bin of ignorance that needs to be addressed

AIMS The aim of this article was to share with a wide readership some data and related reasoning about a multigenerational form of diabetes mellitus of adulthood. DATA SYNTHESIS We have recently described a familial form of diabetes mellitus, which in the routine clinical setting of adult individuals is simplistically diagnosed as type 2 diabetes. Such misdiagnosis involves as much as 3% of adult unrelated diabetic patients with no evidence of autoimmune disease. More recent data, obtained by means of a next-generation sequencing, indicate that approximately 25% of such patients carry mutations in the genes involved in monogenic diabetes, thus leaving unraveled the molecular causes of the remaining 75% individuals. CONCLUSIONS Our proposal is to define the latter patients as being affected by familial diabetes of adulthood (FDA), a clear admission of ignorance and a limbo where adult patients with multigenerational diabetes with no genetic definition of their hyperglycemia have to wait for better times.