New pathological insights into cardiac amyloidosis: implications for non-invasive diagnosis.

BACKGROUND: Knowledge of the patterns of myocardial amyloid accumulation could improve the interpretation of electrocardiographic, echocardiographic and magnetic resonance imaging findings of amyloidosis. We assessed the extent and pattern of myocardial amyloid infiltration in explanted or autopsied hearts of patients with cardiomyopathy related to acquired monoclonal immunoglobulin light-chain (AL) or hereditary transthyretin (TTR) related amyloidosis (ATTR). METHODS: We analyzed nine explanted/autopsied hearts from patients with AL (n = 4) and ATTR (n = 5) cardiac amyloidosis. For each heart, a biventricular histological macrosection was obtained at mid-ventricular level and analyzed with both inspective and computer-assisted histologic and histomorphometric analysis aimed in particular at quantifying muscle cells, fibrosis and amyloid infiltration. RESULTS: The extent of amyloid infiltration of the left ventricle (LV) ranged from 45 to 76% (median [interquartile range (IQR)] = 57% [51-64]) of the overall surface. Although LV trabecular and subendocardial were the most infiltrated layers (45-94%, median [IQR] = 73% [67-84] and from 44 to 71%, median [IQR] = 57% [49-59], respectively), intra- and inter-patient heterogeneity was high. Three main patterns of amyloid infiltration of the LV were identified: diffuse (five cases), mainly subendocardial (two cases), and mainly segmental (two cases). The extent of amyloid infiltration of the right ventricle ranged from 48 to 93% (median [IQR] = 61% [59-83]); contributions of parietal and trabecular layers ranged from 32 to 99% (median [IQR] = 63% [47-88]) and from 49 to 93% (median [IQR] = 74% [64-79]), respectively. CONCLUSIONS: In amyloidotic cardiomyopathy, amyloid deposition is highly heterogeneous. Different patterns of infiltration are identifiable, including diffuse, mainly segmental and mainly subendocardial. Awareness of this variability can help the interpretation of ECGs, echocardiograms and magnetic resonance imaging.

Validity of internal expression of the major histocompatibility complex class I in the diagnosis of inflammatory myopathies.

OBJECTIVE: The inflammatory myopathies (IMs) are a group of disorders characterised by weakness and inflammation of the skeletal muscles. Muscle biopsy is the most crucial test to confirm the clinical diagnosis, but also the most common cause of misdiagnosis. There are currently no markers specific or sensitive enough to distinguish IMs from other diseases with similar clinical and morphological features, and an international multidisciplinary effort is under way to develop new classification criteria for IMs. METHODS: Standards for Reporting of Diagnostic Accuracy recommendations to validate a diagnostic test based on the quantification of internal major histocompatibility complex class I (MHC-I) positive fibres were adopted. MHC-I immunostained specimens from 64 patients were scored by two independent blinded investigators, and the percentage of positive fibres was determined. Agreement between investigators was evaluated with the k-weighted statistic. The receiver operating characteristic curve, area under the curve, sensitivity, specificity, and positive and negative predictive values of each percentage range of positive fibres versus the diagnosis of IM were calculated. RESULTS: The main difference between IM and non-inflammatory samples was the number of internal MHC-I positive fibres. The k-weighted value was 0.89 for a percentage of MHC-I positive fibres above 50%; the positive predictive value was 100%, and the negative predictive value was 94%. CONCLUSIONS: This is the first study on the validity of a quantitative analysis of internal MHC-I positive fibres for an IM diagnosis performed according to Standards for Reporting of Diagnostic Accuracy recommendations. The interobserver agreement was almost perfect, thus making the method reproducible. Applying an MHC-I cut-off above 50% is an optimal marker for polymyositis (PM) and dermatomyositis (DM) diagnosis.

Effect of long-term testosterone administration on the endometrium of female-to-male (FtM) transsexuals.

INTRODUCTION: Long term safety of testosterone (T) administration in women is still unknown. In particular few and discordant data exists on the effects of T on the endometrium. AIM: The aim of this study was to investigate the effects of long-term T treatment on endometrium histology and proliferation in female to male transsexual subjects (FtM). We compared these endometria with those of young women in the proliferative phase (PM) of the cycle and with those of post menopausal women (M). METHOD: Endometrial samples from 27 FtM treated with T (intramuscular injection of 100 mg Testoviron Depot /10 days for at least one year), 30 M undergoing vaginal hysterectomy, and 13 PM undergoing hysteroscopy for infertility problems were collected. Endometrial proliferation was evaluated on the basis of histopathology and expression of the proliferation marker Ki-67. Both M and PM women had not received any hormonal treatment for at least one year. MAIN OUTCOME MEASURE: Circulating total testosterone (TT), estradiol (E), progesterone (P), insulin and glucose levels were measured in FtM and PM subjects. RESULTS: FtM had received T for 33.6 +/- 21.3 months (mean +/- SD). In FtM subjects, histological analysis found inactive endometrium similar to the atrophic menopausal endometrium. The expression of Ki-67 in the glands, stroma and glands and stroma together was significantly (p < 0.0005) lower in FtM than in PM women and was similar in the FtM and M groups. Small polyps were detected in 5 of the 27 FtM subjects. CONCLUSIONS: In conclusion our data suggest that exogenous T administration does not stimulate endometrial proliferation in FtM transsexuals and indeed may have atrophic effects.