Droplet Digital PCR Detects Low-Density Infection in a Significant Proportion of Helicobacter Pylori-Negative Gastric Biopsies of Dyspeptic Patients.

INTRODUCTION: Helicobacter pylori-infected individuals may present low-density infection, undetectable by conventional tests such as histology, rapid urease test, or urea breath test. Droplet digital polymerase chain reaction (ddPCR) is more sensitive than other polymerase chain reaction methods. We aimed to evaluate the ability of ddPCR to detect H. pylori infection in patients diagnosed as negative by conventional tests. METHODS: Dyspeptic patients (n = 236) were tested for H. pylori by histology, urea breath test, and rapid urease test. Patients were classified as having 3 positive (n = 25, control group), 2 positive (n = 12), one positive (n = 41), or zero positive (n = 158) diagnostic tests. DNA was extracted from gastric biopsies. Triplicate ddPCR testing for each of the 16S rDNA, ureA, and vacA(s) genes was performed using a QX200 ddPCR system (Bio-Rad). A gene was considered positive when detected by at least 2 of 3 repeated ddPCRs. H. pylori positivity was defined as having 2 or more positive genes. RESULTS: All the biopsies of the control patients were positive for all 3 16S rDNA, ureA, and vacA(s) genes. H. pylori infection was detected in 57 (36%), 22 (54%), and 9 (75%) patients with zero, 1, and 2 positive diagnostic tests, respectively. The density of infection was 5, 121, 599, and 3,133 copies of H. pylori genome equivalents for patients with zero, 1, and 2 of 3 positive test results and for the control group, respectively. DISCUSSION: ddPCR detected low-density "occult" H. pylori infection in a significant proportion (36%) of patients diagnosed as negative by conventional methods. The number of conventional positive tests was related to the density of infection.

Utility of histology for the diagnosis of portal hypertensive gastroenteropathy. Concordance between the endoscopic image and gastrointestinal biopsies. Role of the CD34 marker. / Utilidad de la histología para el diagnóstico de la gastroenteropatía por hipertensión portal. Concordancia entre la imagen endoscópica y las biopsias gastrointestinales. Papel del marcador CD34.

INTRODUCTION: Upper gastroscopy in patients with cirrhosis often reveals non-specific lesions, which are usually oriented as portal hypertensive gastropathy (PHG). However, the diagnosis of PHG can be difficult, both from an endoscopic and histological point of view. The study of CD34 expression, which enhances the endothelial cells of the microvasculature, could help the differential diagnosis. The objectives of this study were to evaluate the correlation between endoscopy and histology in the diagnosis of PHG and to assess the utility of CD34 in the diagnosis of PHG. MATERIAL AND METHODS: The results of immunostaining with CD34 gastric fundus biopsies from 100 cirrhotic patients and 20 controls were compared with the endoscopic images. RESULTS: The correlation between the histology and the endoscopic diagnosis of PHG was very low (kappa=0.15). In addition, the measurement of the diameter of the gastric vessels enhanced by the use of immunohistochemical staining (CD34) did not show good correlation with the endoscopic diagnosis (p=.26) and did not provide relevant information for the histological diagnosis of PHG either. DISCUSSION: The correlation between histology and endoscopy is low for the diagnosis of PHG. The use of immunostaining for CD34 does not seem to improve the diagnostic yield of the histological study.

Human Subcutaneous Tissue Response to Glucose Sensors: Macrophages Accumulation Impact on Sensor Accuracy.

BACKGROUND: Subcutaneous (s.c.) glucose sensors have become a key component in type 1 diabetes management. However, their usability is limited by the impact of foreign body response (FBR) on their duration, reliability, and accuracy. Our study gives the first description of human acute and subacute s.c. response to glucose sensors, showing the changes observed in the sensor surface, the inflammatory cells involved in the FBR and their relationship with sensor performance. METHODS: Twelve obese patients (seven type 2 diabetes) underwent two abdominal biopsies comprising the surrounding area where they had worn two glucose sensors: the first one inserted 7 days before and the second one 24 h before biopsy procedure. Samples were processed and studied to describe tissue changes by two independent pathologists (blind regarding sensor duration). Macrophages quantification was studied by immunohistochemistry methods in the area surrounding the sensor (CD68, CD163). Sensor surface changes were studied by scanning electron microscopy. Seven-day continuous glucose monitoring records were considered inaccurate when mean absolute relative difference was higher than 10%. RESULTS: Pathologists were able to correctly classify all the biopsies regarding sensor duration. Acute response (24 h) was characterized by the presence of neutrophils while macrophages were the main cell involved in subacute inflammation. The number of macrophages around the insertion hole was higher for less accurate sensors compared with those performing more accurately (32.6 ± 14 vs. 10.6 ± 1 cells/0.01 mm2; P < 0.05). CONCLUSION: The accumulation of macrophages at the sensor-tissue interface is related with decrease in accuracy of the glucose measure.

APLP2, RRM2, and PRC1: New Putative Markers for the Differential Diagnosis of Thyroid Follicular Lesions.

BACKGROUND: Current methods based on fine-needle aspiration biopsy (FNAB) are not sufficient to distinguish among follicular thyroid lesions, follicular adenoma (FA), follicular thyroid carcinoma (FTC), and the follicular variant of papillary thyroid cancer (FVPTC). Furthermore, none of the immunohistochemical markers currently available are sensitive or specific enough to be used in the clinical setting, necessitating a diagnostic hemithyroidectomy. The aim of this study was to identify proteins of value for differential diagnosis between benign and malignant thyroid follicular lesions. METHODS: This retrospective analysis is based on an assessment of the immunoexpression of 19 proteins on 81 benign thyroid lesions (FA) and 50 malignant tumors (FTC/FVPTC). The resulting expression profile allowed the design of a scoring system model to improve the differential diagnosis of benign and malignant thyroid lesions. The model was validated using an independent series of 69 FA and 40 FTC and an external series of 40 nodular hyperplasias, and was further tested in a series of 38 FNAB cell blocks. RESULTS: A model based on the nuclear and cytoplasmic expression of APLP2, RRM2, and PRC1 discriminated between benign and malignant lesions with 100% sensitivity in both main and validation groups, with specificities of 71.3% and 50.7%, respectively. For the nodular hyperplasia series, specificity reached 94.8%. Finally, in FNAB samples, the sensitivity was 100% and the specificity was 45% for discrimination between benign and malignant lesions. CONCLUSIONS: These findings suggest that the identified APLP2, RRM2, and PRC1 signature could be useful for distinguishing between benign (FA) and malignant (FTC and FVPTC) tumors of the thyroid follicular epithelium.

Usefulness of indirect noninvasive methods in predicting progression to cirrhosis in chronic hepatitis C.

BACKGROUND AND AIMS: The ability of noninvasive methods to predict the development of cirrhosis has not been established. We evaluated the ability of three noninvasive methods [the Forns index, the aspartate aminotransferase-to-platelet ratio index (APRI), and the Non-Invasive Hepatitis-C-related Cirrhosis Early Detection (NIHCED) score] to determine the risk of developing cirrhosis in chronic hepatitis C. METHODS: Consecutive patients with chronic hepatitis C who had undergone liver biopsy between 1998 and 2004 were eligible. We used the three methods to evaluate patients at baseline and at follow-up (4-10 years later). When these methods yielded discordant or indeterminate results, a second liver biopsy was performed. Logistic regression models were fitted for each method to predict whether cirrhosis would appear and to predict long-term mortality from cirrhosis. RESULTS: We included 289 patients in our study. The mean scores at baseline and at follow-up, respectively, were as follows: Forns, 5.47 ± 1.95 and 6.56 ± 2.02; APRI, 1.1 ± 2.33 and 1.4 ± 1.53; and NIHCED, 7.79 ± 11.45 and 15.48 ± 15.28. The area under the receiver operating characteristic curve for predicting cirrhosis was 0.83 for Forns, 0.79 for APRI, and 0.76 for NIHCED. The sensitivity and specificity for predicting cirrhosis, respectively, were 75 and 71% for Forns (cutoff 4.7), 86 and 42% for APRI (cutoff 0.48), and 41 and 82% for NIHCED (cutoff 0). The area under the receiver operating characteristic curve for predicting mortality was 0.86 for Forns, 0.79 for APRI, and 0.84 for NIHCED. CONCLUSION: Indirect noninvasive markers could help identify patients with chronic hepatitis C at risk of progression to cirrhosis.

A descriptive study of the characteristics of differentiated thyroid cancer in Catalonia during the period 1998-2012. The CECaT registry.

INTRODUCTION: The consortium for the study of thyroid cancer (CECaT), including 20 hospitals and one research institute, was recently created in Catalonia (Spain). One of the first initiatives of the group was to perform a descriptive analysis of the characteristics of patients with differentiated thyroid carcinoma (DTC). PATIENTS AND METHODS: The cohort included 1,855 patients from 11 hospitals treated over a period of 15 years (1998-2012). RESULTS: In this series, 1.470 (79.2%) patients were women. Mean age was 47.7 (15.7) years old. Age was significantly higher in male than in female patients, 49.3 (15) versus 47.3 (15.8); p=0.02. Papillary thyroid carcinoma accounted for 88.9% of cases. Mean tumor size was 21.5 (16) mm, and was significantly lower in females than in males, 20.1 (14.5) mm and 26.6 (20.3) mm respectively (p<0.001). After a follow-up period of 5.5 (3.7) years, information was available for 1,355 patient, of whom 1065 (78.6%) were free of disease, 239 (17.6%) had no tumor persistence, and 51 (3.8) % had died. The risk of persistent or recurrent disease was significantly associated to older age at diagnosis, male gender, larger tumor size, lymph node metastases at surgery, no signs of thyroiditis in the remaining thyroid tissue, and presence of vascular and/or extraglandular invasion. CONCLUSIONS: Patient characteristics analyzed are similar to those reported in other parts of the world.

[Gastric vascular lesions in cirrhosis: gastropathy and antral vascular ectasia]. / Lesiones vasculares gástricas en la cirrosis: gastropatía y ectasia vascular antral.

Portal hypertensive gastropathy (GHP) is a complication of portal hypertension usually associated with liver cirrhosis. The pathogenesis is unclear but the presence of portal hypertension is an essential factor for its development. GHP may be asymptomatic or present as gastrointestinal bleeding or iron deficiency anemia. Endoscopic lesions vary from a mosaic pattern to diffuse red spots; the most common location is the fundus. Treatment is indicated when there is acute or chronic bleeding, as secondary prophylaxis. There is insufficient evidence to recommend primary prophylaxis in patients who have never bled. Drugs that decrease portal pressure, such as non-cardioselective beta-blockers, and/or endoscopic ablative treatments, such as argon-beam coagulation, may be used. The role of transarterial intrahepatic portosystemic shunt) or bypass surgery has been insufficiently analyzed. Antral vascular ectasia (EVA) is a rare entity in liver cirrhosis, whose pathophysiology is still unknown. Clinical presentation is similar to that of GHP and endoscopy usually shows red spots in the antrum. Biopsy is often required to differentiate EVA from GHP. There is no effective medical therapy, so endoscopic ablative therapy and, in severe cases, antrectomy are recommended.

Response to initial therapy of differentiated thyroid cancer predicts the long-term outcome better than classical risk stratification systems.

Objective. Although differentiated thyroid cancer (DTC) usually has an indolent course, some cases show a poor prognosis; therefore, risk stratification is required. The objective of this study is to compare the predictive ability of classical risk stratification systems proposed by the European Thyroid Association (ETA) and American Thyroid Association (ATA) with the system proposed by Tuttle et al. in 2010, based on the response to initial therapy (RIT). Methods. We retrospectively reviewed 176 cases of DTC with a median follow-up period of 7.0 years. Each patient was stratified using ETA, ATA, and RIT systems. Negative predictive value (NPV) and positive predictive value (PPV) were determined. The area under receiver operating characteristic (ROC) curve was calculated in order to compare the predictive ability. Results. RIT showed a NPV of 97.7%, better than NPV of ETA and ATA systems (93.9% and 94.9%, resp.). ETA and ATA systems showed poor PPV (40.3% and 41%, resp.), while RIT showed a PPV of 70.8%. The area under ROC curve was 0.7535 for ETA, 0.7876 for ATA, and 0.9112 for RIT, showing statistical significant differences (P < 0.05). Conclusions. RIT predicts the long-term outcome of DTC better than ETA/ATA systems, becoming a useful system to adapt management strategies.

DNA methylation profiling of well-differentiated thyroid cancer uncovers markers of recurrence free survival.

Thyroid cancer is a heterogeneous disease with several subtypes characterized by cytological, histological and genetic alterations, but the involvement of epigenetics is not well understood. Here, we investigated the role of aberrant DNA methylation in the development of well-differentiated thyroid tumors. We performed genome-wide DNA methylation profiling in the largest well-differentiated thyroid tumor series reported to date, comprising 83 primary tumors as well as 8 samples of adjacent normal tissue. The epigenetic profiles were closely related to not only tumor histology but also the underlying driver mutation; we found that follicular tumors had higher levels of methylation, which seemed to accumulate in a progressive manner along the tumorigenic process from adenomas to carcinomas. Furthermore, tumors harboring a BRAF or RAS mutation had a larger number of hypo- or hypermethylation events, respectively. The aberrant methylation of several candidate genes potentially related to thyroid carcinogenesis was validated in an independent series of 52 samples. Furthermore, through the integration of methylation and transcriptional expression data, we identified genes whose expression is associated with the methylation status of their promoters. Finally, by integrating clinical follow-up information with methylation levels we propose etoposide-induced 2.4 and Wilms tumor 1 as novel prognostic markers related to recurrence-free survival. This comprehensive study provides insights into the role of DNA methylation in well-differentiated thyroid cancer development and identifies novel markers associated with recurrence-free survival.

[Rapid progression of hepatocellular carcinoma after surgery: apropos of a case and review of the literature]. / Rápida progresión de hepatocarcinoma tras cirugía; a propósito de un caso y revisión de la literatura.

We report the case of a young man with chronic hepatitis B infection of probable perinatal acquisition who was diagnosed with hepatocellular carcinoma at a very early stage (BCLC 0) with a highly favorable prognosis. However, the tumor progressed rapidly and the patient died within months. Currently, there are few data that could help to identify cases likely to show rapid progression and which could prompt initiation of aggressive therapies that might prevent or control such progression.

Recurrent stroke as a manifestation of primary angiitis of the central nervous system in a patient infected with human immunodeficiency virus.

CONTEXT: Cerebral vasculitis in patients infected with human immunodeficiency virus (HIV) is usually related to additional or secondary infectious agents other than neoplastic diseases or HIV itself. OBJECTIVE: To describe a 31-year-old patient infected with HIV who presented with 2 recurrent, acute episodes of neurologic impairment in a 5-month period. DESIGN: Comparison of clinical and histologic data between the present case and previously published cases. SETTING: Community hospital. PATIENT: A 31-year-old, HIV-infected patient with recurrent strokes and chronic lymphocytic meningitis. INTERVENTION: After ruling out cardiac embolisms and coagulation disorders, the presence of central nervous system vasculitis, probably secondary to an infectious process, was suspected based on the clinical examination and cerebrospinal fluid abnormalities. RESULTS: Necropsy findings suggest the diagnosis of primary angiitis of the central nervous system, and the only infectious agent that could be found was HIV. CONCLUSIONS: Histologic studies were compatible with a diagnosis of primary angiitis of the central nervous system, but the pathogenic role of HIV in the genesis of the vasculitic process cannot be elucidated.