Use of epidemiologically well-defined subjects and existing immunofluorescence assays to calibrate a new enzyme immunoassay for human herpesvirus 8 antibodies

Agreement between assays for the detection of human herpesvirus 8 (HHV-8) antibodies has been limited. In part, this disagreement has been because assay calibration (i.e., differentiating positive from negative results) has not been done in a standardized fashion with reference to a wide spectrum of HHV-8-infected (true-positive) and HHV-8-uninfected (true-negative) persons. To describe the performance of an assay for HHV-8 antibodies more accurately, we used epidemiologically well-characterized subjects in conjunction with testing on two existing immunofluorescence assays for HHV-8 antibodies to define two groups: a group of 135 HHV-8-infected individuals (true positives), including Kaposi's sarcoma patients and those asymptomatically infected, and a group of 234 individuals with a high likelihood of being HHV-8 uninfected (true negatives). A new enzyme immunoassay (EIA), using lysed HHV-8 virion as the antigen target, was then developed. With the above true positives and true negatives as references, the sensitivity and specificity of the EIA associated with different cutoff values were determined. At the cutoff that maximized both sensitivity and specificity, sensitivity was 94% and specificity was 93%. When the EIA was used to test a separate validation group, a distribution of seropositivity that matched that predicted for the agent of Kaposi's sarcoma was observed: 55% of homosexual men were seropositive, versus 6% seropositivity in a group of children, women, and heterosexual men. It is proposed that the EIA has utility for large-scale use in a number of settings and that the calibration method described can be used for other assays, both to more accurately describe the performance of these assays and to permit more-valid interassay comparison.     

Two polymorphisms in the epithelial cell-derived neutrophil-activating peptide (ENA-78) gene

Increased expression of epithelial cell-derived neutrophil-activating peptide (ENA-78) has been reported in several immune and inflammatory conditions suggesting its role in inflammatory response. We have identified two single nucleotide polymorphisms in the promoter and exon 2 of the ENA-78 gene by scanning the full length gene using DHPLC DNA fragment analysis and DNA sequencing. The polymorphism at position +398 (A/G from the first ATG codon) in exon 2 results in a synonymous substitution not resulting in an amino acid change. The promoter polymorphism was found at position -156 (C/G from the first ATG codon). An assay was designed for the detection of the polymorphisms using SNapshot ddNTP primer extension, followed by capillary electrophoresis (ABI 3100). Allele and genotype frequencies for the promoter -156 polymorphism are presented for 107 healthy Spanish and 54 UK Caucasians. Frequencies for the exon 2 polymorphism are also presented for 63 UK Caucasians.     

Silver nitrate mimicking a foreign body in the pharyngeal mucosal space

Silver nitrate is sometimes used as a means of chemical cauterization for control of minor bleeding and management of hypergranulation tissue following bedside head and neck procedures. There are only few reports available on the imaging appearance of silver nitrate and its potential to mimic a foreign body. We report a case of a patient presenting with dysphagia, odynophagia, and fever following dental work who had a peritonsillar incision and drainage for treatment of a deep neck space infection. During the procedure, silver nitrate was applied to halt the bleeding. Patient was subsequently transferred to another institution. Since the patient was not showing significant clinical improvement on antibiotic therapy, a computed tomography (CT) scan was performed demonstrating a hyperdense structure lodged in the pharyngeal mucosal space in the oropharynx and soft palate that was mistaken for a foreign body such as bone. Silver nitrate can have density similar to bone but does not have the normal architecture of bone with cortex and marrow on CT. Familiarity with the appearance of silver nitrate on CT, lack of bone architecture, and proper documentation and communication of the use of silver nitrate to the consultant radiologist and medical personnel could help avoid misdiagnosis and potentially unnecessary surgical exploration.     

Efficacy of high-energy collimator for sentinel node lymphoscintigraphy of early breast cancer patients

Introduction

Lymphoscintigraphy is an important part of sentinel node mapping in breast cancer patients. Sometimes star shaped artefacts due to septal penetration can be problematic during imaging. In the current study, we evaluated the possibility of high energy (HE) collimators use for lymphoscintigraphy.

Patients and methods

Twenty patients with early breast carcinoma were included. Thirty minutes after radiotracer injection (99mTc-antimony sulphide colloid), anterior and lateral images were acquired using a dual head gamma camera equipped with a parallel hole low energy high resolution (LEHR) collimator on one head and HE collimator on another head. All images were reviewed by two nuclear medicine specialists regarding detectability and number of axillary sentinel nodes and presence of star artefact.

Results

All images taken by LEHR collimators showed star artefact of the injection site. No image taken by HE collimator showed this effect. In two patients the sentinel node was visible only by HE collimator. Tumour location in both of these patients was in the upper lateral quadrant and both had history of excisional biopsy. In two patients additional sentinel node was visible adjacent to the first one only on the LEHR images.

Conclusions

HE collimators can be used for sentinel lymph node mapping and lymphoscintigraphy of the breast cancer patients. This collimator can almost eliminate star-shaped artefacts due to septal penetration which can be advantageous in some cases. However, to separate two adjacent sentinel nodes from each other LEHR collimators perform better.     

Lymphomatoid Granulomatosis with Splenomegaly and Pancytopenia

Lymphomatoid granulomatosis (LG) is an angiocentric lymphoproliferative disease. It usually involves lung, skin, and central nervous system, but splenomegaly and pancytopenia are the rare manifestations of the disease. We report a 15-year-old boy presented with fever, dry cough and dyspnea from two months ago, after admission patient had nodular lesions on the left leg and hepatosplenomegaly. Then he manifested neurologic signs such as seizure, aphasia and right-sided hemiplegia. Chest X-ray and CT scan rev...     

Low serum leptin serves as a biomarker of malnutrition in elderly patients

Anthropometric and classical biologic markers of malnutrition, such as serum albumin, are limited because they are influenced by nonnutritional factors. We propose that a biologic parameter that both predicts nutritional status and is unaffected by nonnutritional factors would facilitate the diagnosis of malnutrition in the elderly. This cross-sectional study included 179 randomized elderly patients. Nutritional status was assessed by the Mini-Nutritional Assessment (MNA) instrument; other end points included anthropometric measures and biologic parameters. Subjects were divided into 3 groups based on MNA-defined nutritional status, and end point means were compared using 2-way analyses of variance adjusted by sex. Correlations between the most accurate biologic marker in predicting malnutrition and other biologic and clinical variables were assessed using Pearson correlation test. Multiple linear regressions were then performed to relate the best biomarker of malnutrition to specific parameters. Finally, leptin levels that predict malnutrition were determined using receiver operating characteristic curve cutoff values. The well-nourished group had significantly higher leptin (P = .001), weight, body mass index, mid-arm circumference, and calf circumference (all, P < .001) compared with the malnourished group and the at risk of malnutrition group. Serum leptin was the optimal biomarker of MNA-defined malnutrition and had significant positive correlations with weight (P = .003) and with all anthropometric values (all P < .001), but no significant correlation with C-reactive protein. Sex, weight, and triglyceride were the best predictors of serum leptin (all P < .001). The optimal cutoff value of serum leptin to detect malnutrition was 4.3 ng/mL in men and 25.7 ng/mL in women. Serum leptin may be a good predictor of nutritional status in elderly patients.