CD44 Splice Variants as Potential Players in Alzheimer's Disease Pathology.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive deficits, deposition of amyloid-ß (Aß) plaques, intracellular neurofibrillary tangles, and neuronal cell death. Neuroinflammation is commonly believed to participate in AD pathogenesis. CD44 is an inflammation-related gene encoding a widely-distributed family of alternatively spliced cell surface glycoproteins that have been implicated in inflammation, metastases, and inflammation-linked neuronal injuries. Here we investigated the expression patterns of CD44S (which does not contain any alternative exon) and CD44 splice variants in postmortem hippocampal samples from AD patients and matched non-AD controls. The expression of CD44S and CD44 splice variants CD44V3, CD44V6, and CD44V10 was significantly higher in AD patients compared to non-AD controls. Immunohistochemistry of human hippocampal sections revealed that CD44S differentially localized to neuritic plaques and astrocytes, whereas CD44V3, CD44V6, and CD44V10 expression was mostly neuronal. Consistent with these findings, we found that the expression of CD44V6 and CD44V10 was induced by Aß peptide in neuroblastoma cells and primary neurons. Furthermore, in loss of function studies we found that both CD44V10-specific siRNA and CD44V10 antibody protected neuronal cells from Aß-induced toxicity, suggesting a causal relationship between CD44V10 and neuronal cell death. These data indicate that certain CD44 splice variants contribute to AD pathology and that CD44V10 inhibition may serve as a new neuroprotective treatment strategy for this disease.

Genetic considerations in human sex-mate selection: partners share human leukocyte antigen but not short-tandem-repeat identity markers.

PROBLEM: Previous studies support a role for MHC on mating preference, yet it remains unsettled as to whether mating occurs preferentially between individuals sharing human leukocyte antigen (HLA) determinants or not. Investigating sex-mate preferences in the contemporary Israeli population is of further curiosity being a population with distinct genetic characteristics, where multifaceted cultural considerations influence mate selection. METHOD OF STUDY: Pairs of male-female sex partners were evaluated in three groups. Two groups represented unmarried (n = 1002) or married (n = 308) couples and a control group of fictitious male-female couples. HLA and short-tandem-repeat (STR) genetic identification markers were assessed for the frequency of shared antigens and alleles. RESULTS: Human leukocyte antigen results showed that Class I and/ or Class II single antigen as well as double antigen sharing was more common in sex partners than in control group couples (P < 0.001). Married versus unmarried pairs were not distinguishable. In contrast, STR-DNA markers failed to differentiate between sex-mates and controls (P = 0.78). CONCLUSION: Sex partnerships shared HLA determinants more frequently than randomly constituted male-female pairs. The observed phenomenon does not reflect a syngenetic background between sex-mates as STR markers were not selectively shared. Thus, sex-mate selection in man may contravene the evolutionary pressure for genetic diversity in regard to HLA.

Screening for cervical neoplasia: a community-based trial comparing Pap staining, human papilloma virus testing, and the new bi-functional Celldetect® stain.

Although cytological screening for cervical neoplasia has lowered mortality rates, current screening methods are plagued by sub-optimal sensitivity and/or specificity. The purpose of this study was to compare the performance of the new CellDetect® staining technology as a potential screening tool. This initial, non-blinded study, utilized samples are taken at a community-based clinic. The diagnostic results using CellDetect® were compared with the performance of Pap staining and human papilloma virus (HPV) testing on the same material, as well as the follow-up biopsies. These data were statistically analyzed in terms of sensitivity, specificity, predictive value (N.P.V and P.P.V), and inter-observer agreement. Bi-functional CellDetect® staining revealed morphological details and tinctorial properties that permitted recognition of neoplasia even at low magnification. Performance-wise, CellDetect® demonstrated non-inferiority for all statistical parameters to both Pap and HPV tests. Importantly, superior sensitivity compared with Pap staining was observed, as well as higher specificity than HPV testing with near equivalent sensitivity. We conclude that CellDetect® is a promising approach to early detection of cervical cancer because of its bi-functional capabilities that afford high sensitivity and specificity. The data suggest that this new methodology warrants further and more extensive clinical evaluation.

Novel dual-function CellDetect® staining technology: wedding morphology and tinctorial discrimination to detect cervical neoplasia.

BACKGROUND: A persistent goal of oncologic histochemistry is to microscopically identify neoplasia tinctorially. Consequently, the newly developed CellDetect® staining technology, that appears to exhibit this property, warrants clinical evaluation. The objective of this study was to compare the diagnostic results using CellDetect® to the outcomes of standard microscopic examination based on hematoxylin and eosin (H&E) staining for the recognition of different squamous epithelial phenotypes of the uterine cervix. METHODS: Pairs of adjacent sections were made from 60 cervical biopsy cases that were diagnosed originally as either normal or neoplastic (CIN, SCC). One section of the pair was stained for H&E; the second section, with CellDetect®. Based on the examination of these pairs by two experienced pathologists, we investigated the following issues:(1) diagnostic agreement between the pathologists on each pair; (2) agreement between H&E and CellDetect® for each pair (3) tinctorial characteristics in micro-regions (n = 130) evaluated as either normal, reactive or neoplastic. RESULTS: Qualitatively, CellDetect®-stained preparations displayed cyto-morphological detail comparable to H&E images. Tinctorially, non-neoplastic cells appeared green/blue when stained withCellDetect®, contrasting with cytologically neoplastic foci, where cells of every grade were red/magenta in color. Due to these tinctorial characteristics, even small foci of neoplasia could be readily distinguished that were inconspicuous on H&E at low magnification. In some instances, this prompted re-examination of the H&E and revision of the diagnosis. Quantitatively, we found that despite diagnostic variation between pathologists, in about 3% of the cases, each pathologist made the same diagnosis regardless of whether CellDetect® or H&E was used, i.e. there was 100% self-agreement for each pathologist between stains. Particularly noteworthy was the finding of a 0% false negative rate, coupled with a 10-15% false positive rate. Regarding specificity, the performance in reactive squamous processes was similar to that observed for morphologically normal squamous epithelium. CONCLUSIONS: In this first order assessment of clinical applicability, CellDetect® staining technology was at least comparable to results using H&E, and perhaps surperior. CellDetect® provided a uniquely useful tinctorial clue for the detection of neoplasia, which exhibited an impressive 0% false negative rate. A more extensive, blinded study is needed to confirm these promising findings.

Individualized immune monitoring of cardiac transplant recipients by noninvasive longitudinal cellular immunity tests.

BACKGROUND: Common immunosuppression strategies after heart transplantation (HTx) are based on accepted target drug levels, disregarding that drug levels do not correlate with the individual patient's pharmacokinetics or with the actual immunosuppressive drug effect on the patient. The Immuknow assay is used for immune monitoring and management of organ transplant recipients. This study evaluated the Immuknow assay for longitudinal immune monitoring of HTx patients throughout various clinical settings. METHODS: The functional immune response as measured by the Immuknow assay was determined in 327 samples collected from 50 HTx patients at the Rabin Medical Center and was analyzed together with common clinical parameters. RESULTS: The median Immuknow levels measured throughout the infection episodes and the episodes of biopsy-proven acute rejection were 129 and 619 ng ATP/mL, respectively. These values were significantly dissimilar to the median Immuknow level measured during clinical quiescence, which was 351 ng ATP/mL (P<0.05). Calcineurin inhibitors drug-level measurements did not provide a reliable depiction of the patients' immune function, because the median deviation from the recommended drug trough levels range was significantly higher than the median deviation of Immuknow levels from their expected immune response zones. Longitudinal monitoring of Immuknow levels through serial testing proved to be a reliable method for individual patient immune management. CONCLUSIONS: The Immuknow assay reliably reflects the cellular immune function of HTx patients, thereby supporting the immune monitoring and management of these patients. Serial longitudinal Immuknow monitoring allows immune management of therapy according to the individual patient's immune status.

Successful cell-mediated cytokine-activated immunotherapy for relapsed acute myeloid leukemia after hematopoietic stem cell transplantation.

Acute myeloid leukemia (AML) is an extremely aggressive disease with a high relapse rate even after allogeneic hematopoietic stem cell transplantation (HSCT). We report the successful outcome of cell-mediated cytokine-activated immunotherapy in a high-risk pediatric AML patient who relapsed shortly after allogeneic HSCT. Donor lymphocyte infusion along with interferon induced a graft-versus-leukemia effect, presenting as a reversible episode of graft-versus-host disease, which led to stable complete donor chimerism and total eradication of AML for over 24 months, at the time of this report. The curative potential of immunotherapy in hematological malignancies is discussed.

Frontiers of stem cell transplantation monitoring: capturing graft dynamics through routine longitudinal chimerism analysis.

Quantitative chimerism testing has become an indispensable tool for following the course and success of allogeneic hematopoietic stem cell transplants. In this paper, we describe the current laboratory approach to quantitative chimerism testing based on an analysis of short tandem repeats, and explain why performing this analysis longitudinally is important and feasible. Longitudinal analysis focuses on relative changes appearing in the course of sequential samples, and as such exploits the ultimate potential of this intrinsically semi-quantitative platform. Such an analysis is more informative than single static values, less likely to be confused with platform artifacts, and is individualized to the particular patient. It is particularly useful with non-myeloablative conditioning, where mixed chimerism is common. When longitudinal chimerism analysis is performed on lineage-specific subpopulations, the sensitivity, specificity and mechanistic implications of the data are augmented. Importantly, longitudinal monitoring is a routinely feasible laboratory option because multiplex STR-PCR kits are available commercially, and modern software can be used to perform computation, reliability testing, and longitudinal tracking in a rapid, easy to use format. The ChimerTrack application, a shareware program developed in our laboratory for this purpose, produces a report that automatically summarizes and illustrates the quantitative temporal course of the patient's chimeric status. Such a longitudinal perspective enhances the value of quantitative chimerism monitoring for decisions regarding immunomodulatory post-transplant therapy. This information also provides unique insights into the biological dynamics of engraftment underlying the fluctuations in the temporal course of a patient's chimeric status.

Hematopoietic chimerism monitoring based on STRs: quantitative platform performance on sequential samples.

Hematopoietic stem cell transplantation (HSCT) creates a donor-recipient cellular chimerism in the patient, which is quantitatively assayed from peripheral blood based on STR-DNA. Since chimerism values often vary across a patient's samples, it is important to determine to what extent this variability reflects technical aspects of platform performance. This issue is systematically assessed in the current study for the first time. Using the SGM Plus multiplex PCR kit and ABI platform, the longitudinal performance of STR markers was quantitatively evaluated in two chimeric models with true values, and in patient samples (n >500 marker loci). Computation of percent chimerism for each marker, and mean (sample) percent chimerism, standard deviation, and coefficient of variance was performed by our ChimerTrack utility. In chimeric models with known values, individual markers exhibited an accuracy (observed/true) of 88-98%; replication precision was 92-100% true, with a mean error of 2%. Fragment size calling was greater than 99% accurate and precise. Patient results were comparable for markers, relaive to sample means. One source of technical variability in chimerism estimation was allelic differential amplification efficiency. The latter was influenced by signal amplitude, dye label, marker size, and allelic size interval. It can be concluded that long-term chimeric tracking is routinely feasible using this platform in conjunction with ChimerTrack software. Importantly, mean percent chimerism, for any sample, should closely approximate the true chimeric status, with a technical accuracy of 98%. Guidelines are presented for selecting an optimized marker profile.

The spectrum of laryngeal neoplasia: the pathologist's view.

Several types of neoplastic change with different prognostic implications typically involve the laryngeal squamous epithelium. The purpose of this review is to examine the spectrum of these changes, as well as their relationship to benign squamous epithelial proliferative states. Since these pathological changes are apt to occur in regions where the epithelial lining is typically squamous, it is important to recognize that the epithelium of the larynx varies from stratified squamous to respiratory-type, depending on the location. The lingual (anterior) surface of the epiglottis is lined by a stratified squamous type, while the laryngeal (posterior) surface is stratified squamous merging into respiratory-type. In the larynx, the supraglottic and infraglottic portions are a respiratory-type, which contrasts with the stratified squamous epithelium of the glottis. This typical distribution does show some degree of variability in those patches of squamous epithelium and is frequently seen within the respiratory-type epithelial regions. The junction between the two epithelial types may be abrupt or separated by a transitional zone.