CD44 variant isoforms control experimental autoimmune encephalomyelitis by affecting the lifespan of the pathogenic T cells.

CD44 variant (CD44(v)) isoforms play important roles in the development of autoimmune disorders, including colitis and arthritis, but their role in multiple sclerosis (MS) has been explored only to a limited extent. We determined the functional relevance of CD44(v) isoforms in MS and its animal model, experimental autoimmune encephalomyelitis (EAE). Genetic ablation of CD44(v7) and CD44(v10) isoforms significantly reduced the clinical EAE burden, as well as the number of inflammatory infiltrates. CD44(v7) and CD44(v10) expression on both memory T and antigen-presenting cells, participated in the development of adoptive transfer EAE. Significantly reduced mRNA expression of Th1 signature genes was detected in the brains of CD44(v10-/-) mice compared with those of CD44(WT) mice. Furthermore, forkhead transcription factor 3 (Foxp3), Bcl-2, and inducible nitric oxide synthase (iNOS) levels were reduced in CD44(v10-/-) brains, whereas active caspase-3 was elevated. Brain-infiltrating CD4(hi)CD44(v10+) T cells preceded EAE onset and paralleled disease severity in wild-type but not in CD44(v7-/-) and CD44(v10-/-) mice. CD44(v7) and CD44(v10) expression contributed to EAE by increasing the longevity of autoreactive CD4(hi)panCD44(hi) T cells. Accordingly, the absence of CD44(v7) and CD44(v10) led to increased apoptosis in the inflammatory infiltrates and reduced Th1 responses, resulting in marked disease reduction. Although absent in noninflamed human brains, we detected CD44(v3), CD44(v7), and CD44(v10) isoforms on glial cells and on perivascular infiltrating cells of MS lesions. We conclude that CD44(v7) and CD44(v10), expressed on autoreactive CD4(hi)panCD44(hi) T cells, are critically involved in the pathogenesis of classic EAE by increasing their life span. Targeting these short CD44(v) isoform regions may reduce inflammatory processes and clinical symptoms in MS.

Making cytological diagnoses on digital images using the iPath network.

BACKGROUND: The iPath telemedicine platform Basel is mainly used for histological and cytological consultations, but also serves as a valuable learning tool. AIM: To study the level of accuracy in making diagnoses based on still images achieved by experienced cytopathologists, to identify limiting factors, and to provide a cytological image series as a learning set. METHOD: Images from 167 consecutive cytological specimens of different origin were uploaded on the iPath platform and evaluated by four cytopathologists. Only wet-fixed and well-stained specimens were used. The consultants made specific diagnoses and categorized each as benign, suspicious or malignant. RESULTS: For all consultants, specificity and sensitivity regarding categorized diagnoses were 83-92 and 85-93%, respectively; the overall accuracy was 88-90%. The interobserver agreement was substantial (κ = 0.791). The lowest rate of concordance was achieved in urine and bladder washings and in the identification of benign lesions. CONCLUSION: Using a digital image set for diagnostic purposes implies that even under optimal conditions the accuracy rate will not exceed to 80-90%, mainly because of lacking supportive immunocytochemical or molecular tests. This limitation does not disqualify digital images for teleconsulting or as a learning aid. The series of images used for the study are open to the public at http://pathorama.wordpress.com/extragenital-cytology-2013/.

Loss of angiomiR-126 and 130a in angiogenic early outgrowth cells from patients with chronic heart failure: role for impaired in vivo neovascularization and cardiac repair capacity.

BACKGROUND: MicroRNAs are key regulators of angiogenic processes. Administration of angiogenic early outgrowth cells (EOCs) or CD34(+) cells has been suggested to improve cardiac function after ischemic injury, in particular by promoting neovascularization. The present study therefore examines regulation of angiomiRs, microRNAs involved in angiogenesis, in angiogenic EOCs and circulating CD34(+) cells from patients with chronic heart failure (CHF) and the role for their cardiac repair capacity. METHODS AND RESULTS: Angiogenic EOCs and CD34(+) cells were isolated from patients with CHF caused by ischemic cardiomyopathy (n=45) and healthy subjects (n=35). In flow cytometry analyses, angiogenic EOCs were largely myeloid and positive for alternatively activated M2 macrophage markers. In vivo cardiac neovascularization and functional repair capacity were examined after transplantation into nude mice with myocardial infarction. Cardiac transplantation of angiogenic EOCs from healthy subjects markedly increased neovascularization and improved cardiac function, whereas no such effect was observed after transplantation of angiogenic EOCs from patients with CHF. Real-time polymerase chain reaction analysis of 14 candidate angiomiRs, expressed in angiogenic EOCs, revealed a pronounced loss of angiomiR-126 and -130a in angiogenic EOCs from patients with CHF that was also observed in circulating CD34(+) cells. Anti-miR-126 transfection markedly impaired the capacity of angiogenic EOCs from healthy subjects to improve cardiac function. miR-126 mimic transfection increased the capacity of angiogenic EOCs from patients with CHF to improve cardiac neovascularization and function. CONCLUSIONS: The present study reveals a loss of angiomiR-126 and -130a in angiogenic EOCs and circulating CD34(+) cells from patients with CHF. Reduced miR-126 expression was identified as a novel mechanism limiting their capacity to improve cardiac neovascularization and function that can be targeted by miR-126 mimic transfection.

Cytokeratin expression in hematological neoplasms: a tissue microarray study on 866 lymphoma and leukemia cases.

Aberrant expression of cytokeratins (CK) is known to occasionally occur in malignant lymphomas. The monoclonal mouse-anti-human CK cocktail CK22 recognizes keratin polypeptides with a wide range of molecular weights and can be applied in diagnostic panels for tumors of unknown origin. Using tissue microarray technology, we tested 1059 lymphoma and acute leukemia cases, covering the most common disease entities, for aberrant CK expression, using CK22. In total, 866 of the arrayed cases were evaluable (80%), and 13 positive cases (1.5%) were found: 1 out of 230 Hodgkin lymphomas (0.4%), 1 plasma cell myeloma, 2 out of 326 diffuse large B-cell lymphomas (0.6%), 5 out of 18 mantle cell lymphomas (26%), 3 out of 70 small cell lymphomas/chronic lymphocytic leukemias (4%) and 1 out of 27 peripheral T-cell lymphomas, not otherwise specified (4%). Immunostaining was finely granular in most cases, and the total amount of positively staining cells exceeded 10% only in the cases of Hodgkin lymphoma and plasmocytoma. All CK22-positive cases, except for one mantle cell lymphoma, expressed the specific simple epithelial CK8 but not the basal/stratified epithelial CK5/6. Aberrant CK expression can be encountered in a small subset of otherwise characteristic B- and T-cell lymphomas, but not in acute leukemias, which should be considered in difficult differential diagnostic settings.

Androgen-dependent regulation of Her-2/neu in prostate cancer cells.

The mechanisms underlying the progression of prostate cancer to a state of resistance to hormone ablation remain poorly understood. Here, we have investigated the relationship between androgen receptor (AR) and Her-2/neu in prostate cancer cells. Overexpression of Her-2/neu (c-ErbB2) activates the AR pathway and confers a survival and growth advantage to prostate cancer cells in an androgen-deficient milieu. In vitro, the absence of androgens or AR blockade induced Her-2/neu protein expression and phosphorylation. In contrast, upon readministration of androgens, Her-2/neu mRNA, protein, and phosphorylation levels decreased linearly with increasing concentrations of dihydrotestosterone as LNCaP cells reentered the cell cycle. In vivo, induction of Her-2/neu by castration in orthotopically injected LNCaP cells resulted in a progressive increase in prostate-specific antigen secretion into the mouse serum, indicating that Her-2/neu-mediated, AR-dependent transcription occurs following castration and results in tumor cell growth. Finally, selection of LNCaP cells stably transfected with short hairpin RNA specific for AR resulted in Her-2/neu overexpression. Similarly, knockdown of Her-2/neu led to induction of AR. However, when Her-2/neu and AR were simultaneously targeted, we observed cell death, whereas surviving cells retained low level expression of Her-2/neu. Thus, induction and activation of Her-2/neu occurs in an androgen-depleted environment or as a result of AR inactivation, promoting ablation-resistant survival of prostate cancer cells. These data provide the biochemical rationale to target Her-2/neu in hormone-refractory prostate cancer.

Estimating iron overload in patients with suspected liver disease and elevated serum ferritin.

BACKGROUND: Iron status evaluation in patients with suspected liver disease and elevated serum ferritin is often challenging because hyperferritinemia does not always indicate iron overload. A reliable approach to estimate iron overload without exposing the patient to unnecessary investigations would help the clinician to identify patients who may take advantage of iron-removal therapy. METHODS: We analyzed all liver biopsies, including measurement of hepatic iron concentration, performed at the University Hospital Zurich from 1997 to 2010 to identify clinical and laboratory predictors of iron overload in patients with elevated serum ferritin (n = 147). RESULTS: Hyperferritinemia was predictive of iron overload only in patients with a high level of serum ferritin (>2000 µg/L). In patients with moderate hyperferritinemia, liver transaminases inversely correlated with hepatic iron concentration. A combination of both parameters expressed as ferritin/aspartate transaminase ratio was highly predictive of tissue iron overload (sensitivity 83.3%, specificity 78.6%). Receiver operating characteristic analysis resulted in an area under the curve of 0.83. CONCLUSIONS: We established a simple and reliable method to correctly estimate iron overload in patients with suspected liver disease and elevated serum ferritin.

Liver Transplantation because of Acute Liver Failure due to Heme Arginate Overdose in a Patient with Acute Intermittent Porphyria.

In acute attacks of acute intermittent porphyria, the mainstay of treatment is glucose and heme arginate administration. We present the case of a 58-year-old patient with acute liver failure requiring urgent liver transplantation after erroneous 6-fold overdose of heme arginate during an acute attack. As recommended in the product information, albumin and charcoal were administered and hemodiafiltration was started, which could not prevent acute liver failure, requiring super-urgent liver transplantation after 6 days. The explanted liver showed no preexisting liver cirrhosis, but signs of subacute liver injury and starting regeneration. The patient recovered within a short time. A literature review revealed four poorly documented cases of potential hepatic and/or renal toxicity of hematin or heme arginate. This is the first published case report of acute liver failure requiring super-urgent liver transplantation after accidental heme arginate overdose. The literature and recommendations in case of heme arginate overdose are summarized. Knowledge of a potentially fatal course is important for the management of future cases. If acute liver failure in case of heme arginate overdose is progressive, super-urgent liver transplantation has to be evaluated.

Targetable molecular pathways in classical Hodgkin's lymphoma.

INTRODUCTION: most patients with classical Hodgkin's lymphoma (cHL) are cured by stage-adapted multimodal regimens. However, some will suffer from refractory disease or experience a relapse. Furthermore, late toxicity due to aggressive chemotherapy and/or radiotherapy has become an increasing problem in long-term survivors. Special situations, such as cHL in a post-transplant setting and patients not able to tolerate standard therapy, are also challenging. Targeting molecular pathways could be a way to find solutions for these varied aspects. AREAS COVERED: research undertaken by leading experts in the field of cHL is summarized. The literature search encompasses all data available via PubMed or published (pre-)clinical trials until August 2010. We discuss the crucial molecular pathways in cHL, novel agents that may be utilized to interact with these pathways, and insights into the results of current clinical trials utilizing these novel therapeutics. EXPERT OPINION: the most important oncogenic pathways in cHL are loss of B-cell identity by the neoplastic cells, activation of the NF-κB pathway, and constitutive activation of the JAK2-STAT-pathway. Both monoclonal antibodies and small-molecule inhibitors are potentially useful agents to target these pathways.

Expression of histone deacetylases 1, 2 and 3 in histological subtypes of testicular germ cell tumours.

In this study we aimed to evaluate the protein expression of class I histone deacetylases (HDAC) in testicular germ cell tumours (GCT) and to analyse differences between the histological subtypes of testicular GCT. 325 testicular GCT were included in a tissue microarray with each histological subtype of the tumour being separately represented on this array. Expression of class I HDAC isoforms 1, 2 and 3 was assessed by immunohistochemistry. While HDAC2 and 3 were highly expressed in all histological subtypes of GCT, HDAC1 was almost consistently expressed at lower levels. We observed significant differences in the expression of the respective HDACs between seminoma and non-seminoma GCT tissue components. Interestingly, choriocarcinomas showed generally high expression values for all three class I HDAC isoforms. Relevant correlations with clinicopathological parameters could not be demonstrated. Contrasting published findings on other tumour entities, no immediate practical diagnostic or prognostic value for HDAC1-3 in GCT could be inferred. However, the high expression levels might still be indicative for a treatment response to HDAC inhibitors which ought to be evaluated in further studies.

Class I histone deacetylases 1, 2 and 3 are highly expressed in classical Hodgkin's lymphoma.

OBJECTIVE: HDAC inhibitors (HDI) are anti-neoplastic drugs with preliminary successful clinical applications in Hodgkin's lymphoma (HL). Systematic investigations of HDAC expression in HL, based on histology and immunohistochemistry are yet rare. RESEARCH DESIGN/METHODS: We investigated the expression of HDAC1, 2 and 3 in 283 HL on tissue microarrays. MAIN OUTCOME MEASURES: Expression of HDAC isoforms was scored in Hodgkin and Reed-Sternberg cells (HRSC) and background infiltrate and compared with freedom of treatment failure (FTF) in 118 cases, for which all data was available. RESULTS: All analyzable HL expressed the HDAC isoforms 2 (n = 194) and 3 (n = 207) in over 50%, mostly 100%, of HRSC and almost all background lymphocytes. HDAC1 was expressed in 169 of 179 analyzable HL in a mean of 82% and in 172 out of 179 analyzable cases in a mean of 83% of infiltrating lymphocytes. HDAC1 of below 75% in HRSC correlated with worse FTF with 16 out of 32 events, compared with 16 out of 82 in cases with over 75% HDAC1-expressing HRSC. CONCLUSION: HDAC isoforms 1, 2 and 3 are highly expressed in HL. In addition, decreased HDAC1 expression is accompanied by worse outcome in HL.

Diagnostic utility of the B-cell lineage markers CD20, CD79a, PAX5, and CD19 in paraffin-embedded tissues from lymphoid neoplasms.

The specificity and sensitivity of CD19, CD20, CD79a, and PAX5 for detection of B-cell lineage lymphoma/leukemia derivation was determined on tissue microarrays containing 148 Hodgkin lymphomas, 358 B-cell and 16 T-cell lymphomas, 50 myelomas, and 69 acute leukemias. In mature lymphoid neoplasms, receiver-operating characteristic curve analysis showed CD20 to be the most sensitive, and CD20 and CD79a the most specific markers for B-lineage derivation. CD19 had the weakest specificity, because it was expressed in 3 T-cell lymphomas, but its sensitivity was better than CD79a. In Hodgkin lymphoma cases, the presence of B-cell markers in Hodgkin and Reed-Sternberg cells decreased in the following order: PAX5>CD20>CD79a>CD19. CD19 and PAX5 were not detectable in myelomas. In acute leukemia, CD20 turned to be the most specific, and PAX5 and CD19 the most sensitive markers for B-lineage derivation. In conclusion, an optimal B-cell lineage panel for daily routine on paraffin-embedded tissues should consist of CD20 and CD79a, and eventually, PAX5 for mature lymphoid neoplasms and PAX5 and CD19, and eventually, CD20 in (acute) precursor cell leukemias, because they cover most of the sensitivity and specificity needed.

Clinical, phenotypic and genetic similarities and disparities between post-transplant and classical Hodgkin lymphomas with respect to therapeutic targets.

OBJECTIVE: Post-transplant Hodgkin lymphoma (ptHL) is a rare but serious complication. We explored the clinical, phenotypic and genetic similarities and disparities between ptHL and classical Hodgkin lymphoma (cHL) in immunocompetent patients and sought proteins/pathways in ptHL that might have potential as therapeutic targets. RESEARCH DESIGN AND METHODS: Eight ptHL cases in solid organ recipients (mean patient age 36 years; mean duration between organ transplant and onset of ptHL 80 months) were phenotypically and genotypically analyzed and the results were compared with known phenotypic and molecular characteristics of cHL. RESULTS: All ptHL expressed CD15, CD30 and LMP-1 of EBV; the B-cell markers BOB-1, Oct2, CD79a and CD20 were more commonly expressed in ptHL versus cHL (100%, 86%, 50% and 38% in ptHL compared to 6%, 14%, 10% and 33% in cHL, respectively); all ptHL expressed phosphoinositide 3-kinase (PI3K) versus 81% of cHL; 2/6 (33%) ptHL displayed gains at 9p24 that were similar to cHL (32%). The JAK2 downstream pSTAT3 slightly predominated in ptHL versus cHL (60% versus 50%). Clonal immunoglobulin gene rearrangements were found in 2/4 cases. CONCLUSIONS: ptHL and cHL are closely related, but not identical, neoplasms, with the primary differences being the strict association with EBV infection, persistent phenotypic B-cell signature and high expression of PI3K as well as the slightly CD4-depleted but TIA-1/Granzyme B-enriched cellular background composition in ptHL.

Primary diffuse large B-cell lymphomas of the bone: prognostic relevance of protein expression and clinical factors.

Diffuse large B-cell lymphomas can be considered primary bone tumors if they are monostotic or polyostotic, affecting multiple skeletal sites without visceral or lymph node involvement. They are rarely considered as extranodal lymphomas or as bone tumors, respectively. To elucidate the prognostic relevance of clinicopathologic characteristics in such disease, we collected a cohort of primary diffuse large B-cell lymphomas of the bone and retrospectively investigated 33 patients. The cohort encompassed the years 1975 to 2004. Protein expression patterns were identified by immunohistochemistry applied to a tissue microarray. The patients included 23 males (mean age, 37 years) and 10 females (mean age, 54 years). Disease stage was I and II in 30 and IV in 3 patients. Within the mean follow-up of 28 months, 6 patients died. Median overall survival was reached after 78 months. Clinical factors favoring a good prognosis were age younger than 53 and administration of chemotherapy. Of the phenotypic markers analyzed (CD10, CD44s, CD138, Bcl-2, Bcl-6, MUM1, and Ki-67), MUM1 expression in more than 10% of the tumor cells and CD10 expression in less than 55% as well as a nongerminal center signature substantiated adverse outcome in a univariate model. In summary, poor survival in PB-DLBCL was clearly predicted in patients older than 53, who had not received chemotherapy, and who demonstrated MUM1 expression and nongerminal center phenotype.

Clinical characteristics of dementia associated with argyrophilic grain disease.

BACKGROUND/AIMS: We aimed at characterizing the clinical features of dementia associated with argyrophilic grain disease (AgD). METHODS: Relatives or close friends of 24 individuals with autopsy-confirmed AgD and 29 patients with autopsy-confirmed Alzheimer's disease (AD) were administered a novel Retrospective Dementia Inventory to assess the cognitive, behavioral and affective symptoms of the deceased patients. RESULTS: AgD patients showed less severe impairments in memory, language, attention and executive function than AD patients. CONCLUSION: Compared to AD patients, individuals suffering from AgD appear to present with comparable deficits in behavior and affect but relatively spared cognitive functioning.

Diffuse idiopathic neuroendocrine cell hyperplasia causing severe airway obstruction in a patient with a carcinoid tumor.

We report a 57-year-old female with severe airway obstruction who underwent resection of a tumor of unknown dignity during lung volume reduction surgery. The nodule consisted of a well-differentiated neuroendocrine tumor (carcinoid), and severe chronic obstructive lung disease was due to diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, a very rare cause of obliterative bronchiolitis. Radionuclide ablative therapy of the neuroendocrine tissue was considered but not found to be feasible due to a low lung/background ratio of the radiotracer.