Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

KRAS genotyping of paraffin-embedded colorectal cancer tissue in routine diagnostics: comparison of methods and impact of histology

KRAS mutation testing before anti-epidermal growth factor receptor therapy of metastatic colorectal cancer has become mandatory in Europe. However, considerable uncertainty exists as to which methods for detection can be applied in a reproducible and economically sound manner in the routine diagnostic setting. To answer this question, we examined 263 consecutive routine paraffin slide specimens. Genomic DNA was extracted from microdissected tumor tissue. The DNA was analyzed prospectively by Sanger sequencing and array analysis as well as retrospectively by melting curve analysis and pyrosequencing; the results were correlated to tissue characteristics. The methods were then compared regarding the reported results, costs, and working times. Approximately 40% of specimens contained KRAS mutations, and the different methods reported concordant results (kappa values >0.9). Specimens harboring fewer than 10% tumor cells showed lower mutation rates regardless of the method used, and histoanatomical variables had no influence on the frequency of the mutations. Costs per assay were higher for array analysis and melting curve analysis when compared with the direct sequencing methods. However, for sequencing methods equipment costs were much higher. In conclusion, Sanger sequencing, array analysis, melting curve analysis, and pyrosequencing were equally effective for routine diagnostic KRAS mutation analysis; however, interpretation of mutation results in conjunction with histomorphologic tissue review and on slide tumor tissue dissection is required for accurate diagnosis.

Inter-laboratory validation of PCR-based HPV detection in pathology specimens

The detection and typing of human papilloma virus (HPV) in pathology specimens is gaining increasingly in importance. In the context of the initiative for quality assurance in pathology (QuIP) of the German Society of Pathology and the Professional Association of German Pathologists, four panel laboratories with experience and expertise in polymerase chain reaction (PCR)-based HPV detection were selected to establish an inter-laboratory trial. In a first step, these laboratories performed an internal testing of their own methodologies, which comprised DNA sequencing, multiplex nested PCR and hybridization techniques. Material from 39 samples including paraffin sections and DNA preparations of tissues and plasmids were evaluated by each panel institute according to their own protocols. Despite the different methodologies, a high degree of inter-laboratory reliability was achieved. In this report, we summarise the results. Pretested specimens are available for the external trail and can be ordered from the steering institute via provitro GmbH Berlin ( http://www.provitro.de ). Supplementary data are online available at http://pathologie-ccm.charite.de (rubric "Forschung"), which includes a web-based photo gallery of HPV-associated lesions and their potential association with specific virus types. The initiative is intended to foster the quality assurance of molecular HPV analysis in pathology and its correlation with morphological changes.

HPV typing and CGH analysis for the differentiation of primary and metastatic squamous cell carcinomas of the aerodigestive tract

Human papilloma virus (HPV) typing and Comparative Genomic Hybridisation (CGH) analysis can be used in the classification of multiple tumours of the aerodigestive tract for the differentiation between secondary malignancy versus metastasis. We present 3 exemplary cases of patients with multiple squamous cell carcinomas, localised within the head and neck region, cervical lymph node and the lung. In two patients, HPV typing identified HPV type 16 in the tonsillar carcinomas and the corresponding cervical lymph node and lung carcinoma indicating that the latter were metastatic spreads. In case 1, CGH confirmed the clonal relationship. Case two showed a peculiar syncytial growth pattern with lymphocytic infiltration which may constitute a potential morphological marker for HPV infection. In case three, a vallecular carcinoma was HPV negative while a lung cancer was positive for HPV type 6 indicating two independent primary tumours. Our case triplet illustrates the variability of HPV infection in squamous cell cancer of the aerodigestive tract and power as well as limitations of morphology, HPV typing and tumour genetics in the classification of multiple tumours.

Chromosomal imbalances in brain metastases of solid tumors

Metastases account for approximately 50% of the malignant tumors in the brain. In order to identify structural alterations that are associated with tumor dissemination into the central nervous system we used Comparative Genomic Hybridization (CGH) to investigate 42 brain metastases and 3 primary tumors of 40 patients. The metastases originated from lung cancer (14 cases), melanomas (7), carcinomas of breast (5), colon (5), kidney (5), adrenal gland (1) and thyroid (1). In addition, tumors of initially unknown primaries were assessed in 3 cases. The highest incidence of DNA gains were observed for the chromosomal regions 1q23, 8q24, 17q24-q25, 20q13 (>80% of cases) followed by the gain on 7p12 (77%). DNA losses were slightly less frequent with 4q22, 4q26, 5q21, 9p21 being affected in at least 70% of the cases followed by deletions at 17p12, 4q32q34, 10q21, 10q23-q24 and 18q21-q22 in 67.5% of cases. Two unusual narrow regional peaks were observed for the gain on 17q24-q25 and loss on 17p12. The incidence at individual loci can be viewed at our CGH online tumor database at http:// amba.charite.de/cgh/. The metastases of each tumor type showed a recurrent pattern of changes. In those cases with primary tumor and metastases available, the CGH pattern exhibited a high degree of conformity. In conclusion, our data suggests that specific genetic lesions are associated with tumor dissemination into the nervous system and that CGH analysis may be a useful supplementary tool for classification of metastases with unknown origin.

[Squamous cell carcinoma in lupus vulgaris]

Lupus vulgaris and carcinoma in lupo have become rare events that take place in the developed countries only under special circumstances. A 53-year-old woman developed such a carcinoma. She suffered from alcoholism, a well known risk factor for tuberculosis. The diagnosis of lupus vulgaris was confirmed by biopsy when an erythematous lesion on her arm that had been present for 25 years enlarged and subsequently ulcerated. Chemotherapy was discontinued because of lack of compliance and the ulcer grew markedly over the following 16 months. Therefore the entire lesion was excised. Histology showed a squamous cell carcinoma within the ulcer. Neither further systemic manifestations of tuberculosis nor metastases of the carcinoma were found. Under continuous combined antituberculous therapy, the patient remained free of symptoms. This case underlines the problems associated with a disease that has been nearly forgotten in the western countries. It also shows that alcoholism is a risk factor for tuberculosis, along with debilitating diseases such as lymphoma and AIDS as well as immunosuppressive therapy.

Parvovirus B19 infection associated with unilateral cervical lymphadenopathy, apoptotic sinus histiocytosis, and prolonged fatigue

This report describes the case of a 16 year old girl with a history of high fever, prolonged fatigue, and cervical lymphadenopathy of the right side. In addition, the patient showed neutropenia, thrombopenia, and pronounced reticulopenia. Cervical ultrasound showed unilateral hypoechoic lymph nodes up to 23 mm in diameter suspicious for malignant lymphoma. Histology of a cervical lymph node specimen revealed massive nodular histiocytic proliferation and prominent apoptosis without necrosis. Parvovirus B19 was detected by polymerase chain reaction and immunohistochemistry in the lymph node. In summary, this case is an unusual presentation of parvovirus B19 infection. The virus was identified as the potential causative agent of unilateral cervical lymphoma and apoptotic sinus histocytosis, thus broadening the clinicopathological spectrum of parvovirus B19 induced diseases.

Inter-laboratory validation of PCR-based detection of Mycobacterium tuberculosis in formalin-fixed, paraffin-embedded tissues

The present study is based on the initiative for quality assurance in pathology of the German Society of Pathology and the Professional Association of German Pathologists. Four panel laboratories with experience and expertise in polymerase chain reaction (PCR) detection of Mycobacterium tuberculosis were selected to establish the prerequisites for continuous external laboratory trials, in particular, by providing pre-tested specimens and evaluation criteria for participating institutes. In the first step, the four panel laboratories performed an internal trial to test their own reliability and reproducibility. Paraffin sections and DNA preparations from 34 tissues (25 clinical specimens and 9 controls) totalling to 66 samples were evaluated by each panel institute according to their own protocols. The methodologies differed and are described in detail. Despite these differences, a high degree of inter-laboratory reliability was achieved. In this report, we summarise our results including the correlation with the histology and provide recommendations for applying PCR-based methodology for the detection of mycobacterial DNA in surgical specimens. Supplementary data are available online at http://www.charite.de/ch/patho (rubric "Forschung"). Pre-tested specimens are now available for the external trial and can be ordered from the steering institute via Oligene (http://www.oligene.com/). All molecular pathology laboratories are invited to participate in this quality assurance initiative.

Cytomegalovirus is not associated with progression and metastasis of colorectal cancer

Recently, it was hypothesized that human cytomegalovirus (HCMV) might be associated with colorectal cancer progression. However, the role of HCMV infection in colorectal cancer remains controversial. We aimed to assess whether nucleic acids and/or gene products of HCMV could be detected in primary and metastatic colorectal carcinomas. Fresh-frozen biopsy specimens from 77 primary and metastatic colorectal carcinomas of randomly selected patients were analyzed by PCR and immunohistochemistry. We investigated 57 primary tumors and 20 metastases, comprising 13 tumor pairs from the same patient. In PCR, four primary tumors showed a positive CMV result whereas all investigated metastases were negative including three paired samples from positive primaries. In immunohistochemistry, no specific staining could be determined in all neoplastic epithelial cells. In summary, we think that there is no association between CMV infection and tumor progression or metastasis formation of colorectal cancer.

Nucleolin as activator of human papillomavirus type 18 oncogene transcription in cervical cancer

High risk human papillomaviruses (HPVs) are central to the development of cervical cancer and the deregulated expression of high risk HPV oncogenes is a critical event in this process. Here, we find that the cell protein nucleolin binds in a sequence-specific manner to the HPV18 enhancer. The DNA binding activity of nucleolin is primarily S phase specific, much like the transcription of the E6 and E7 oncoproteins of HPV18 in cervical cancer cells. Antisense inactivation of nucleolin blocks E6 and E7 oncogene transcription and selectively decreases HPV18(+) cervical cancer cell growth. Furthermore, nucleolin controls the chromatin structure of the HPV18 enhancer. In contrast, HPV16 oncogene transcription and proliferation rates of HPV16(+) SiHa cervical cancer cells are independent of nucleolin activity. Moreover, nucleolin expression is altered in HPV18(+) precancerous and cancerous tissue from the cervix uteri. Whereas nucleolin was homogeneously distributed in the nuclei of normal epithelial cells, it showed a speckled nuclear phenotype in HPV18(+) carcinomas. Thus, the host cell protein nucleolin is directly linked to HPV18-induced cervical carcinogenesis.

Fatal atypical T-cell proliferation associated with Epstein-Barr virus infection

We report the case of a young Caucasian man who presented with polyneuropathy and severe, ultimately fatal, congestive heart failure in the context of a chronic active Epstein-Barr virus (EBV) infection. Post-mortem examination revealed both monoclonal and polyclonal proliferation of EBV-positive atypical T lymphocytes within different organs. Predominant infiltration of the nervous system and heart with extensive myocardial scarring accounted for the clinical symptoms. The remarkable features of this case are (i) the occurrence in a Caucasian patient, (ii) the absence of detectable immunodeficiency, and (iii) the myocardial destruction by EBV-infected monoclonal T cells.

Telomerase activity in cervical smears

It is well known that almost all carcinoma cells including those of the uterine cervix have re-established their telomerase activity. However, until now there is no conclusive picture on the telomerase activity in cervical dysplasias and about their relationship to HPV infection. To investigate this question, material from 34 patients (15 with normal epithelium, 11 with LGSIL, 8 with HGSIL) obtained by conventional cervical brushing was used and subjected to non-radioactive TRAP-ELISA (Boehringer Mannheim). The HPV analysis was performed by PCR on formalin-fixed, paraffin-embedded biopsy material obtained after cytological investigation. We could show that telomerase activity is detectable in normal cervical epithelium, and that an gradual increase exists for both telomerase activity and HPV positivity from normal epithelium to HGSIL. However, HPV infection and telomerase activity appear to be independent of each other. The high frequency of telomerase positivity in patients with normal cervical epithelium indicates that telomerase activity is not a useful differential diagnostic aid. Whether patients with telomerase-positive dysplasias have a higher probability to progress into an invasive carcinoma remains to be clarified by follow-up studies.

[PCR based diagnosis in pathology]

PCR-based diagnosis of infectious diseases has developed into an important method in surgical pathology. We summarize our experience in this area based on 3500 analyses performed during the past 5 years. The peculiarity of material from a pathological laboratory is the risk of DNA fragmentation as a consequence of tissue fixation. For this reason the assays used must be adapted to this particular situation. PCR-based diagnosis of infectious diseases, if performed according to appropriate quality standards, is a safe and effective technique with high sensitivity and specificity and results in an etiologically based diagnosis.

Human papilloma virus status and chromosomal imbalances in primary cervical carcinomas and tumour cell lines

Human papilloma virus (HPV) infection is the crucial step in the initiation of cervical carcinomas. In addition, HPV18 has been implicated in tumour progression and adverse clinical outcome. We determined the HPV types in 12 primary cervical carcinomas and 12 cell lines and compared the findings with the comparative genetic hybridisation (CGH) pattern of chromosomal alterations. The most frequent alteration was the deletion at 3p14 followed by the loss of 2q34-q36 along with 3q gain. High risk HPV types were detected in all samples except one primary tumour. In contrast to the normal distribution, HPV18 was present in 75% of cases including all cell lines. The cell lines carried a higher number of genetic alterations and a different CGH pattern for several chromosomes than the primary tumours, despite microdissection. Purely HPV18 positive cases indicated a high incidence of imbalances at specific loci with peaks of the histogram coinciding with known HPV integration sites. The study suggests that HPV infection is associated with a recurrent pattern of chromosomal changes in cervical carcinomas and that the development and progression of these alterations is triggered by integration into the host genome.

Strong inhibition of mammalian lipoxygenases by the antiinflammatory seleno-organic compound ebselen in the absence of glutathione

Both human recombinant 5-lipoxygenase (EC 1.13.11.34) and 15-lipoxygenase (EC 1.13.11.33, mammalian enzyme) purified from rabbit reticulocytes were inhibited in the absence of glutathione (GSH) by submicromolar concentrations of the seleno-organic compound ebselen. These concentrations were comparable to those of the enzymes. Soybean lipoxygenase-1 (EC 1.13.11.33, plant enzyme) was not inhibited, whereas prostaglandin endoperoxide synthase-1 (EC 1.14.99.1) was inhibited only at much higher concentrations of ebselen (IC50 = 37.7 +/- 4.3 microM). The action of ebselen on reticulocyte 15-lipoxygenase (IC50 = 0.17 +/- 0.01 microM) was studied in detail. Inhibition occurred instantaneously and appeared to be reversible and was largely abolished by a 20-fold molar excess of GSH over ebselen. In the presence of 1 mM GSH 50% inhibition was observed only at ebselen concentrations as high as 234 +/- 27 microM. 13S-hydroperoxy-9Z, 11E-octadecadienoic acid, the lipoxygenase product formed from linoleic acid, augmented the inhibitory effect at low concentrations and caused a partial reversal at high concentrations. A variety of derivatives or structural analogues of ebselen were also tested and proved to be either inactive or weaker inhibitors of 15-lipoxygenase. We have concluded that the potent inhibition of 15-lipoxygenase by ebselen is due neither to GSH peroxidase-like activity nor to lowering of the hydroperoxide tone. The pharmacological implications of these unique characteristics of the action of ebselen on lipoxygenases are then discussed.

Inhibitory effects of sulfonated shale oils (ammonium bituminosulphonates, Ichthyols) on enzymes of polyenoic fatty acid metabolism

The two commercial pharmaceutical preparations of ammonium bituminosulphonates, Leukichthol and Dark Ichthyol, were shown to inhibit the formation of 5S-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-HETE) from external arachidonic acid by human polymorphonuclear leukocytes stimulated by ionophore A-23187 in a dose-dependent manner. Pure arachidonate 15-lipoxygenases from rabbit reticulocytes and soya beans, and the particulate prostaglandin endoperoxide synthase from sheep vesicular glands, were also inhibited. With the reticulocyte lipoxygenase, the Ichthyols suppressed the enzyme activity by two different mechanisms: (1) a prolongation of the lag period typical of lipoxygenase catalysis, and (2) by a lowering of the maximal enzymatic activity after the end of lag period. As expected, the first effect was reversed by the addition of the lipoxygenase product 13S-hydroperoxy-9Z,11E-octadecadienoic acid (13-HpODE). Ammonium bituminosulphonates are thus universal inhibitors of lipoxygenase activities, and the latter are of potential importance in inflammatory dermatoses.

Experience with the particulate prostaglandin endoperoxide synthase assay for testing non-steroidal antiinflammatory drugs

A microsomal prostaglandin endoperoxide synthase preparation was obtained from sheep vesicular glands and used as a test system for non-steroidal antiinflammatory drugs. The activity was measured oxygraphically with arachidonic acid as substrate. The assay conditions were optimized with respect to the concentrations of enzyme, substrate and hydroperoxidase co-substrate as well as preincubation. The validity of the test was assessed by eight known prostaglandin H synthase inhibitors and two antiinflammatory drugs not acting on this enzyme. Sodium diclofenac proved to be the most potent inhibitor. As shown with indometacin as example the test shows a good reproducibility. The data were fitted to a kinetic mathematical model assuming two distinct inhibitor binding sites with different affinities. This model gave in most cases a good fitting of the experimental data.