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Featured researches published by Ahmad Amanzada.


PLOS ONE | 2013

Interferon-λ4 (IFNL4) Transcript Expression in Human Liver Tissue Samples

Ahmad Amanzada; Waltraut Kopp; Ulrich Spengler; Giuliano Ramadori; Sabine Mihm

Eradication of hepatitis C virus (HCV) infection, both spontaneous and treatment-induced, is marked by the wildtype allele C of a single nucleotide polymorphism upstream of the IL28B gene, rs12979860. This favorable allele was recently described to be in linkage disequilibrium with the wildtype allele TT of a dinucleotide polymorphism, ss469415590, located within a new protein-coding gene. While the TT allele introduces a frame-shift and disrupts the open reading frame, only the variant allele, ΔG, creates a novel type III interferon (IFN) protein, IFN-λ4/IFNL4. Absence of IFNL4 is thus supposed to favor resolution of HCV infection. As to date IFNL4 mRNA transcription has only been investigated in polyI:C-stimulated primary human hepatocytes and not yet in HCV infection in vivo, this study analyzed IFNL4 mRNA expression in human liver biopsy specimens. Samples were obtained from patients with a broad panel of disorders including no liver disease, liver diseases of non-viral etiology, chronic hepatitis B and chronic hepatitis C. Hepatic IFNL4 transcripts were detectable exclusively in a subgroup of chronic hepatitis C patients (24/45). Their amounts were positively related to liver HCV RNA copy numbers (p = 0.0023, r = 0.56) suggesting that the hepatic viral load influences IFNL4 transcription irrespective of IFNL4 governing genotype. Both, the IFNL4 creating allele ΔG (p<0.0001) and actual IFNL4 transcription (p = 0.0015) were found to be correlated to the activation of IFN stimulatory genes (ISGs). By contrast, IFNL4 ss469415590 genotypes were not found to be related to IFN-λ2/3/IL28 or IFN-λ1/IL29 gene expression. In conclusion, this study is the first report on intrahepatic transcript levels of the recently discovered IFNL4 gene. Data indicate that HCV infection in particular might activate IFNL4 transcription in the liver. It provides a possible explanation as to why hepatitis C patients show ISG stimulation in their livers in the apparent absence of an induction of other IFN subtypes.


Laboratory Investigation | 2014

Induction of chemokines and cytokines before neutrophils and macrophage recruitment in different regions of rat liver after TAA administration

Ahmad Amanzada; Federico Moriconi; Tümen Mansuroglu; Silke Cameron; Giuliano Ramadori; Ihtzaz Ahmed Malik

Single-dose thioacetamide (TAA) administration induces inflammation and acute liver damage. The mechanism of inflammatory cell recruitment in the liver is still unclear. The aim of this study was to examine the sequence and recruitment of inflammatory cells in different liver regions in relation to CXC- and CC-chemokine and cytokine expression during acute liver injury. Single-dose TAA was administered to rats intraperitoneally, and animals were killed at different time points thereafter. Serum and liver tissue were taken and frozen immediately. Tissue was used for immunostaining cryostat sections, RNA, and protein extraction. RT-PCR and western blotting were performed for RNA and protein analysis, respectively. An early increase (3 h) in CXCL8/IL-8 levels was measured followed by a marked release in MCP1/CCL2 (24 h) serum levels after TAA administration compared with controls. Similarly, an early increase in specific RNA of hepatic chemokines CXCL1/KC and CXCL8/IL-8 was found at 3 h, followed by an upregulation of CXCL5/LIX (6 h), CXCL2/MIP-2 (12 h), and MCP1/CCL2 gene expression at 24–48 h. Further, an induction of pro-inflammatory cytokines IFN-γ and IL-1β followed by IL-6 and TNF-α was observed with a maximum at 12 h. The magnitude of increase in gene expression of TNF-α and MCP1/CCL2 was the highest among all cytokines and chemokines, respectively. By means of immunohistochemistry, an early (12–24 h) increase in the number of only neutrophil granulocytes (NGs) attached to and around portal vessel walls was observed, followed by increased numbers of mononuclear phagocytes (24–48 h) along the sinusoids. Treatment of the human monocytic cell line U-937 with TNF-α increased the gene expression of CXCL1/KC, CXCL8/IL-8, and MCP1/CCL2. Conversely, adding of infliximab (IFX) to the culture medium inhibited this upregulation significantly. In conclusion, single-dose TAA administration induces a sequence of events with a defined upregulation of gene expression of inflammatory chemokines and cytokines and a transient accumulation of NGs within the portal area and macrophages along the sinusoids throughout the liver. Periportal inflammation seems to precede hepatocellular damage.


Case Reports in Oncology | 2010

A Case Report of a Patient with Hereditary Hemorrhagic Telangiectasia Treated Successively with Thalidomide and Bevacizumab

Ahmad Amanzada; Gwen-Jana Töppler; Silke Cameron; Harald Schwörer; Giuliano Ramadori

Hereditary hemorrhagic telangiectasia is characterized by mucocutaneous and visceral telangiectasia and involves several organs with vascular malformations. It is an autosomal dominant disease and is distinguished into three types, which are due to mutations in different genes. The common symptom is anemia, causing a continous need of blood transfusion. Depending on the severity and disease manifestation, there are various forms of therapy ranging from local therapy activities to operations or drug therapy. Here we describe a dramatic improvement of a patient with a high transfusion frequency due to severe recurrent anemia successively treated with thalidomide and bevacizumab.


Digestion | 2012

High predictability of a sustained virological response (87%) in chronic hepatitis C virus genotype 1 infection treatment by combined IL28B genotype analysis and γ-glutamyltransferase/alanine aminotransferase ratio: a retrospective single-center study.

Ahmad Amanzada; Armin Goralczyk; Simon Schneider; Federico Moriconi; Alexander Lindhorst; Sabine Mihm; D.H. Van Thiel; G. Ramadori

Background: Chronic hepatitis C virus genotype 1 (HCV-G1) infection is treated with pegylated interferon-α and ribavirin. Predictive factors for treatment success are even more important now as direct-acting antiviral agents are available. Methods: Clinical and laboratory parameters were analyzed by uni- and multivariate statistical means in 264 patients with HCV-G1 infections with regard to treatment outcome. Results: The overall sustained virological response (SVR) rate was 44%. Univariate analyses revealed SVRs to be associated with age, high alanine aminotransferase (ALT) and low γ-glutamyltransferase (γ-GT) serum activities, a low pretreatment γ-GT/ALT ratio, rapid virological response (RVR), and absence of steatosis. Multivariate analyses unveiled IL28B rs12979860 genotype (CC vs. CT: OR = 2.8, CI: 1.5–4.9, p = 0.001; CC vs. TT: OR = 7.1, CI: 3.1–16.7, p < 0.001), low pretreatment γ-GT/ALT ratio (OR = 2.5, CI: 1.7–3.3, p < 0.001), age (OR = 0.96, CI: 0.94–0.98, p = 0.001) and RVR (OR = 4.18, CI: 2.85–8.65, p < 0.001) to be significantly related to treatment outcome. Patients with the IL28B rs12979860 CC genotype and a low pretreatment γ-GT/ALT ratio achieved the highest rate of a SVR with the highest predictive values (OR = 26.7, 95% CI: 10–71.1, p < 0.0001). Conclusion: The pretreatment γ-GT/ALT ratio significantly enhances the predictability of the IL28B genotype. Employing this combination will help to identify patients who will most likely benefit from an interferon-α-based combination therapy in a nontriaged ordinary setting.


Journal of Medical Virology | 2012

Early anemia and rapid virological response improve the predictive efficiency of IL28B-genotype for treatment outcome to antiviral combination therapy in patients infected with chronic HCV genotype 1

Ahmad Amanzada; Simon Schneider; Federico Moriconi; Alexander Lindhorst; Thomas Suermann; David H. Van Thiel; Sabine Mihm; Giuliano Ramadori

IL28B genotypes and virological response within 4 weeks are predictors of sustained virological response in patients infected with chronic hepatitis C virus (HCV) genotype 1 treated with antiviral dual combination therapy. The predictive value of “early” anemia (within 4 weeks) alone or in combination with the two other predictors has not been studied yet. A total of 305 pegylated interferon‐α and ribavirin‐treated patients with HCV genotype 1 were included in this study. Hemoglobin values at week 0, 4, 8, and 12 as well as the predictive efficiency of early anemia (hemoglobin value below the gender‐specific lower limit: female < 11.5; male < 13.5 g/dl) during therapy were assessed with IL28B genotypes and rapid virological response. Forty‐eight percent of treated patients developed early anemia. In both females and males (64%), a decrease of hemoglobin concentration of 3 g/dl (female: 14.7 ± 1.1 to 11.4 ± 1.3; male: 15.2 ± 1.2 to 12.2 ± 1.5) significantly correlated with sustained virological response. 64% of IL28B‐CC patients showed a sustained virological response. Seventy‐eight percent of patients with rapid virological response definitively eliminated the virus. Early anemia (81:48:41%) and rapid virological response (83:91:92%) increased the predictive efficiency of IL28B rs12979860 genotype distribution (CC:CT:TT). IL28B‐CC and early anemia as well as IL28B‐CC and rapid virological response had an Odds ratio of 42.4 or 75 to achieve a sustained virological response compared to TT without early anemia or rapid virological response. This finding may help to early identify responders to standard PEG‐IFN‐α and ribavirin treatment even within those with unfavorable IL28B genotype. J. Med. Virol. 84: 1208–1216, 2012.


Shock | 2013

Ferritin L is the sole serum ferritin constituent and a positive hepatic acute phase protein

Naila Naz; Federico Moriconi; Shakil Ahmad; Ahmad Amanzada; Sajjad Khan; Sabine Mihm; Guiliano Ramadori; Ihtzaz Ahmed Malik

ABSTRACT Ferritin L (FTL) and ferritin H (FTH) subunits are responsible for intracellular iron storage. Serum ferritin levels are not only dependant on body iron stores. Aims of the present study are to demonstrate nature, source, and major regulatory mediators of serum ferritin in an animal model of acute-phase (AP) response. Animals (rats, wild-type [WT] mice, and interleukin [IL]-6ko mice) were injected with turpentine oil (TO) intra-muscularity to induce a sterile abscess and sacrificed at different time points afterward. Rat hepatocytes were isolated for cell culture and, after reaching confluence, stimulated with major AP cytokines to induce AP conditions. We found a significantly increased expression of both ferritin subunits in liver at mRNA and protein levels during AP response. In the serum of both control and TO-injected rats, only FTL was detectable by Western blotting, whereas no increase in serum FTL was measured by Western blot or enzyme-linked immunosorbent assay. An increase in protein expression of FTL and FTH was observed in lysates of rat hepatocytes after treatment with IL-6, IL-1&bgr;, and tumor necrosis factor-&agr;; however, only FTL was increasingly released into supernatant. In both TO-injected rats and WT mice, a dramatic increase in serum IL-6 levels was observed, along with an increased amount of hepatic ferritin subunits. However, an increase of hepatic FTL but not of FTH protein expression was observed in IL-6ko mice after TO injection. Our data demonstrate that FTL is the only rat serum ferritin whose release into circulation from the hepatocytes is increased by the effect of AP cytokines (e.g., IL-6). In contrast, FTH expression is intracellular in both under physiological and AP conditions.


Journal of Medical Virology | 2013

Vitamin D status and serum ferritin concentration in chronic hepatitis C virus type 1 infection.

Ahmad Amanzada; Armin Goralczyk; Federico Moriconi; David H. Van Thiel; Giuliano Ramadori; Sabine Mihm

The circulating 25‐hydroxylated form of vitamin D3, 25(OH)D, and serum ferritin concentrations have been described to be associated with disease progression in chronic hepatitis C. Both parameters also have been assessed with regard to treatment outcome, however, with divergent results. This study examined both the pre‐ and posttreatment serum concentrations of 25(OH)D and ferritin in 191 patients infected chronically with hepatitis C virus (HCV) type 1 with regard to liver inflammatory activity (grading), disease progression in terms of fibrosis (staging) and an antiviral treatment outcome. Mean pretreatment serum 25(OH)D and ferritin concentrations were 18 ± 10 ng/ml and 280 ± 225 µg/L, respectively. Multivariate analysis revealed lower pretreatment serum 25(OH)D and higher ferritin concentrations to be significantly related to both severity of inflammatory activity and of fibrotic alterations. Pretreatment serum ferritin concentration, furthermore, unlike 25(OH)D concentration, was found to be associated with a sustained virological response by uni‐ and multivariate analyses. A sustained virological response was featured by a significant increase in serum 25(OH)D levels (18 ± 10 ng/ml vs. 22 ± 11 ng/ml; P < 0.01), a reduction of serum ferritin concentration (191 ± 156 µg/L vs. 103 ± 63 µg/L; P < 0.001) and a normalization of serum alanine aminotransferase (ALT) and γ‐glutamyl‐transferase (γ‐GT) activities. Taken together, decreased 25(OH)D and increased ferritin serum levels indicate the severity of hepatic inflammation and fibrosis in patients infected chronically with HCV type 1. Elevated ferritin, furthermore, was found to be an independent predictor for standard IFN‐based therapy responsiveness. J. Med. Virol. 85:1534–1541, 2013.


World Journal of Gastroenterology | 2014

Differential gene expression of chemokines in KRAS and BRAF mutated colorectal cell lines: Role of cytokines

Sajjad Khan; Silke Cameron; Martina Blaschke; Federico Moriconi; Naila Naz; Ahmad Amanzada; Giuliano Ramadori; Ihtzaz Ahmed Malik

AIM To study KRAS/BRAF mutations in colorectal-cancer (CRC) that influences the efficacy of treatment. To develop strategies for overcoming combination of treatment. METHODS Five colonic cell-lines were investigated: DLD-1 with KRAS (G13D) mutation, HT 29 and Colo 205 with BRAF (V600E) mutation as well as the wild type (Wt) cell-lines Caco2 and Colo-320. DLD-1 (KRAS), HT-29 (BRAF) and Caco2 (Wt) cell lines were treated with cytokines (TNFα 50 ng, IL-1β 1 ng and IFNγ 50 ng) and harvested at different time points (1-24 h). KRAS inhibition was performed by the siRNA-approach. Two colorectal cancer cells DLD-1 and Caco2 were used for KRAS inhibition. About 70% confluency were confirmed before transfection with small interferring RNA (siRNA) oligonucleotides. All the synthetic siRNA sequences were designed in our laboratory. Total RNA and protein was isolated from the cells for RT-PCR and Western blotting. Densitometry of the Western blotting was analyzed with the Image J software (NIH). Results are shown as mean ± SD. RESULTS RT-PCR analysis in non-stimulated cells showed a low basal expression of TNFα and IL-1β in the DLD-1 KRAS-mutated cell-line, compared to Caco2 wild type. No detection was found for IL-6 and IFNγ in any of the studied cell lines. In contrast, pro-angiogenic chemokines (CXCL1, CXCL8) showed a high constitutive expression in the mutated cell-lines DLD-1 (KRAS), HT-29 and Colo205 (BRAF), compared to wild type (Caco2). The anti-angiogenic chemokine (CXCL10) showed a high basal expression in wild-type, compared to mutated cell-lines. KRAS down-regulation by siRNA showed a significant decrease in CXCL1 and CXCL10 gene expression in the DLD-1 (KRAS) cell-line in comparison to wild type (Caco2) at 72 h after KRAS silencing. In contrast, the specific KRAS inhibition resulted in an up-regulation of CXCL1 and CXCL10. The results of our study show a higher expression of pro-angiogenic chemokines at basal level in mutated cell-lines, which was further increased by cytokine treatment. CONCLUSION To summarize, basal chemokine gene expression for pro-angiogenic chemokines was high in mutated as compared to wild type cell-lines. This reflects the likely existence of a different microenvironment in tumours consistent of wild type or mutated cells. This may help to rationalize the choice of molecular targets for suitable therapeutic investigation in clinical studies.


Laboratory Investigation | 2012

The anti-TNF- α antibody infliximab indirectly regulates PECAM-1 gene expression in two models of in vitro blood cell activation

Federico Moriconi; Ihtzaz Ahmed Malik; Ahmad Amanzada; Martina Blaschke; Dirk Raddatz; Sajjad Khan; Giuliano Ramadori

Chronic inflammatory bowel diseases can be successfully treated with antibodies against the acute phase mediator TNF-α. The process of activation and of extravasation of inflammatory cells from the blood into the ‘stressed’ tissue site is controlled by cytokines and chemokines, which attract leukocytes and by adhesion molecules, which mediate their attachment and transmigration toward the affected cell(s). The changes in the gene expression of adhesion molecules taking place in those cells before attachment have been less investigated. Changes of PECAM-1, ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1) gene expression were studied in phytohaemagglutinin (PHA)- and lipolysaccharide (LPS)-treated human peripheral blood leukocytes (PBLs), granulocytes and the human monocyte cell line U-937. Cells were treated either with PHA or with LPS in the presence or absence of infliximab and incubated with TNF-α, IFN-γ and/or transforming growth factor beta (TGF-β) and treated as above. Activation of PBLs by PHA or LPS treatment triggered a sharp upregulation of ICAM-1, VCAM-1 gene expression and a time-dependent downregulation of PECAM-1 gene expression reaching a minimum 4 h from start of the experiment. The anti-TNF-α antibody infliximab, by neutralizing TNF-α and IFN-γ production, completely reversed PECAM-1 mRNA downregulation and ICAM-1 and VCAM-1 upregulation. Immunostaining of PBLs cytospins with antibodies against PECAM-1 and ICAM-1 confirmed RT-PCR and western blot results. PBLs IFN-γ or TNF-α treatment downregulated PECAM-1 in parallel with the upregulation of ICAM-1 and VCAM-1 gene expression, whereas TGF-β upregulated PECAM-1- and downregulated ICAM-1 and VCAM-1 gene expression counteracting the effect of TNF-α or IFN-γ. Similar results were obtained in human U937 cells and in granulocyte cultures by TNF-α or IFN-γ treatment. Taken together, these results suggest that infliximab, blocking TNF-α and IFN-γ production, exerts its anti-inflammatory effect through inhibiting downregulation of PECAM-1 gene expression and upregulation of ICAM-1 and VCAM-1 expression in leukocytes of the peripheral blood. These results also suggest that TGF-β may thus be of therapeutic importance as an anti-inflammatory agent.


World Journal of Hepatology | 2014

Predictability of IL-28B-polymorphism on protease-inhibitor-based triple-therapy in chronic HCV-genotype-1 patients: A meta-analysis

Nicolae-Catalin Mechie; Christian Röver; Silke Cameron; Ahmad Amanzada

AIM To investigate the predictability of interleukin-28B single nucleotide polymorphism rs12979860 with respect to sustained virological response (SVR) in chronically hepatitis C virus (HCV) genotype-1 patients treated with a protease-inhibitor and pegylated interferon-α (Peg-INF-α) based triple-therapy. METHODS We searched PubMed, the Cochrane Library and Web of Knowledge for studies regarding the interleukin 28B (IL-28B)-genotype and protease-inhibitor based triple-therapy. Ten studies with 2707 patients were included into this meta-analysis. We used regression methods in order to investigate determinants of SVR. RESULTS IL-28B-CC-genotype patients achieved higher SVR rates (odds 5.34, 95%CI: 3.81-7.49) than IL-28B-non-CC-genotype patients (1.88, 95%CI: 1.43-2.48) receiving triple-therapy. The line of therapy (treatment-naïve or -experienced for Peg-INF-α) did not affect the predictive value of IL-28B (P = 0.1). IL-28B-CC-genotype patients treated with protease inhibitor-based triple-therapy consisting of Boceprevir, Simeprevir, Telaprevir or Vaniprevir showed odds of 3.38, 14.66, 7.84 and 2.91, respectively. The odds for CC genotype patients treated with Faldaprevir cannot be quantified, as only a single study with a 100% SVR rate was available. CONCLUSION IL-28B-SNP predicts the outcome for chronic HCV genotype-1 patients receiving protease inhibitor-based triple-therapy. The predictive value varies between the different protease inhibitors.

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Sabine Mihm

University of Göttingen

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Naila Naz

University of Göttingen

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Silke Cameron

University of Göttingen

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V Ellenrieder

University of Göttingen

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Sajjad Khan

University of Göttingen

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