Identification of new BMP6 pro-peptide mutations in patients with iron overload.

Hereditary Hemochromatosis (HH) is a genetically heterogeneous disorder caused by mutations in at least five different genes (HFE, HJV, TFR2, SLC40A1, HAMP) involved in the production or activity of the liver hormone hepcidin, a key regulator of systemic iron homeostasis. Nevertheless, patients with an HH-like phenotype that remains completely/partially unexplained despite extensive sequencing of known genes are not infrequently seen at referral centers, suggesting a role of still unknown genetic factors. A compelling candidate is Bone Morphogenetic Protein 6 (BMP6), which acts as a major activator of the BMP-SMAD signaling pathway, ultimately leading to the upregulation of hepcidin gene transcription. A recent seminal study by French authors has described three heterozygous missense mutations in BMP6 associated with mild to moderate late-onset iron overload (IO). Using an updated next-generation sequencing (NGS)-based genetic test in IO patients negative for the classical HFE p.Cys282Tyr mutation, we found three BMP6 heterozygous missense mutations in four patients from three different families. One mutation (p.Leu96Pro) has already been described and proven to be functional. The other two (p.Glu112Gln, p.Arg257His) were novel, and both were located in the pro-peptide domain known to be crucial for appropriate BMP6 processing and secretion. In silico modeling also showed results consistent with their pathogenetic role. The patients' clinical phenotypes were similar to that of other patients with BMP6-related IO recently described. Our results independently add further evidence to the role of BMP6 mutations as likely contributing factors to late-onset moderate IO unrelated to mutations in the established five HH genes.

Identification of novel mutations in hemochromatosis genes by targeted next generation sequencing in Italian patients with unexplained iron overload.

Hereditary hemochromatosis, one of the commonest genetic disorder in Caucasians, is mainly associated to homozygosity for the C282Y mutation in the HFE gene, which is highly prevalent (allele frequency up to near 10% in Northern Europe) and easily detectable through a widely available "first level" molecular test. However, in certain geographical regions like the Mediterranean area, up to 30% of patients with a HH phenotype has a negative or non-diagnostic (i.e. simple heterozygosity) test, because of a known heterogeneity involving at least four other genes (HAMP, HJV, TFR2, and SLC40A1). Mutations in such genes are generally rare/private, making the diagnosis of atypical HH essentially a matter of exclusion in clinical practice (from here the term of "non-HFE" HH), unless cumbersome traditional sequencing is applied. We developed a Next Generation Sequencing (NGS)-based test targeting the five HH genes, and applied it to patients with clinically relevant iron overload (IO) and a non-diagnostic first level genetic test. We identified several mutations, some of which were novel (i.e. HFE W163X, HAMP R59X, and TFR2 D555N) and allowed molecular reclassification of "non-HFE" HH clinical diagnosis, particularly in some highly selected IO patients without concurring acquired risk factors. This NGS-based "second level" genetic test may represent a useful tool for molecular diagnosis of HH in patients in whom HH phenotype remains unexplained after the search of common HFE mutations.

Association of hepatitis C virus with insulin resistance: evidences from animal studies and clinical studies.

CONTEXT: HCV infection is strongly associated with development of insulin resistance and type-2 diabetes, however molecular mechanism of these associations is not known. The aim of this review was to conduct a comprehensive literature search to understand the nature of the association between hepatitis C virus (HCV) infection and insulin resistance (IR). We also explored the role of HCV core protein and NS5a in modulating the course of the insulin-signaling pathway. EVIDENCE ACQUISITIONS: We searched Directory of Open Access Journals (DOAJ) Google Scholar, Pubmed (NLM), LISTA (EBSCO), Web of Science (TS and PakMediNet). RESULTS: Emerging evidence suggests an association between HCV infection and carotid/coronary vascular disease. IR appears to be a dominant underlying cause of accelerated atherosclerosis in patients with chronic hepatitis C (CHC). HCV can induce IR directly through the stimulation of SOCS3 and PPA2, and both of these molecules have been shown to inhibit interferon-α signaling. Improvement of insulin sensitivity may increase the response rate to antiviral treatment and prevent IR complications, including vascular diseases. The results of several clinical trials that have used insulin sensitizers (metformin and PPAR-γ agonists) have been inconclusive. CONCLUSIONS: Beside the association between HCV and IR, the published data also have showed the possible association of HCV core and NS5A protein with IR.

Serotype and genotype analysis of dengue virus by sequencing followed by phylogenetic analysis using samples from three mini outbreaks-2007-2009 in Pakistan.

BACKGROUND: Since the first reported outbreak of dengue hemorrhagic fever in Pakistan, several mini outbreaks have erupted in the region. Dengue virus serotype 3 (DEN-3) was first documented in 2005 outbreak in Karachi. Reports show that serotype 3 is prevalent in Lahore since 2008. Serotype 2 (DEN-2) is the major circulating serotype in Pakistan as it is documented since 1994. We have conducted a detailed study of three outbreaks of dengue virus infection that occurred in years 2007, 2008 and 2009 in Lahore by using molecular techniques such as PCR and nucleotide sequencing of the C-prM gene junction of Dengue virus. RESULTS: Through the analysis of 114 serum samples collected over the period of three years (2007-2009), total 20 patients were found to be infected with dengue virus. In year 2007, four were positive for serotype 2 and one sample was positive for serotype DEN-3. In 2008, five samples had concurrent infection with serotypes DEN-2 and DEN-3 while three samples were infected only with serotype DEN-2. In year 2009, one sample had concurrent infection with serotypes DEN-2 and DEN-3 while six were positive for serotype DEN-2 only. CONCLUSIONS: Our study showed that serotype DEN-2 was dominant in positive samples of dengue virus infection collected during the period of three years (2007-2009). The other serotype present was serotype DEN-3. Genotypes of serotype DEN-2 and serotype DEN-3 were subtype IV and subtype III, respectively.

Characterization of hepatitis C Virus genotype 3a hypervariable region 1 in patients achieved rapid virological response to alpha interferon and ribavirin combination therapy.

BACKGROUND: Hepatitis C virus roots a chronic liver disease. Currently approved treatment strategy includes administration of alpha interferon and ribavirin combined therapy for 24-48 weeks. One of the predictor of sustained virological response is an early virological response to treatment characterized as rapid response. Hyper variable region 1 (HVR1) of E2 protein is responsible for viral entry and acts as a target for neutralizing antibodies. Any mutation in this region would effect virus interaction with target cell and viral persistence. METHODS: Thirty one clones of six pre-treatment samples subjected to combination therapy were investigated. Three of the patients were rapid responders (R1, R2 and R3) and two were breakthrough responders (BT1 and BT2). Envelope 2 gene was amplified, cloned and sequenced. Amino acid substitution, frequency, composition and antigenic properties of HVR 1 of E2 protein were studied. RESULTS: In both rapid responders (R.R) (14 amino acid sites) and breakthrough responders (BT.R) (13 amino acid sites) half of the amino acid sites were either conserved or resistant to any physiochemical change due to amino acid substitution. It also indicated that average composition of hydrophilic and basic amino acids were comparatively lower in rapid responders than other samples affecting probable interaction of virus with target cells. A central non antigenic region was constant among the breakthrough responders but differed in length significantly among rapid responders reflecting the adaptive nature of HVR1 to the immune response. CONCLUSIONS: We observed that although HVR1is quite variable region in HCV 3a patients responding differently to treatment it still maintains its physiochemical properties for its proper functioning and viability.

A situational analysis of HIV and AIDS in Pakistan.

HIV (Human immunodeficiency virus) transmission has been reduced by protected sex and screening of blood products and other body fluids in the developed countries. It has been reported that Pakistan is at high risk of HIV/AIDS infection but presently the prevalence rate is considerably low. The number of reported cases of HIV/AIDS in Pakistan has been continuously increasing since 1987. By 2010 the total number of registered cases has reached to 6000 and this figure is on the rise with the passage of time. Some serious strategies must be implemented to control this deadly disease.

An overview of treatment response rates to various anti-viral drugs in Pakistani hepatitis B virus infected patients.

Hepatitis B virus (HBV) is one of the leading health problem with up to 350 million affected people worldwide including 4.5 million only in Pakistan. It has mortality rate of 0.5 to 1.2 million per year worldwide. Pakistan lies in the endemic region with 3-5% HBV carrier rate in the country. The present article reviews the literature on the treatment response of HBV prevalent in Pakistani population. The average treatment response of Lamivudine and interferon-α is 25.81% and 47.95%, respectively. Peg-Interferon was shown to be not effective against the HBV/HCV (hepatitis C virus)/HDV (hepatitis Delta virus) co-infection. The present study reveals that interferon-α is the most effective therapy available for HBV infection prevalent in Pakistani population. Genotype C & D are the most common HBV genotypes in Pakistan and are associated with increased severity and less response to interferon therapy. This poses a great challenge for physicians and researchers and further studies are needed to describe the outcome of the current therapies recommended against HBV infection in Pakistani population.

Hepatitis C treatment: current and future perspectives.

Hepatitis C virus (HCV) is a member of Flaviviridae family and one of the major causes of liver disease. There are about 175 million HCV infected patients worldwide that constitute 3% of world's population. The main route of HCV transmission is parental however 90% intravenous drug users are at highest risk. Standard interferon and ribavirin remained a gold standard of chronic HCV treatment having 38-43% sustained virological response rates. Currently the standard therapy for HCV is pegylated interferon (PEG-INF) with ribavirin. This therapy achieves 50% sustained virological response (SVR) for genotype 1 and 80% for genotype 2 & 3. As pegylated interferon is expensive, standard interferon is still the main therapy for HCV treatment in under developed countries. On the other hand, studies showed that pegylated IFN and RBV therapy has severe side effects like hematological complications. Herbal medicines (laccase, proanthocyandin, Rhodiola kirilowii) are also being in use as a natural and alternative way for treatment of HCV but there is not a single significant report documented yet. Best SVR indicators are genotype 3 and 2, < 0.2 million IU/mL pretreatment viral load, rapid virological response (RVR) rate and age <40 years. New therapeutic approaches are under study like interferon related systems, modified forms of ribavirin, internal ribosome entry site (HCV IRES) inhibitors, NS3 and NS5a inhibitors, novel immunomodulators and specifically targeted anti-viral therapy for hepatitis C compounds. More remedial therapies include caspase inhibitors, anti-fibrotic agents, antibody treatment and vaccines.

Mutations in the E2-PePHD region of hepatitis C virus genotype-3a and correlation with response to interferon and ribavirin combination therapy in Pakistani patients.

Hepatitis C is a major health problem affecting more than 200 million individuals in the world. Current treatment regimen consisting of interferon alpha and ribavirin does not always succeed in eliminating the virus completely from patient's body. One of the mechanisms by which virus evades the antiviral effect of interferon alpha involves protein kinase (PKR) eukaryotic initiation factor 2 alpha (eIF2a) phosphorylation homology domain (PePHD). This domain in genotype 1 strains is reportedly homologous to PKR and its target eIF2a. By binding to PKR, PePHD inhibits its activity and therefore cause virus to evade antiviral activity of interferon (IFN). Many studies have correlated substitutions in this domain to the treatment response and lead to inconclusive results. Some studies suggested that substitutions favor response while others emphasized that no correlation exists. In the present study we therefore compared sequences of PePHD domain of thirty one variants of six hepatitis C virus patients of genotype 3. Three of our HCV 3a infected patients showed rapid virological response to interferon alpha and ribavirin combination therapy whereas the remaining three had breakthrough to the same combination therapy. It is found that PePHD domain is not entirely conserved and has substitutions in some isolates irrespective of the treatment response. However substitution of glutamine (Q) with Leucine (L) in one of the breakthrough responders made it more identical to HCV genotype 1a. These substitutions in the breakthrough responders also tended to increase average hydrophilic activity thus making binding of PePHD to PKR and inhibition of PKR more favorable.