Etiopathogenesis of sacroiliitis: implications for assessment and management.

The sacroiliac joints connect the base of the sacrum to the ilium. When inflamed, they are suspected to cause low back pain. Inflammation of the sacroiliac joints is called sacroiliitis. The severity of the pain varies and depends on the degree of inflammation. Sacroiliitis is a hallmark of seronegative spondyloarthropathies. The presence or absence of chronic sacroiliitis is an important clue in the diagnosis of low back pain. This article aims to provide a concise overview of the anatomy, physiology, and molecular biology of sacroiliitis to aid clinicians in the assessment and management of sacroiliitis. For this narrative review, we evaluated articles in English published before August 2019 in PubMed. Then, we selected articles related to the painful manifestations of the sacroiliac joint. From the retrieved articles, we found that chronic sacroiliitis may be caused by various forms of spondyloarthritis, such as ankylosing spondyloarthritis. Sacroiliitis can also be associated with inflammatory bowel disease, Crohn's disease, gout, tuberculosis, brucellosis, and osteoarthritis, indicating common underlying etiological factors. The pathophysiology of sacroiliitis is complex and may involve internal, environmental, immunological, and genetic factors. Finally, genetic factors may also play a central role in progression of the disease. Knowing the genetic pre-disposition for sacroiliitis can be useful for diagnosis and for formulating treatment regimens, and may lead to a substantial reduction in disease severity and duration and to improved patient performance.

Molecular Aspects of Regional Pain Syndrome.

The purpose of this review is to summarize the pathophysiology of complex regional pain syndrome (CRPS), the underlying molecular mechanisms, and potential treatment options for its management. CRPS is a multifactorial pain condition. CRPS is characterized by prolonged or excessive pain and changes in skin color and temperature, and/or swelling in the affected area, and is generally caused by stimuli that lead to tissue damage. An inflammatory response involving various cytokines and autoantibodies is generated in response to acute trauma/stress. Chronic phase pathophysiology is more complex, involving the central and peripheral nervous systems. Various genetic factors involved in the chronicity of pain have been identified in CRPS patients. As with other diseases of complex pathology, CRPS is difficult to treat and no single treatment regimen is the same for two patients. Stimulation of the vagus nerve is a promising technique being tested for different gastrointestinal and inflammatory diseases. CRPS is more frequent in individuals of 61-70 years of age with a female to male ratio of 3 : 1. Menopause, migraine, osteoporosis, and asthma all represent risk factors for CRPS and in smokers the prognosis appears to be more severe. The pathophysiological mechanisms underlying CRPS involve both inflammatory and neurological pathways. Understanding the molecular basis of CRPS is important for its diagnosis, management, and treatment. For instance, vagal nerve stimulation might have the potential for treating CRPS through the cholinergic anti-inflammatory pathway.

Co-expression of HIF-1α, MDR1 and LAPTM4B in peripheral blood of solid tumors.

The hypoxic tumor microenvironment is the major contributor of chemotherapy resistance in solid tumors. One of the key regulators of hypoxic responses within the cell is the hypoxia inducible factor-1α (HIF-1α) that is involved in transcription of genes promoting cell survival and chemotherapy resistance. Multidrug resistance gene-1 (MDR1) and Lysosome-associated protein transmembrane 4B-35 (LAPTM4B-35) are among those notable players which augment their responses to cellular hypoxia. MDR1 is the hypoxia responsive gene involved in multidrug resistance phenotype while LAPTM4B-35 is involved in chemotherapy resistance by stabilizing HIF-1α and overexpressing MDR1. Overexpression of HIF-1α, MDR1 and LAPTM4B has been associated with poor disease outcome in many cancers when studied individually at tissue level. However, accessibility of the tissues following the course of chemotherapy for ascertaining chemotherapy resistance is difficult and sometimes not clinically feasible. Therefore, indication of hypoxic biomarkers in patient's blood can significantly alter the clinical outcome. Hence there is a need to identify a blood based marker to understand the disease progression. In the current study the expression of hypoxia associated chemotherapy resistance genes were studied in the peripheral blood lymphocytes of solid tumor patients and any potential correlation with disease progression were explored. The expression of HIF-1α, MDR1 and LAPTM4B was studied in blood of 72 breast, 42 ovarian, 32 colon and 21 prostate cancer patients through real time PCR analysis using delta cycle threshold method. The statistical scrutiny was executed through Fisher's Exact test and the Spearman correlation method. There was 12-13 fold increased in expression of HIF-1α, two fold increased in MDR1 and 13-14 fold increased in LAPTM4B mRNA level in peripheral blood of breast, ovarian, prostate and colon cancer patients. In the current study there was an association of HIF-1α, MDR1 and LAPTM4B expression with advanced tumor stage, metastasis and chemotherapy treated group in breast, ovarian, prostate and colon cancer patients. The Spearman analysis also revealed a positive linear association among HIF-1α, MDR1 and LAPTM4B in all the studied cancer patients. The elevated expression of HIF-1α, MDR1 and LAPTM4B in peripheral blood of solid tumor patients can be a predictor of metastasis, disease progression and treatment response in these cancers. However, larger studies are needed to further strengthen their role as a potential biomarker for cancer prognosis.

Prevalence of EBV, HPV and MMTV in Pakistani breast cancer patients: A possible etiological role of viruses in breast cancer.

BACKGROUND: Breast cancer being a multifactorial disease, the role of infectious agent in development of disease is of great interest. The high incidence of breast cancer around the world has woken the interest in a viral etiology of breast cancer. Despite decades of research, no etiologic factor(s) for human breast cancer has been known and the quest for a contributing cause has all but been abandoned during the past years. Recent investigations have linked breast cancer to viral infections, such as Epstein-Barr virus (EBV), Human papillomavirus (HPV) and mouse mammary tumor virus. AIM: To investigate the possible association of EBV, HPV and MMTV infection with breast cancer development and progression. METHODS: Screening of isolated genomic DNA from FFPE breast cancer tissue biopsies (n=250) using standard polymerase chain reaction and correlation of virus prevalence with BC disease outcomes using statistical analysis software (SPSS 16.0). RESULTS: Our findings suggest the prevalence of EBV (24.4%), HPV (18.1%) and MMTV (29.3%), while coinfection of HPV and EBV was detected in 9.2% (23/250), co infection of HPV and MMTV in 3.2% (8/250) and coinfection of EBV and MMTV in 6% (15/250) of breast cancer samples. No virus was detected in 59.5% of the breast cancer samples. Mono infection of EBV and HPV do not statistically co-relate with the clinico-pathological outcomes of breast cancer disease, though MMTV infection does co-relate with age and grade of breast cancer disease. In our study, the prevalence of coinfection of HPV, EBV and MMTV in Pakistani breast cancer patients is rare, still there is a possibility of synergistic carcinogenic effect of different viruses in the development of breast cancer disease. CONCLUSION: The significant percentage of virus prevalence shows potential role in breast cancer development. However, this study provides substantial but not conclusive evidence for the involvement of viruses in BC disease development and progressiveness.

Molecular detection and characterization of respiratory syncytial virus B genotypes circulating in Pakistani children.

Respiratory syncytial virus (RSV) is the major cause of acute lower respiratory tract infections in young children, but very little is known about its epidemiology and circulating genotypes in Pakistan. This study analyzed the epidemiological and molecular characteristics of RSV B genotypes in Pakistani children below 5years with acute respiratory tract infections (ARIs) during three consecutive winter seasons from 2010 to 2013. A total of 1941 samples were analyzed for RSV infection by real time PCR and 24% (472/1941) samples were found positive out of which 22.3% (105/472) were sub-typed as RSV-B. The frequency of outpatient cases was higher (62.5%; 295/472) as compared to hospitalized patients (37.5%; 177/472). Patient ages ranged from 2month to 5years with a mean age of 1.48±1.2 (years) and a median age of 1year. Children below one year made up the highest percentage of enrolled subjects and male to female ratio of RSVB positive cases was nearly equivalent (1:1.1). The most common clinical symptoms were cough (96%), fever (80%) and sore throat (50%). All Pak RSVB strains ascribed to the BA genotype showing 91.9-97.1% and 86.2-95.3% homology at the nucleotide and amino acid levels respectively in comparison to BA prototype strain. On phylogenetic analysis, three genotypes of Pakistan RSV B viruses were observed; BA-9 and BA-10 which have been reported previously from other regions, and a third novel genotype assigned as BA-13 which formed a distinct cluster with protein length of 319 AA and showed 9-11 unique AA substitutions. All the RSV B isolates had two potential N-glycosylation sites in HVR2 of G protein and with heavy O-glycosylation of serine and threonine residues (G scores of 0.5-0.7). This study highlights the diversity of RSVB viruses and the significance of RSV as a dominant viral etiologic agent of pediatric ARI. It also emphasizes the need for continued molecular surveillance for early detection of prevalent and newly emerging genotypes to understand epidemiology of RSV infections in various regions of Pakistan.

Respiratory syncytial virus and influenza are the key viral pathogens in children <2 years hospitalized with bronchiolitis and pneumonia in Islamabad Pakistan.

Pneumonia remains a leading cause of morbidity and mortality in developing countries. Comprehensive surveillance data are needed to review the prevention and control strategies. We conducted active surveillance of acute lower respiratory infections among children aged <2 years hospitalized at two hospitals of Islamabad, Pakistan. Viral etiology was determined using real-time PCR on respiratory specimens collected during March 2011-April 2012. The overall mean age was 7.83 ± 5.25 months while no statistical difference between age or sex distribution of patients with positive and negative viral etiology (p > 0.05). The average weight of the study group was 6.1 ± 2.25 kg. ≥1 viral pathogens were detected in 75% cases. Major respiratory viruses included RSV-A: 44%, RSV-B: 23%, Influenza-A: 24.5%, Influenza-B: 7%, Adenovirus: 8.4% and HmPV: 5.2%. A single, dual or multiple viral pathogens were detected in 43%, 27% and 5.2% patients respectively. Common symptoms were cough (95%), apnoea (84%), fever (78%), wheeze (64.5%), nasal congestion (55%) and rhinorrhea (48%). Among the RSV positive cases, 2-6 months age group had highest detection rate for RSV-A (30%, n = 21/69) and RSV-B (20%, n = 14/69) while patients infected with Influenza-A were in 2.1-6 months age group (61%, 23/38). Statistically significant difference was observed between RSV-positive and negative cases for nutrition status (p = 0.001), cigarette/wood smoke exposure (p = 0.001) and concomitant clinical findings. Most patients had successful outcome on combination therapy with bronchodilators, inhaled steroids and antibiotics. Our findings underscore high burden of ALRI in Pakistan. Interventions targeting viral pathogens coupled with improved diagnostic approaches are critical for better prevention and control.

Unraveling the molecular mechanism governing the tissue specific expression of IFNλR1.

The functional receptor for type III interferons (IFNs) is a heterodimer of IFNLR1 and IL10R2. IFNLR1 is expressed in a highly tissue specific manner, with epithelial and liver tissue as the prime expressing tissues in humans. However, knowledge about the molecular pathways responsible for regulating the expression of IFNLR1 is yet unknown. In this study, various bioinformatics tools were used to predict the scores of signal peptides of IFNλR1 and IFNαR1, which was considered as an important difference in the expression of both receptors or participation in regulating the IFNLR1 gene. In silico study revealed that the signal peptide of IFNαR1 had more potential than the signal peptide of IFNλR1 but changing the signal peptide of wild type IFNλR1 with the signal peptide of IFNαR1 in wet lab had barely shown any differences. Selective expression of IFNλR1 was considered to be a plus point towards the targeted anti-viral activity of IFNλs but artificial control on its expression will surely make IFNλs a better drug with enhanced activity. The results of this study may help us in contributing some understanding towards the mechanisms involved in the selective expression of IFNLR1 and exceptionalities involved.

Identification of essential regulatory elements responsible for the explicit expression of IL-28Rα and their effect on critical SNPs using in-Silico methods.

IL-28Rα and IL10Rß collectively construct a fully functional hetero-dimeric receptor for type III interferons (IFNs). IL-28Rα is the private chain for type III IFNs since their involvement in any other pathway has not been reported yet and they are highly expressed in response to certain viral attack or cancers. IL-28Rα is specific in their expression pattern and it expresses within few cell types only. The regulatory mechanisms governing the expression of IL-28Rα at the molecular level are not completely known yet and need to be scrutinized at primary levels. In the present study, various in-silico techniques were applied and it was observed that AP1-2, STAT 1-6, P-53, LyF-1 (lymphoid transcription factor), c-Jun, PU.1, CREB (cAMP response element-binding), PLAG (pleotropic adenoma gene), MYOD (myoblast determination protein 1), NOFL and KLFS as transcription factors that are selected with preference. Interestingly AP-2, c-Jun, LyF-1, STAT, NF-Y and P53 have also been reported in literature recently as some of the key regulatory elements as well. Based on the fact that interlinking between different interferon stimulation genes (ISGs) is also not very clear and induction of one type of interferon can affect the efficacy of the other, we found that IFN-λ4 induction can increase the expression of IL-28Rα, similar to IFN-λ3 but contrary to type I IFNs, which has either no effect on the expression of IL-28Rα or can down regulate its expression at higher concentrations (data not published).

Deciphering the mystery of hepatitis B virus receptors: A historical perspective.

Hepatitis B virus is one of the major reasons of viral hepatitis with an estimated 350 million infected patients worldwide. Although, the virus was discovered and cloned more than three decades ago, its entry mechanism has still been in investigation. Numerous potential candidates have been proposed and investigated rigorously to reveal HBV entry mechanism and to unveil the first door of viral entry to hepatocytes. This review provides a short account of role of receptors for entry of HBV into hepatocytes. The viral preS1 region of large surface protein is involved in the attachment of HBV to hepatocytes. The putative attachment site of HBV is located at amino acids 21-47 of preS1. So far, several proteins have been proposed to interact with these different regions of the preS1 domain which includes human immunoglobulin A receptor, glyceraldehyde-3-phosphate dehydrogenase, interleukin-6, a 31-kDa protein, HBV binding factor, asialoglycoprotein receptor, nascent polypeptide-associated complex α polypeptide, lipoprotein lipase, hepatocyte-associated heparan sulfate proteoglycans, glucose-regulated protein 75. However, none of them have appeared to be generally accepted as a true receptor for the virus until recently when sodium taurocholate cotransporting polypeptide identified as HBV entry receptor. Current review provides scientific historical perspective of various candidates known to be interacting with preS1 of HBV for their possible role in viral entry.

Detection and identification of mouse mammary tumor virus-like DNA sequences in blood and breast tissues of breast cancer patients.

Mouse mammary tumor virus (MMTV) is a well-known cause of mammary tumors in mice transmitted as endogenous proviruses or exogenously as infectious virions. The hypothesis that a retrovirus homologous to MMTV is involved in human breast cancers has resulted in renewed interest in the etiology of human breast cancer. Therefore, the detection of MMTV-like exogenous sequences in 30-40 % of invasive breast cancer has increased attention towards this hypothesis. To detect the prevalence of MMTV in Pakistani population, 666-bp-long MMTV envelop and 630-bp LTR sequences were amplified from breast cancer patient samples (tissue biopsies and peripheral blood) using mouse with mammary tumor as control. MMTV-like virus env and LTR DNA sequences were detected in 20 and 26 % of breast tumor samples, respectively, from the total of 80 breast cancer patients' blood and tissue samples. No significant association was observed between age, grade of disease, and lymph node involvement with the prevalence of MMTV-like sequences. Our data add to the growing number of studies implicating MMTV-like virus in human breast cancer, but still clear causal association of MMTV to breast cancer remains to be reputable.

Molecular characterization of circulating respiratory syncytial virus (RSV) genotypes in Gilgit Baltistan Province of Pakistan during 2011-2012 winter season.

Respiratory syncytial virus (RSV) is the major cause of acute lower respiratory tract infections in young children, but very little is known about its epidemiology and circulating genotypes in Pakistan. This study analyzed the epidemiological and molecular characteristics of RSV genotypes detected in Pakistani children less than 2 years of age with acute respiratory tract infections (ARIs) in a tertiary care hospital in Gilgit Baltistan (GB) province during 2011-12 winter season. RSV was detected in 75 out of 105 children presenting with acute respiratory infection. Male infants between 2-6 months age made up the highest percentage of RSV positive cases. Epidemiological factors such as pre-maturity, mean weight, clinical features and diagnosis when compared between RSV positive and negative groups were found to be statistically insignificant. Phylogenetic analysis classified all 75 of the RSV strains into 71 strains of subgroups A and 4 strains of subgroup B, respectively. Strains belonging to subgroups A and B were further subdivided into NA1/GA2 and BA, respectively. The nucleotide and deduced amino acid sequence identities were relatively high among these strains (>90%). Both RSV-A and RSV-B isolates had two potential N-glycosylation sites in HVR2 of G protein and with heavy O-glycosylation of serine and threonine residues (G scores of 0.5-0.7). This report highlights the significance of RSV as a dominant viral etiologic agent of pediatric ARIs, and need for continued molecular epidemiological surveys for early detection of prevalent strains and newly emerging genotypes to understand epidemiology of RSV infections in various regions of Pakistan.

A unique BCR-ABL1 transcript with the insertion of intronic sequence from BCR and ABL1 genes in a patient with Philadelphia-positive chronic myeloid leukemia: a case study.

The BCR-ABL1 fusion gene results from a reciprocal translocation rearrangement, t(9;22)(q34;q11.2), and is a hallmark of chronic myeloid leukemia (CML). The breakpoint on chromosome 9 is mostly 5' to ABL1 exon 2, whereas on chromosome 22, the breakpoint can occur in various regions involving the major breakpoint cluster region (M-bcr) in CML and the minor breakpoint cluster region (m-bcr) in acute lymphoblastic leukemia. Described here is a rare case of Philadelphia-positive CML with intronic splice sites. This atypical BCR-ABL1 transcript was detected along with a classic e13a2 transcript, using reverse transcription polymerase chain reaction (RT-PCR). Nucleotide sequence analysis revealed a joining of BCR intron 13 with ABL1 intron 1a. Both transcripts were detected when the patient was on hydroxyurea treatment; with imatinib mesylate therapy, the atypical transcript disappeared. To our knowledge, this is the first report of BCR-ABL1 transcript with breakpoint occurring within both BCR and ABL1 introns and fusion of intronic sequences from both BCR and ABL1 genes.