Determination of cytomegalovirus prevalence and glycoprotein B genotypes among ulcerative colitis patients in ahvaz, iran

Significance of Cytomegalovirus gB Genotypes in Adult Patients Undergoing Hematopoietic Stem Cell Transplantation: Insights from a Single-Centre Investigation

INTRODUCTION

Cytomegalovirus (CMV) infection is a major clinical issue after allogeneic hematopoietic stem cell transplantation (HSCT). The CMV envelope glycoproteins are key in viral pathogenesis; the glycoprotein B (gB) encoded by the UL55 gene might be an important determinant of viral virulence and disease severity marker in patients treated with allogeneic HSCT. Our aim was to investigate the molecular diversity of CMV gB and inquire into the associations between UL55 gene variations and clinical manifestations in adult patients treated with allogeneic HSCT.

RESULTS

The most prevalent genotypes were gB1 and gB4 (11/27, 40.7%). Patients with genotype gB1 infection had earlier platelet engraftment (p < 0.033) and less frequent minimal/measurable residual disease post HSCT than those without this genotype. Patients with gB4 glycoprotein infection had a significantly lower CD4+/CD8+ ratio at D90 (p < 0.026). Interestingly, patients with gB5 glycoprotein infection had shorter overall survival from base condition diagnosis (p < 0.042), as well as shorter overall survival after HSCT (p < 0.036). Acute GvHD was noted more frequently in those with mixed-genotype infection (p = 0.047).

MATERIAL AND METHODS

The study included fifty-nine adult patients treated with allogeneic HSCT. Peripheral venous blood was sampled typically per week, with detection of CMV performed by quantitative real-time PCR. Multiplex nested PCR was used to determine specific gB genotypes, which were then statistically compared vis-à-vis specific clinical variables.

CONCLUSIONS

Our study points to variations in the viral UL55 locus imparting both beneficial (earlier platelet engraftment, less frequent MRD post HSCT) and adverse effects (shorter overall survival, more frequent acute GvHD, less frequent 100% chimerism at day 90) to the transplanted host. Comprehensive molecular investigations are necessary to validate this apparent duality, as the potential benefits of CMV could perhaps be utilized for the benefit of the patient in the future.

Congenital cytomegalovirus infection in newborns suspected of congenital rubella syndrome in Iran: a cross-sectional study

BACKGROUND

Following rubella virus control, the most important cause of congenital infections is human cytomegalovirus (HCMV). Congenital CMV (cCMV) may happen both in primary and non-primary maternal infections. The present study aimed to screen cCMV in symptomatic newborns suspected of congenital rubella syndrome (CRS) in Iran.

METHODS

Out of 1629 collected infants' serum samples suspected of CRS but negative for rubella IgM, 524 samples were selected regarding cCMV complications. These samples were divided into two age groups: 1- one month and younger, 2- older than 1 month up to one year. Anti-HCMV IgM detection was performed on these serums. Then HCMV IgG avidity assay and HCMV DNA detection were carried out on all samples with positive and borderline results in IgM detection.

RESULTS

Herein, 3.67% of symptomatic infants aged one month and younger had positive and borderline HCMV IgM, 12.5% of which had a low avidity index (AI). HCMV IgM detection rate among symptomatic infants older than one month to one year was 14.5%. Identified genotypes in this study were gB-1(63.63%), gB2 (18.18%), and gB3 (18.18%), respectively.

CONCLUSIONS

This comprehensive study was performed on serum samples of symptomatic infants clinically suspected of cCMV from all over Iran. There was a good correlation between serology findings and PCR.

Human papillomaviruses and bladder cancer risk: first report in south of Iran

Information regarding the possible carcinogenicity of human papillomaviruses (HPVs) in bladder tissue might pave the way for the prevention of bladder cancer through improving HPV vaccination of the at-risk population. To address this, this study was conducted to detect HPVs in bladder cancer tissues in the South of Iran. Bladder biopsy samples of 181 patients with bladder cancer were included in this study. The detection of HPVs was performed by nested PCR assay, targeting the L1 region of the genome, and sequencing. HPV was detected in 0.55% of the bladder cancer samples, while the non-cancerous bladder samples were negative for HPV. HPV genotype 6 was detected in this study. The HPV-positive patient was a 55-year-old man with papillary urothelial neoplasms of low malignant in stage Ta-T1. This patient was resident of Dayer city. Overall, HPV prevalence among patients with bladder cancer was not statistically associated with place of residency, gender, age, stage, and grade of the tumor (P value > 0.05). The presence of HPV is extremely rare in bladder cancer biopsy specimens in the south of Iran. Therefore, the results of our study rule out the possible role of HPVs in the etiology of bladder cancer. Due to the increasing air pollution in this region and high-risk jobs, and habits such as cigarette smoking and hookah smoking, the role of these factors alongside genetic factors seems more prominent than the role of HPVs in causing bladder cancer in the south of Iran.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-023-00819-w.

BK and JC polyomaviruses and risk of urothelial bladder carcinoma: a preliminary study in the northern shores of Persian Gulf, Iran

Background

Bladder cancer is a challenging public health concern in South of Iran because of its high prevalence and the related medical expenses. Although the exact etiology of bladder cancer remains unknown, given the cell transforming ability and oncogenic potential of the members of Polyomaviridae families, this study was conducted to evaluate the magnitude of BK polyomavirus (BKPyV) and John Cunningham polyomavirus (JCPyV) among patients with bladder cancer residents in the northern shores of the Persian Gulf, South of Iran.

Methods

Totally 211 patients with bladder cancer were enrolled in this study. Bladder biopsy samples of these patients and patients with interstitial cystitis as well as autoptic samples of healthy bladder were tested for detection of BKPyV and JCPyV by semi-nested PCR–RFLP followed by sequencing.

Results

BKPyV and JCPyV were detected in 1.7% and 6.1% of bladder cancer samples, respectively. These samples were infected with JCPyV genotypes 2, 3 and 6 and BKPyV genotypes I and IV. BKPyV and JCPyV coinfection was detected in 2 samples. Moreover, one of the healthy bladder samples was positive for BKPyV, and one of the interstitial cystitis samples was positive for JCPyV. Although the majority of infected patients were in the age group 70–79 years, male, residents in Tangestan, stage Ta–T1, and low-grade and high-grade papillary urothelial carcinoma, the prevalence of BKPyV and JCPyV among patients with bladder cancer was not statistically associated with age, gender, place of residency, and stage and grade of the tumor.

Conclusion

Despite identifying BKPyV and JCPyV in a number of bladder cancer biopsy specimens and the high prevalence of bladder cancer among people resident in South of Iran, it is suggested that these viruses are unlikely to be effective causative factors in bladder carcinogenesis in this region. Therefore, environmental risk factors and genetic backgrounds may have a more prominent role than human polyomaviruses in the development of bladder cancer in South of Iran.

Molecular Detection and Genotyping of Human Cytomegalovirus in Kidney Transplant Recipients under Ganciclovir Prophylaxis in Iran

INTRODUCTION

Human cytomegalovirus (HCMV) infection is one of the most common viral complications in kidney transplant recipients. Although there are effective treatments strategies for the HCMV infection, this infection is still one of the causes of kidney transplant rejection.

METHODS

A total of 246 kidney transplant recipients participated in this cross-sectional study. Viral DNA was extracted from these plasma samples, and the presence of HCMV genome was determined by semi-nested PCR with specific primers for the HCMV B glycoprotein gene. Sanger sequencing analyses were carried out to determine HCMV genotypes, and the Mega x software was used for nucleotide alignment and construction of a phylogenetic tree.

RESULTS

HCMV DNA was detected in 11 (4.47%) recipients. According to the phylogenetic analysis, HCMV gB3 was 50% among kidney transplant recipients, followed by gB4 30% and gB1 20%; however, the gB2 genotype was not detected.

CONCLUSIONS

This study demonstrated that the HCMV infection in our patients is relatively low because all transplant recipients received appropriate prophylaxis, thereby antiviral prophylaxis is recommended for all patients at risk of HCMV infection after kidney transplantation. Also, gB3 was the most predominant genotype among our kidney transplant recipients that was related to the higher rate of prevalence of severe HCMV infections. Moreover, an elevated serum creatinine level was detected in patients at the time of detection of HCMV infection.

Molecular evaluation of hepatitis B virus infection and predominant mutations of pre-core, basal core promoter and S regions in an Iranian population with type 2 diabetes mellitus: a case-control study

Background

This study was designed to evaluate the prevalence, genotypic patterns, and predominant mutations of hepatitis B virus (HBV) infection among diabetic patients.

Methods

Serum samples were obtained from 733 patients with type 2 diabetes mellitus and 782 non-diabetic controls. The presence of HBsAg and HBcAb was determined by ELISA. Nested PCR, targeting S and pre-core regions of the HBV genome, followed by sequencing was carried out to determine HBV genotypes and predominant mutations in the S, basal core promoter (BCP), and pre-core regions of the HBV genome.

Results

Of 733 diabetic patients, 94 cases (12.82%) were positive for HBcAb, 28 cases (3.82%) were positive for HBsAg, and 19 cases (2.59%) had HBV-DNA with genotype D, sub-genotype D1/D3 and subtype ayw2. An occult HBV infection was found in one of the HBV DNA-positive samples, which was positive for HBcAb but negative for HBsAg. P120T/G145R, G1896A/G1899A, and A1762T/G1764T were the most frequent point substitution mutations detected in the S, pre-core, and BCP regions of the HBV genome, respectively. P120T and G145R mutations were associated with low levels or undetectable levels of HBsAg in serum. Therefore, routine tests based on HBsAg detection cannot detect HBsAg-negative infected patients.

Conclusions

Relatively high prevalence of HBV infection was found in diabetic patients, while all of the HBV-infected patients were unaware of their infection. Therefore, screening for HBV infection should be included in the management program of diabetes for timely diagnosis and treatment of infected but asymptomatic patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07528-7.

Prevalence, genotype distribution and mutations of hepatitis B virus and the associated risk factors among pregnant women residing in the northern shores of Persian Gulf, Iran

Background

Considering perinatal transmission and the high rate of chronic hepatitis B virus (HBV) infection in infants, diagnosis of HBV infection during pregnancy and timely interventions are of great importance. Therefore, this study was performed to investigate the prevalence and genotype distribution of HBV infection and the associated risk factors among pregnant women in the northern shores of the Persian Gulf, South of Iran.

Methods

Serum samples of 1425 pregnant women were tested for the presence of HBsAg and HBcAb by ELISA (HBsAg one—Version ULTRA and HBc Ab ELISA kits, DIA.PRO, Milan, Italy). The seropositive samples were tested for the presence of HBV DNA by nested PCR, targeting S, X, pre-core (pre-C), and basal core promoter (BCP) regions of the HBV genome. The amplified fragments were sequenced by Sanger dideoxy sequencing technology to evaluate the genotype distribution and mutations of HBV infection by using the MEGA 7 software. The HBV seropositive pregnant women were tested for HCV and HIV coinfections by ELISA (HCV Ab and HIV Ab/Ag ELISA kits, DIA.PRO, Milan, Italy).

Results

Of 1425 participants, 15 pregnant women (1.05%, 95% CI: 0.64%-1.73%) were positive for HBsAg, 41 women (2.88%, 95% CI: 2.10%-3.88%) were positive for HBcAb, and 5 women (0.35%, 95% CI: 0.15% –0.82%) had HBV viremia with genotype D, sub-genotype D3 and subtype ayw2. One of the viremic samples was positive for HBcAb but negative for HBsAg, which is indicative of an occult HBV infection. HBsAg seroprevalence was higher among pregnant women aged 20 to 29 years, women in the third trimester of pregnancy, residents of Khormuj city, Afghan immigrants, illiterate women, and pregnant women with a history of tattoo and HBV vaccination. The highest rate of HBcAb seroprevalence was observed in residents of Borazjan city, Turk ethnicity, the age group >39 years, and those women with more parities and a history of abortion. Nevertheless, HBV seroprevalence among pregnant women was not statistically associated with these variables. In contrast, HBcAb seropositivity was significantly associated with the history of tattoo (P = 0.018). According to mutations analyses, seven amino acid substitutions in the HBsAg, one point mutation in the pre-C region, and five points mutations in the BCP region were detected. Besides, the BCP mutations caused amino acid substitutions in the X protein. Of note, the conversion of Ala → Val at amino acid 168 (A168V) and Thr → Pro at amino acid 127 (T127P) were detected in HBsAg of the occult HBV strain.

Conclusion

These results indicate a relatively low prevalence of HBV infection among pregnant women in the South of Iran, while tattooing is a risk factor for exposure to HBV infection. Moreover, all of the HBV-positive pregnant women were asymptomatic and unaware of their infection. Therefore, routine screening for HBV markers during pregnancy, appropriate treatment of HBV-infected women, and HBV vaccination are recommended to decrease mother-to-child transmission of HBV.

Molecular Evaluation of Human Parvovirus B19 Infection and Associated Risk Factors among Pregnant Women in Bushehr Province, Southern Iran

Given the importance of human parvovirus B19 infection during pregnancy and the potential risks to the fetus, this study was designed to determine the prevalence, genotypic pattern, and risk factors of parvovirus B19 infection among a population-based sample of pregnant women in Bushehr Province, southern Iran. A total of 824 pregnant women were enrolled in this study. Serum samples were screened for the detection of anti-parvovirus B19 IgM and IgG by ELISA. The molecular evaluation was performed by nested polymerase chain reaction, targeting the non-structural protein 1-viral protein 1 unique region of the genome, and sequencing. Of 824 pregnant women, 330 (40.1%) were positive for anti-parvovirus B19 IgG and 50 women (6.1%) had anti-parvovirus B19 IgM. A greater rate of anti-parvovirus B19 IgG seroprevalence was observed in women older than 39 years, in Afghan immigrants, and in those women with more parities. Anti-parvovirus B19 IgM seroprevalence decreased with increasing gestational age and was significantly greater among women in the first trimester of pregnancy and among residents of the city of Borazjan. Moreover, 0.73% of the pregnant women had parvovirus B19 viremia with genotype 1 and subtype 1a. Parvovirus B19 DNA was detected in the samples collected in late autumn and winter, which is a rainy season associated with temperate climes in southern Iran. According to the results of this study, approximately 60% of pregnant women in this region are serologically negative and susceptible to parvovirus B19 infection. Therefore, assessment for maternal parvovirus B19 infection is important and should be considered as part of the fetal-maternal health policy in Iran.

Molecular identification and clinical characteristics of mumps virus and human herpesviruses associated with aseptic meningitis in South of Iran

Viral infections are the major etiological agent of aseptic meningitis; though, limited data exist on the prevalence and molecular epidemiology of viral pathogens responsible for the occurrence of aseptic meningitis in Iran. Therefore, this study aimed to elucidate the prevalence and clinical features of mumps virus and human herpesviruses associated with aseptic meningitis in the South of Iran. A total of 73 patients with aseptic meningitis were enrolled in this study. Cerebral spinal fluid (CSF) samples were tested for detection of HSV, CMV, VZV and mumps virus using nested PCR assay. Mumps virus, HSV-1 and VZV were found in 4 (5.5%), 4 (5.5%) and 3 (4.1%) of the CSF samples, respectively. The highest rates of mumps virus and HSV infections were observed in infants less than one year, and VZV was more prevalent in patients under 5 years of age. The majority of mumps virus and VZV infections were found among male patients, while HSV was more prevalent among female patients. The highest incidence of aseptic meningitis associated with mumps virus was observed in summer, while HSV and VZV were more prevalent during spring. Headache was the most common symptom in mumps meningitis. About HSV and VZV, the most predominant clinical symptom was fever. The results of this study indicate the importance of molecular assay in the diagnosis of etiological agents of aseptic meningitis. Prompt detection of viral pathogens provides a better chance of managing viral meningitis in health care settings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-021-00718-y.

Common Polymorphisms in the Glycoproteins of Human Cytomegalovirus and Associated Strain-Specific Immunity

Human cytomegalovirus (HCMV), one of the most prevalent viruses across the globe, is a common cause of morbidity and mortality for immunocompromised individuals. Recent clinical observations have demonstrated that mixed strain infections are common and may lead to more severe disease progression. This clinical observation illustrates the complexity of the HCMV genome and emphasizes the importance of taking a population-level view of genotypic evolution. Here we review frequently sampled polymorphisms in the glycoproteins of HCMV, comparing the variable regions, and summarizing their corresponding geographic distributions observed to date. The related strain-specific immunity, including neutralization activity and antigen-specific cellular immunity, is also discussed. Given that these glycoproteins are common targets for vaccine design and anti-viral therapies, this observed genetic variation represents an important resource for future efforts to combat HCMV infections.

Molecular detection of E. coli and Vibrio cholerae in ballast water of commercial ships: a primary study along the Persian Gulf

PURPOSE

Ballast water is one of the most important ways for the transfer of aquatic organisms such as Escherichia coli (E. coli) and Vibrio cholerae. The aim of this study was to investigate Mdh gene of E. coli and the OmpW gene of Vibrio cholerae bacteria by PCR technique in the ballast water of commercial ships entering Bushehr port along the Persian Gulf.

METHODS

In this study, 34 samples of ballast water entered Bushehr port were studied by using culture and PCR methods to determine Mdh gene of E. coli and OmpW gene of Vibrio cholerae. Genomic DNA of bacterial strains was extracted and PCR was performed by using specific primers of E. coli and Vibrio cholerae.

RESULTS

The specific Mdh gene of E. coli was detected in 4 ballast water samples and the positive samples were analyzed by antisera methods for E. coli O157:H7. Results of antisera showed that there were 3 positive samples of O157:H7 serotype. The results of the PCR technique showed that the OmpW gene of Vibrio cholerae was negative for all positive culture samples.

CONCLUSIONS

Further studies are highly recommended to monitor other aquatic organisms in ballast water to protect the marine environment.

Molecular epidemiology of enteroviruses and predominance of echovirus 30 in an Iranian population with aseptic meningitis

Human enteroviruses are the most prevalent causes of aseptic meningitis worldwide. However, despite such predominancy, defining the enteroviral etiology of aseptic meningitis remains a diagnostic dilemma for the clinician in Iran. Therefore, this study was conducted to characterize the prevalence and clinical significance of enteroviral aseptic meningitis as well as the predominant enterovirus serotypes among patients with aseptic meningitis in the South of Iran.Cerebrospinal fluid (CSF) specimens were obtained from 73 patients with aseptic meningitis (52.1% males and 47.9% females), ages ranging from 1 month to 88 years. Following the extraction of nucleic acid, the detection of enteroviruses was performed by RT-PCR, targeting the 5' untranslated region of the genome, and sequencing. Enteroviruses were found in 46.6% of samples (34/73). The most predominant serotype was echovirus 30, followed by coxsackievirus B5 and poliovirus type 1 Sabin strain. The enterovirus infections were more prevalent among female patients (58.8%) and those below 5 years of age (52.9%). Although enterovirus infections were observed throughout the year, the infections were more prevalent during autumn with fever as the predominant clinical symptom. The outcomes revealed that enteroviruses are significant causes of aseptic meningitis in the South of Iran, while suspected cases of aseptic meningitis are usually monitored by bacterial culture and biochemical testing of CSF samples. Therefore, the etiology remains unknown in most cases. Molecular detection of viral pathogens should be included as a common approach in the screening of patients with aseptic meningitis to prevent unnecessary treatment and to improve clinical management.

Cytomegalovirus and Inflammatory Bowel Diseases (IBD) with a Special Focus on the Link with Ulcerative Colitis (UC)

Cytomegalovirus (CMV) infects approximately 40% of adults in France and persists lifelong as a latent agent in different organs, including gut. A close relationship is observed between inflammation that favors viral expression and viral replication that exacerbates inflammation. In this context, CMV colitis may impact the prognosis of patients suffering from inflammatory bowel diseases (IBDs), and notably those with ulcerative colitis (UC). In UC, the mucosal inflammation and T helper cell (T_H) 2 cytokines, together with immunomodulatory drugs used for controlling flare-ups, favor viral reactivation within the gut, which, in turn, increases mucosal inflammation, impairs corticoid and immunosuppressor efficacy (the probability of steroid resistance is multiplied by more than 20 in the case of CMV colitis), and enhances the risk for colectomy. This review emphasizes the virological tools that are recommended for exploring CMV colitis during inflammatory bowel diseases (IBD) and underlines the interest of using ganciclovir for treating flare-ups associated to CMV colitis in UC patients.

Distribution of cytomegalovirus genotypes among ulcerative colitis patients in Okinawa, Japan

BACKGROUND/AIMS

To determine the prevalence of glycoprotein B (gB), glycoprotein N (gN), and glycoprotein H (gH) genotypes of human cytomegalovirus (HCMV) superimposed on ulcerative colitis (UC) patients in Japan.

METHODS

Four archived stool samples and 7-archived extracted DNA from stool samples of 11 UC patients with positive multiplex polymerase chain reaction (PCR) results for HCMV were used UL55 gene encoding gB, UL73 gene encoding gN, and UL75 gene encoding gH were identified by PCR. Genotypes of gB and glycoprotein N were determined by sequencing.

RESULTS

Among 11 samples, 8 samples were amplified through PCR. gB, gN, and gH genotypes were successfully detected in 3 of 8 (37.5%), 4 of 8 (50%), and 8 of 8 (100%), respectively. The distribution of gB and gN genotypes analyzed through phylogenetic analysis were as follows: gB1 (2/3, 66.7%), gB3 (1/3, 33.3%), gN3a (2/4, 50%), and gN3b (2/4, 50%). Other gB genotypes (gB2 and gB4) and gN genotypes (gN1, gN2, and gN4) were not detected in this study. Out of successfully amplified 8 samples of gH genotype, gH1 and gH2 were distributed in 12.5% and 75% samples, respectively. Only 1 sample revealed mixed infection of gH genotype. The distribution of gH1 and gH2 differed significantly (1:6, P<0.05) in UC patients. The distribution of single gH genotype also revealed significant difference in UC patients who were treated with immunosuppressive drug (P<0.05).

CONCLUSIONS

In this study, gB1, gN3, and gH2 gene were determined as the most frequently observed genotypes in UC patients, which suggest that there might be an association between these genotypes of HCMV and UC.

Prevalence and Genotype Distribution of Hepatitis C Virus Infection among Patients with Type 2 Diabetes Mellitus

OBJECTIVE

This study was conducted to determine the prevalence and genotype distribution of hepatitis C virus (HCV) infection among patients with type 2 diabetes mellitus (DM).

SUBJECTS AND METHODS

We included 556 consecutive patients with confirmed type 2 DM attending the Diabetic Clinic of the Bushehr University of Medical Sciences and 733 nondiabetic subjects as controls. Serum levels of fasting blood sugar (FBS), alanine transaminase (ALT), aspartate transaminase (AST), total cholesterol (TCH), and triglycerides (TG) were measured by enzymatic colorimetric methods, and the presence of anti-HCV antibodies was determined by enzyme-linked immunosorbent assay. Semi-nested reverse transcriptase-polymerase chain reaction (RT-PCR) followed by sequencing was performed on all anti-HCV-seropositive samples. Data were analyzed using the Statistical Package for the Social Sciences 17, and descriptive statistics, χ2 test, Fisher exact test, and the Student t test were used for analysis.

RESULTS

The seroprevalence of HCV in the diabetic patients was 1.98% (11/556), which was higher than HCV prevalence among the nondiabetic controls (4/733, 0.54%) (p = 0.032). No significant differences in ALT, AST, FBS, TG, and TCH levels were found between the HCV-seropositive and HCV-seronegative diabetic patients, although HCV-seropositive diabetic patients tended to have higher ALT, AST, and TCH levels, but lower TG and FBS levels than HCV-seronegative patients. In logistic regression analysis, only AST levels were significantly associated with HCV seropositivity among diabetic patients. The AST level of 41-80 IU/L was the only significant predictive variable for HCV seropositivity in the diabetic patients (odds ratio, 4.89; 95% CI: 1.06-22.49; p = 0.041). Of the 11 HCV-seropositive diabetic patients, 10 (91%) had HCV viremia with genotype 3a.

CONCLUSION

Patients with type 2 DM had a higher prevalence of HCV infection than controls, and HCV seropositivity was independent of biochemical parameters.

Is cytomegalovirus infection related to inflammatory bowel disease, especially steroid-resistant inflammatory bowel disease? A meta-analysis

BACKGROUND

Human cytomegalovirus (HCMV) infection has been associated with inflammatory bowel disease (IBD). Numerous studies have been conducted to analyze the association between HCMV infection and risk of IBD and steroid-resistant IBD, but no clear consensus had been reached.

OBJECTIVES

The aim of this study was to confirm this relationship precisely by doing a systematic review and meta-analysis.

STUDY DESIGN

We identified relevant studies through a search of PubMed and Embase. Studies were eligible for inclusion if they 1) evaluated the association between HCMV infection and IBD disease; 2) evaluated the association between HCMV infection and steroid-resistant IBD disease; 3) were case-control studies or nested case-control studies; 4) provided the numbers (or percentage) of positivity for HCMV infection in cases and controls, respectively. Data were extracted and analyzed independently by two investigators.

RESULTS AND CONCLUSION

A total of 18 studies including 1,168 patients and 951 health groups was identified, and HCMV infection was distinctly confirmed as a risk factor for the occurrence and development of IBD. When involving 17 studies including 1,306 IBD patients, a total of 52.9% of patients in the cytomegalovirus (CMV)-positive groups were observed to have steroid resistance, compared with 30.2% of patients in the CMV-negative groups. There was a significant difference in the risk of steroid resistance between people exposed to HCMV infection and those not exposed HCMV infection in IBD patients. This meta-analysis suggested that HCMV infection is associated with an increased risk for IBD and steroid-resistant IBD.