High prevalence of transfusion-transmitted virus infection in patients with chronic liver diseases in an endemic area of hepatitis B and C virus

Viral metagenomics in Brazilian multiply transfused patients with sickle cell disease as an indicator for blood transfusion safety

BACKGROUND AND AIM

Patients with sickle cell disease (SCD) are submitted to multiple transfusions in order to increase the oxygen capacity of the blood, decrease blood viscosity, and suppress the sickling of the cells. Multiply transfused patients with SCD represent significant risk of acquiring parenterally transmitted infections. The analysis of the virome profile of high-risk multiply transfused patients with SCD can reveal the presence of parenterally transmitted viruses and therefore be used an indirect approach for evaluation of blood transfusion safety.

MATERIALS AND METHODS

Blood samples were collected from 45 patients with SCD receiving multiple transfusions and analyzed by metagenomic analyses. The samples were assembled in pools f which were submitted to nucleic acids extraction and sequencing by Illumina NextSeq 550 equipment. For bioinformatic analysis, we used a specific in-house developed pipeline specialized in identification of emerging viruses.

RESULTS

The virome composition of SCD patients revealed the presence of commensal viruses represented by anelloviruses and Human Pegivirus-1 (HPgV-1, GB virus C). Contaminant viral sequences belonging to human lentiviruses (rev, env genes), cytomegalovirus and murine leukemia virus were also identified and are attributed to vectors used in the laboratory practice. No novel or unsuspected pathogenic viruses were identified.

CONCLUSION

This study evaluates for the first time the virome of multiply transfused patients with SCD. Exclusively genetic material of commensal viruses was annotated. Therefore, we believe that viral metagenomics applied in patients with high risk for acquiring parenterally transmitted infections can serve as a direct indicator for evaluation of transfusion safety.

Association Between TT Virus Infection and Cirrhosis in Liver Transplant Patients

BACKGROUND

Cirrhosis is one of the most severe liver complications, with multiple etiologies. The torque teno virus (TTV), also known as transfusion transmitted virus, which has a high incidence in the world population, is one of the possible increasing risk factors in patients with idiopathic fulminant hepatitis and cryptogenic cirrhosis.

OBJECTIVES

The aim of this study was to evaluate solitary and co-infection with TTV, in patients with cryptogenic and determined cause of cirrhosis.

PATIENTS AND METHODS

In this cross-sectional study, 200 liver transplant patients were consecutively recruited between years 2007 and 2011. Patients were classified, based on recognition of the etiology of cirrhosis to determined (n = 81) and cryptogenic (n = 119) patient groups. The existence of TTV infection was analyzed, using a semi-nested polymerase chain reaction method. The presence of hepatitis B virus (HBV) infective markers, including HBV DNA, hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), hepatitis B core antibody (HBcAb), and hepatitis B e antibody (HBeAb), was evaluated using qualitative polymerase chain reaction and enzyme linked immunosorbent assay protocols, respectively.

RESULTS

The TTV infection was found in 37 of 200 (18.5%) and 53 of 200 (26.5%) plasma and tissue samples of studied liver transplanted patients, respectively. The TTV genomic DNA was found in 32 (26.9%) and 28 (23.5%) of 119 liver tissue and plasma samples of transplanted patients with cryptogenic cirrhosis, respectively. The genomic DNA of TTV was also diagnosed in 21 (25.9%) and nine (11.1%) of the 81 liver tissue and plasma samples of patients with determined cirrhosis, respectively. Significant associations were found between TTV infection with HBV molecular and immunologic infective markers, in liver transplanted patients, with determined and cryptogenic cirrhosis.

CONCLUSIONS

The diagnosis of the high frequency of solitary TTV and co-infection with HBV, in both liver transplanted patients with cryptogenic and determined cirrhosis, emphasized on the importance of TTV infection in the development of cirrhosis, especially in the cases of cryptogenic ones, prompting for further studies the confirm this agent in the etiology of determined cirrhosis.

Detection and genotyping of torque teno virus (TTV) in healthy blood donors and patients infected with HBV or HCV in Qatar

Torque Teno virus (TTV) has been associated with non A-G hepatitis. The goal of this study was to estimate the infection rates and genotypic characteristics of TTV in the State of Qatar. A total of 644 blood samples representing different nationalities: (i) Qatari (118) and (ii) non-Qatari (526) nationals (mostly from Arab and South Eeast Asia countries) were tested for the presence of TTV DNA by nested PCR. The majority (573) of the blood samples belonged to healthy blood donors, whereas 54 and 53 of the blood samples belonged to patients infected with hepatitis B virus (HBV) and hepatitis C virus (HCV), respectively. The results obtained showed that the TTV infection rates in the healthy blood donors, and those infected with HBV or HCV patients were 81.4, 90.75 and 84.9%, respectively. Significant association between TTV viremia and age, or nationality was observed. Sequence analysis of PCR fragments amplified from the 5'-untranslated region (5'-UTR) of all (531) TTV positive samples showed that 65.5% (348/531) of the PCR fragment sequences were classified into main genogroup 3, followed by main genogroups 5 (24%), 2 (5.8%), and 1 (4.7%). Genogroup 4 was not detected among the our studied subjects. Phylogenetic and pairwise analyses using sequences from TTV viremic samples also showed an overall close similarity to the main genogroup 3. In conclusion, there was no significant difference in the rates of TTV detection among Qataris and non-Qataris and several genotypes, mainly genotype 3, were isolated.

Phylogenetic analysis of Torque Teno Virus genome from Pakistani isolate and incidence of co-infection among HBV/HCV infected patients

BACKGROUND

Torque Teno Virus (TTV) was the first single stranded circular DNA virus to be discovered that infects humans. Although there have been numerous reports regarding the prevalence of TTV from other countries of South Asia, there is severe lack of information regarding its prevalence in Pakistan. Thus the present study compiles the first indigenous report to comprehensively illustrate the incidence of the virus in uninfected and hepatitis infected population from Pakistan. Another aim of the study was to present the sequence of full length TTV genome from a local isolate and compare it with the already reported genome sequences from other parts of the world.

METHODS

TTV DNA was screened in the serum of 116, 100 and 40 HBV infected, HCV infected and uninfected individuals respectively. Nearly full length genome of TTV was cloned from a HBV patient. The genome sequence was subjected to in-silico analysis using CLC Workbench, ClustalW, ClustalX and TreeView. Statistical analysis was carried out in SPSS v17.0.

RESULTS

Our results report that 89.7%, 90.0% and 92.5% of HBV, HCV patients and healthy control population were positive for TTV infection. TTV genome of 3603 bp was also cloned from a local isolate and given the identity of TPK01. The TTV genome sequence mentioned in this paper is submitted in the GenBank/EMBL/DDBJ under the accession number JN980171. Phylogenetic analysis of TPK01 revealed that the Pakistani isolate has sequence similarities with genotype 23 and 22 (Genogroup 2).

CONCLUSION

The results of the current study indicate that the high frequency of TTV viremia in Pakistan conforms to the reports from other areas of the world, wherever screening of TTV DNA was performed against 5'-UTR of the genome. The high sequence diversity among TTV genome sequences and the high frequency of prevalence makes it harder to study this virus in cellular systems.

Performance of three PCR methods targeting different regions of viral genome for the detection of TTV in Non A-E hepatitis, chronic B and C hepatitis and healthy blood donors

TT virus (TTV) was suggested to be the etiologic agent for non A-E hepatitis but this could not yet be proven due to high detection rates not only in hepatitis but also in healthy persons and sensitivity differences of PCR methods employed. The aim of this study was to evaluate TTV DNA positivity in non A-E hepatitis cases, chronic HBV and HCV hepatitis cases and healthy blood donors via PCR systems that target all regions of the viral genome used for viral detection. 23 non A-E hepatitis, 28 chronic HCV, 21 chronic HBV cases and 56 healthy blood donors were included in the study and evaluated by PCR protocols that target 5′-UTR, 3′-UTR and N22 (ORF1) regions. As a result, 3′-UTR and 5′-UTR PCR had comparable detection rates that were higher than N22 PCR. Differences in detection rates among study groups were not statistically significant for any PCR method. Hepatic enzyme levels of the patients were not correlated with the presence of TTV DNA. Detection rate was significantly higher for Non A-E hepatitis group when positivity rates from all methods were combined. These results suggest an alteration of viral genotypes in Non A-E hepatitis which might be associated with pathogenesis.

Frequency of hepatitis G virus and transfusion-transmitted virus infection in type II diabetes mellitus

The hepatitis G virus (HGV) and transfusion-transmitted virus (TTV) are recently defined hepatitis viruses that the pathogenic roles in liver diseases are still not clear. It has been well known that some hepatitis virus, such as hepatitis C, might have an affinity to pancreatic islet cells. To investigate the relationship between the newly defined hepatitis viruses and diabetes mellitus (DM), we studied the prevalence of TTV and HGV in a type 2 diabetic patient population. Serum samples of 60 patients with DM and 45 healthy volunteers as control were taken. HGV RNA and TTV DNA was investigated by polymerase chain reaction. HGV was detected in none of diabetic patients (0%) and only one in control group (2.2%). However, TTV DNA was detected in 16 patients with DM (26%) and in five controls (11%). TTV was more prevalent in diabetic patients, but the difference between groups was not statistically significant (p > 0.05). These results revealed that TTV is more common in diabetic patients than in controls. At present, we don't know if this result is only a coincidence or a sign of potential association between TTV and DM. Further studies are certainly needed to elucidate a potential relationship.

Open Heart Surgery for Small Children Without Homologous Blood Transfusion by Using Remote Pump Head System

BACKGROUND

To avoid excessive hemodilution, the transfusion of a large amount of homologous blood may be required in open heart surgery for small children, which in turn, can cause a significant immunologic response.

METHODS

Cardiopulmonary bypass systems with remote pump heads were used for patients weighing 5 kg or less that were undergoing ventricular septal defect repair. The procedures took place from January 1997 to August 2002. The surgery was started with bloodless prime in 122 out of 158 (77.2%) consecutive patients. Exclusion criteria were a predicted hematocrit after the initiation of bypass of less than 15%, respiratory failure or heart failure (or both), and pulmonary vascular obstructive disease.

RESULTS

The mean age and body weight were 3.8 +/- 1.8 months and 4.3 +/- 0.5 kg, respectively. The priming volume was 181.0 +/- 32.5 (minimum: 130) mL. The hematocrit after cardiopulmonary bypass was initiated was 16.7% +/- 2.3%. Six patients required subsequent blood transfusion owing to postoperative complications that resulted in compromised hematopoiesis. In the rest, the hematocrit before discharge was 30.6% +/- 3.0%. Renal and liver function tests were maintained within the normal range. Patients were extubated at 5.6 +/- 2.8 hours after operation with proper oxygenation. Neurodevelopment was apparently normal. The Japanese psychomotor developmental scale assessment was given to patients without chromosomal abnormality between the ages of 1 and 3 years; the resulting score was 102.2 +/- 15.4 (mean = 100 for normal population).

CONCLUSIONS

Open heart surgery was achieved without blood transfusion in the selected group of small children. The use of remote pump heads reduced the overall need for blood transfusions and possibly inflammatory reactions.

Transfusional transmitted virus seroprevalence in asymptomatic HBsAg (+) hepatitis B carriers

BACKGROUND

The aim of this study was to evaluate the transfusional transmitted virus (TTV) seroprevalence in asymptomatic HBsAg (+) patients and to assess the influence of TTV on the course of these patients.

METHODS

Sixty asymptomatic HBV carriers were included and 31 healthy volunteers served as controls. Cases were followed at 6-month intervals for a total duration of 4 years.

RESULTS

In the asymptomatic carrier group, 31 patients (51.7%) had a history of surgery and 10 (16.7%) had a history of blood transfusions. TTV-DNA was detected in 45 of these patients (75%). In the control group, 12 patients (38.7%) had a history of surgery and 2 had (6.5%) a history of blood transfusions. TTV-DNA was found in 20 (64.5%) of these subjects. The incidence of TTV-DNA positivity was not significantly different between the two groups (P > 0.05).

CONCLUSION

In spite of the common occurrence of HBV and TTV, TTV-DNA was also detected in 64.5% of healthy controls. Furthermore, during 4 years of follow up, TTV had no detrimental effects on the course of asymptomatic HBV carriers. These results suggest that the hepatic injury due to TTV is insignificant in this group of patients.