HBV reactivation after fludarabine chemotherapy identified on investigation of suspected transfusion-transmitted Hepatitis B virus

Frequency of viral infections in adolescent and adult in-patient Ethiopians with acute leukemia at presentation to a tertiary care teaching hospital: a cross-sectional study

BACKGROUND

Leukemic patients are prone to infectious agents such as viruses due to dysregulated immune system resulting from infiltration of the bone marrow by malignant cells, chronic stimulation, reactivation of some viruses and viral pathogenicity as well as rarely from acquisition of a new infections leading to severe complications. However, the prevalence of these infections has not been systematically documented in resource-limited settings such as Ethiopia.

OBJECTIVE

To determine the prevalence of HBV, HCV, and HIV among adult and adolescent in-patients with acute leukemia before the administration of chemotherapy, at the Tikur Anbessa Specialized Hospital (TASH) in Addis Ababa, Ethiopia.

METHODS

A cross sectional study was conducted on 176 adult and adolescent inpatient Ethiopians, who were diagnosed with acute leukemia from April 2019 to June 2021. Socio-demographic characteristics and relevant clinical data were collected. Peripheral blood samples were collected and tested for HBV, HIV, and HCV using Enzyme-Linked Immunosorbent Assay (ELISA) and real-time PCR. Chi-square tests were used to assess associations between variables.

RESULTS

Of the 176 patients, 109(62%) were males. The median age was 25[IQR,18-35] yr, with a range from 13 to 76 year. The prevalence of HBV (positivity for HBsAg plus HBV DNA), HCV and HIV was 21.6%, 1.7%, and 1.7%, respectively. HBsAg was positive in 19 cases (10.8%). Among 157 HBsAg negative patients, 52(33.1%) were positive for Anti-HBcAg; of these seropositive cases, 47.5% were positive for HBV DNA. Most DNA positive, HBsAg negative cases (79.0%) had DNA concentrations below 200 IU/ml indicating true occult HBV infection (OBI). Of the 176 cases, 122 had a history of blood transfusions, but no statistically significant association was found between HBV infection and blood product transfusion history (P = 0.963).

CONCLUSIONS

The prevalence of HBV, HIV and HCV in patients with acute leukemia was similar to the national prevalence level of these infections. Given the HBsAg positivity and the high prevalence of occult hepatitis B infection in our study, these patients may be at increased risk for chemotherapy related hepatitis flares. Hence, clinicians caring these patients are strongly advised to screen their patients for HBV and also for HIV and HCV infections routinely.

Outcome of nucleos(t)ide analog intervention in patients with preventive or on-demand therapy for hepatitis B virus reactivation

Preventive or on-demand nucleos(t)ide analog (NA) therapy can prevent severe hepatitis related to hepatitis B virus reactivation (HBV-R). However, it is unclear if NA can be safely stopped in such patients after cytotoxic therapies or during immunosuppressive therapies. We retrospectively evaluated 133 patients who initiated NA therapy between 2007 and 2018. A total of 103 patients were positive for HBV surface antigen (HBsAg) at baseline, and NA therapy was started before cytotoxic or immunosuppressive therapy (preventive group). Thirty patients with resolved HBV infection were treated with NA therapy after HBV reactivation (on-demand group). Virological relapse was defined as a serum HBV DNA level >20 IU/ml. NA therapy was stopped in 12 (12%) patients (preventive group), and in 16 (53%) patients (on-demand group). After the cessation of NA therapy, the cumulative rates of relapse were 36% and 39% at 12 and 24 months, respectively. High levels of HBsAg both at baseline and at the cessation of NA therapy were related to the occurrence of relapse. Relapse did not occur in patients with HBsAg levels <20 IU/ml (preventive group). HBV relapse occurred in five (33%) patients in the on-demand group. Relapse occurred only in anti-HBs-negative patients at the cessation of NA therapy. There were no cases of hepatitis flare after the cessation of NA therapy. HBsAg predicted HBV relapse after the cessation of NA therapy in HBsAg-positive patients. Anti-HBs could be a predictive marker for NA therapy cessation in patients with resolved HBV.

Prevalence of occult HBV infection in Western countries

Due to a lack of standardized tests, it is difficult to obtain prevalence data and define the real impact of occult HBV infection (OBI) in Western countries. The present review article addresses the prevalence of OBI, defined as presence of hepatitis B virus (HBV) DNA in liver tissue or plasma in HBsAg-negative subjects, in Western countries. This varies in different studies according to the different methodologies used (based on serology vs virology), to the sample analyzed for the diagnosis (liver tissue vs plasma), to the different populations studied, to the different geographical variations in the HBV spread, to the host characteristics (age, gender, risk factors for acquiring HBV infection) and to the presence of other parenteral infections (hepatitis C virus and/or human immunodeficiency virus [HIV] infections). Considering the different liver diseases analyzed, that is in patients with cryptogenic cirrhosis or advanced liver fibrosis, the prevalence of OBI ranges 4% to 38%. Considering the different populations studied, in the case of parenteral blood exposure it is about 45%, in patients with chronic hepatitis C it is estimated at about 52%, in HIV-infected patients it ranges from 0% to 45%, in blood donors from 0% to 22.7% and in hemodialysis patients it ranges from 0% to 54%. In conclusion, OBI is a virological entity to be considered when performing the patient's evaluation for immunosuppressive diseases, liver pathologies, or for blood transfusions. Knowing the prevalence and clinical impact of OBI will allow better patient management.

Multiple HBV transfusion transmissions from undetected occult infections: revising the minimal infectious dose

OBJECTIVE

HBV infection by blood components is currently prevented in most developed countries by combining sensitive HBV surface antigen (HBsAg) assays, nucleic acid testing (NAT) and in a few of them antibodies against the HBV core antigen (anti-HBc) screening. HBV transmissions by blood components from three repeat donors tested negative for HBsAg and HBV DNA with a highly sensitive screening test (limit of detection (LOD): 3.4 IU/mL) were investigated.

DESIGN

30 of the 47 recipients of components produced from these three donors were examined. Transfusion transmission was confirmed by phylogenetic analysis of viral sequences obtained from recipients and donors following viral particle concentration.

RESULTS

9 of 31 (29%) recipients were infected: 7 infections were related to 200 mL of fresh frozen plasma and 2 infections to red blood cells containing 20 mL plasma. Transfusion transmission was confirmed by >99% identity of donor/recipient sequences in five cases, probable in three and possible in one. HBV active infection remained unsuspected for 24-57 months in three recipients. Five non-infected recipients carried anti-HBs when transfused. Six patients transfused with platelet concentrates treated with a pathogen reduction method were not infected. These data enabled to revise previous estimate of the minimal infectious dose from approximately 100 to 16 copies (or 3 IU) of HBV DNA.

CONCLUSIONS

HBV transfusion transmission from occult HBV infection carrying extremely low viral loads is related to plasma volume transfused and possibly prevented by anti-HBs. HBV blood safety could be further improved by either anti-HBc screening, HBV DNA NAT with a LOD of 0.8 copies/mL (0.15 IU/mL) or pathogen reduction of blood components.

Late effects of treatment in survivors of childhood cancers: A single-centre experience

BACKGROUND & OBJECTIVES

With improved survival of childhood cancer patients, the number of long-term cancer survivors is increasing. Some studies have assessed the long-term morbidity after childhood cancer treatment in the developing countries. This study was conducted to assess the spectrum of late effects of cancer treatment in paediatric cancer survivors.

METHODS

Evaluation of the first 300 patients who completed five years of follow up in the after treatment completion clinic was done. Details of primary diagnosis, treatment received and current clinical status were noted. The spectrum of late effects was ascertained by appropriate investigations.

RESULTS

Haematological malignancies comprised 25 per cent of total cases. Most common primary diagnosis comprised acute lymphoblastic leukaemia, retinoblastoma and Hodgkin's lymphoma. The median age at evaluation and follow up was 14 and 8.5 yr, respectively. Twenty three per cent (69) of the survivors had a minimal disability (growth retardation or underweight), 13 per cent (39) had moderate disabilities needing medical attention (hepatitis B surface antigen positive, myocardial dysfunction, azoospermia and hypothyroidism), while two per cent had major/life-threatening disabilities (mental retardation, liver disease and mortality). Eleven patients relapsed on follow up, of those five patients expired. Two second malignancies were recorded during the period of follow up.

INTERPRETATION & CONCLUSIONS

Late effects were of concern; however, severe disability (Grade 3-5) was seen in only two per cent survivors. Lifelong follow up of childhood cancer survivors is required to assess cancer-related morbidity, occurrence of a secondary neoplasm, to facilitate timely diagnosis and to implement remedial or preventive interventions to optimize health outcomes. Awareness towards the existence of late effects of cancer therapy is required among parents, patients and health professionals.

Case report: a fatal case of disseminated adenovirus infection in a non-transplant adult haematology patient

BACKGROUND

We report a fatal case of disseminated adenovirus infection in a non-transplant haematology adult patient with chronic lymphocytic leukaemia who had completed combination chemoimmunotherapy a few months before developing respiratory symptoms. In such non-transplant patients, monitoring for adenovirus in the blood is not routine. However, with adenoviruses, when there is a more peripheral (i.e. non-blood) site of infection such as the chest, serial adenovirus monitoring in blood for the duration of that illness may be warranted.

CASE PRESENTATION

This case started with an initial bacterial chest infection that responded to treatment, followed by an adenovirus pneumonitis that disseminated to his blood a week later with levels of up to 92 million adenovirus DNA copies/ml. Despite prompt treatment with cidofovir, his respiratory function continued to deteriorate over the next two weeks and he was moved to intensive care. Intravenous immunoglobulin and ribavirin were subsequently added to his treatment. However, he died soon after this with a final adenovirus load of 20 million copies/ml in his blood.

CONCLUSIONS

We recommend that even in non-transplant haematology patients, where such patients present with an acute respiratory adenovirus infection, teams should consider checking the blood for adenovirus to check for signs of disseminated infection. The earlier this can be tested, the earlier treatment can be initiated (if adenovirus positive), which may produce more successful clinical outcomes.

High risk of occult hepatitis B virus infection in leukemia patients from China

In this study, we assessed the prevalence of overt and occult hepatitis B virus (HBV) infection among leukemia patients. Among 256 leukemia patients and 377 fracture patients (control group), we found that the hepatitis B surface-antigen-positive rate was greater in leukemia patients than in the controls (odds ratio, 2.08; p = 0.01). Moreover, the prevalence of occult HBV infection was higher in leukemia patients than in the controls (10.5 % vs. 2.9 %; odds ratio, 3.92; p < 0.001). The HBV genotype distribution differed significantly between the leukemia and chronic hepatitis B or control groups (p < 0.001 and 0.01, respectively); specifically, genotype C was primarily observed in occult HBV infection patients with leukemia. The stop codon mutation rate or amino acid substitutions in the major hydrophilic region did not differ between the groups. Thus, the prevalence of occult hepatitis B is higher in leukemia patients, and the HBV genotype distribution differs between patients with leukemia and chronic hepatitis B virus infection.

Screening for hepatitis B in patients with lymphoma

Chronic hepatitis B virus (HBV) infection can be reactivated during lymphoma chemotherapy, specifically with rituximab. In 2008, the Centers for Disease Control and Prevention and, in 2010, the American Society of Clinical Oncology made recommendations that anyone who received cytotoxic or immunosuppressive therapy should be tested for serologic markers of HBV infection. In our study, we wanted to determine the screening rates for HBV infection at our institution and if simply adding a checkbox onto the rituximab order would improve HBV screening. We performed a retrospective chart review of two cohorts of lymphoma patients at Scott & White Health Clinic. Cohort 1 included patients from 1993 to 2008. Cohort 2 included patients who received rituximab after an institutionwide protocol (rituximab order checkbox) was initiated in 2011. A total of 452 patients treated for lymphoma were reviewed. Only 15 of the 404 Cohort 1 patients received HBV screening (3.7%; 95% confidence interval, 2.1%-6.1%). Screening rates were statistically higher if baseline liver laboratory values were elevated (P < 0.0001). HBV was also checked more frequently if patients' liver function tests became elevated while on chemotherapy, 85.7% (12/14). Of the 48 patients in Cohort 2, 33 patients (68.7%) received HBV screening. No patients in either cohort had a positive HBV surface antigen or developed reactivation of HBV during chemotherapy. The addition of a checkbox on the rituximab order form significantly increased our screening for HBV infection in lymphoma patients initiating chemotherapy.

Infectivity of blood products from donors with occult hepatitis B virus infection

BACKGROUND

Occult hepatitis B virus (HBV) infection (OBI) is identified in 1:1000 to 1:50,000 European blood donations. This study intended to determine the infectivity of blood products from OBI donors.

STUDY DESIGN AND METHODS

Recipients of previous donations from OBI donors were investigated through lookback (systematic retrieval of recipients) or traceback (triggered by clinical cases). Serologic and genomic studies were undertaken on consenting donors and recipients. Multiple variables potentially affecting infectivity were examined.

RESULTS

A total of 45 of 105 (42.9%) donor-recipients pairs carried antibodies to HBV core (anti-HBc) as evidence of previous HBV infection. Subtracting 15% of anti-HBc population background, the adjusted transmission rate was 28%. Anti-HBc prevalence increased to 28 of 44 (63.8%) in unvaccinated recipients receiving anti-HBs-negative OBI blood products. In contrast, four of 26 (15.4%) recipients of anti-HBs-positive products were anti-HBc positive. Transmission with anti-HBs-negative products depended on volume of plasma transfused (85%-100% with 200 mL of fresh frozen plasma [FFP], 51% with 50 mL in platelet concentrates [PCs], and 24% with 20 mL in red blood cells [RBCs], p < 0.0001 FFP vs. RBCs). The 50% minimum infectious dose of OBI HBV DNA was estimated at 1049 (117-3441) copies. Donor and recipient strains sequence homology of at least 99% confirmed transfusion-transmitted infection in 10 cases and excluded it in one case.

CONCLUSION

Blood products from donors with OBI carry a high risk of HBV transmission by transfusion. This risk is dependent on presence of anti-HBs and viral dose. This may justify safety measures such as anti-HBc and HBV nucleic acid test screening depending on epidemiology.

Hepatitis B virus in transfusion medicine: still a problem?

Hepatitis B virus (HBV) has probably evolved with humans for nearly 35,000 years. HBV diversified into 9 genotypes (A-I) presenting specific features directing epidemiology, clinical expression and testing. Genotypes E and C are more infectious and carry higher risk of chronicity and cancer. HBsAg blood screening implemented 40 years ago enormously decreased the risk of transfusion transmission but the remaining risk requires extremely sensitive nucleic acid testing (NAT) to be removed. Limitations of the host immune system, the impact of immunodeficiency and the mechanisms utilised for viral persistence were recently identified. HBV replication produces excess HBsAg and infectious and defective viral particles but screening assays for HBsAg or viral particles alone do not allow fully efficient detection, making necessary screening for both. The host immune system fails to completely control the virus that escapes and persists unrecognized at very low levels or as immuno-selected variants. Variants may not be identified by assays, explaining false negative results. Specific mutations may affect post-transcriptional mechanisms including HBV RNA splicing. Asymptomatic HBV infected blood donors are at risk of long-term complications through mechanisms to be understood for appropriate counselling. Infectivity of occult HBV infection (OBI) by transfusion appears low, anti-HBc (anti-core antigen) only being more infectious than anti-HBs (anti-S protein) positive units.

Challenges in hepatitis B detection among blood donors

PURPOSE OF REVIEW

The availability of hepatitis B virus (HBV) nucleic acid testing (NAT) for donor blood screening led to its implementation in low prevalence and high prevalence countries. Genomic detection was a substantial addition to HBV surface protein (HBsAg) screening by detecting window period infections and 'occult' HBV infections (OBIs), characterized by undetectable HBsAg, low viral load and presence of serological markers (anti-HBc and/or anti-HBs). OBIs are the result of multiple, poorly understood mechanisms including incomplete immune control mutations of the HBsAg antigenic determinants; abnormal expression of S gene; and inhibition of genome transcription. Infectivity for the recipient is high for window period blood and relatively low for OBIs.

RECENT FINDINGS

The number of cases identified by NAT ranges between 1 : 1000 and 1 : 50 000, depending on epidemiology and assay sensitivity whether NAT is implemented in individual donations or pools of samples. OBI donors are generally older than 45 years except in Africa, carry very low viral load (median 11-25  IU/ml) and have normal alanine transaminase levels. Cases carrying anti-HBc alone are more infectious than those with low level of anti-HBs. Evidence of HBsAg escape mutants that are undetected by commercial assays has been published. Inhibition of HBsAg mRNA production and export are potential mechanisms of OBI occurrence.

SUMMARY

HBV blood safety is improved by NAT for HBV DNA when applied to individual donations. Until the sensitivity of NAT is improved, both this method and HBsAg screening are needed to eliminate potentially infectious blood donations. Occult HBV characterization clarifies new facets of HBV natural history.

Significant background rates of HBV and HCV infections in patients and risks of blood transfusion from donors with low anti-HBc titres or high anti-HBc titres with high anti-HBs titres in Japan: a prospective, individual NAT study of transfusion-transmitted HBV, HCV and HIV infections

BACKGROUND

The Japanese Red Cross (JRC) conducted a prospective study to evaluate the frequency of transfusion-transmitted HBV, HCV and HIV infections to assess the risk of transfusion of blood components routinely supplied to hospitals.

STUDY DESIGN AND METHODS

Post-transfusion specimens from patients at eight medical institutes were examined for evidence of infection with HBV (2139 cases), HCV (2091) and HIV (2040) using individual nucleic acid amplification testing (NAT). If these specimens were reactive, pre-transfusion specimens were also examined for the virus concerned by individual NAT. In the event that the pre-transfusion specimen was non-reactive, then all repository specimens from implicated donors were tested for the viruses by individual donation NAT. In addition, a further study was carried out to evaluate the risk of transfusion of components from donors with low anti-HBc titres or high anti-HBc with high anti-HBs titres.

RESULTS

Transfusion-transmitted HCV and HIV infections were not observed. One case of post-transfusion HBV infection was identified (rate, 0·0004675; 95% CI for the risk of transmission, 1 in 451-41,841). The background rates of HBV, HCV and HIV infections in patients prior to transfusion were 3·4% (72/2139), 7·2% (150/2091) and 0% (0/2040), respectively. Sixty-four anti-HBc- and/or anti-HBs-reactive blood components were transfused to 52 patients non-reactive for anti-HBc or anti-HBs before and after transfusion (rate, 0; 95% CI for the risk of transmission, <1 in 22).

CONCLUSION

This study demonstrated that the current criteria employed by JRC have a low risk, but the background rates of HBV and HCV infections in Japanese patients are significant.

Antiviral treatment in patients with hepatitis B virus infection receiving chemotherapy

Reactivation of hepatitis B virus (HBV) is a frequent complication of chemotherapy in patients with HBV infection. Reactivation is characterized by increased levels of serum HBV DNA, abnormal liver function and hepatic failure. HBV reactivation inevitably leads to disruption of chemotherapy and severe clinical results in some cases. Nucleoside analogues play an important role in preventing and reducing the risk for HBV reactivation and HBV-associated morbidity and mortality. This paper gives a systematic review of the definition, mechanism and causes of HBV reactivation and summarizes the principles and problems for antiviral treatment in patients with HBV reactivation. It is strongly recommended that all patients should be screened for HBV serum markers before chemotherapy and preventive therapy with nucleoside analogues be given in patients with HBV. The use of potent antiviral drugs with low resistance potential and close viral monitoring during therapy are important for patients with HBV infection undergoing chemotherapy.