Screening for adenoviruses in haematological neoplasia: High prevalence in mantle cell lymphoma.

Human adenoviruses possess oncogenic capacity which is well documented in mammalian animal models, but their possible implication in human malignancy has remained enigmatic. Following primary infection, adenoviruses can persist in a latent state in lymphocytes where the virus is apparently able to evade immune surveillance. In the present study, we have employed a broad-spectrum adenovirus polymerase chain reaction (PCR) assay to systematically screen more than 200 diagnostic specimens of different lymphoid malignancies including acute lymphocytic leukaemia (n=50), chronic lymphocytic leukaemia (n=50), various types of malignant lymphoma (n=100) and multiple myeloma (n=11) for the presence of adenoviral sequences. While most entities analysed revealed negative findings in virtually all specimens tested, adenoviral DNA was detected in 15/36 (42%) mantle cell lymphomas investigated. The most prevalent adenoviral species detected was C, and less commonly B. Adenovirus-positive findings in patients with mantle cell lymphoma were made at different sites including bone marrow (n=7), intestine (n=5), lymph nodes (n=2) and tonsillar tissue (n=1). The presence of adenoviral sequences identified by PCR was confirmed in individual cells by fluorescence in-situ hybridisation (FISH). The frequent observation of adenoviruses in mantle cell lymphoma is intriguings, and raises questions about their possible involvement in the pathogenesis of this lymphoid malignancy.

Efficacy of a carrageenan nasal spray in patients with common cold: a randomized controlled trial.

BACKGROUND: The common cold is the most widespread viral infection in humans. Iota-carrageenan has previously shown antiviral effectiveness against cold viruses in clinical trials. This study investigated the efficacy of a carrageenan-containing nasal spray on the duration of the common cold and nasal fluid viral load in adult patients. METHODS: In a randomized, double-blind, placebo-controlled trial, 211 patients suffering from early symptoms of the common cold were treated for seven days. Application was performed three times daily with either a carrageenan-supplemented nasal spray or saline solution as placebo with an overall observation period of 21 days. The primary endpoint was the duration of disease defined as the time until the last day with symptoms followed by all other days in the study period without symptoms. During the study, but prior unblinding, the definition of disease duration was adapted from the original protocol that defines disease duration as the time period of symptoms followed by 48 hours without symptoms. RESULTS: In patients showing a laboratory-confirmed cold virus infection and adherence to the protocol, alleviation of symptoms was 2.1 days faster in the carrageenan group in comparison to placebo (p = 0.037). The primary endpoint that had been prespecified but was changed before unblinding was not met. Viral titers in nasal fluids showed a significantly greater decrease in carrageenan patients in the intention-to-treat population (p = 0.024) and in the per protocol population (p = 0.018) between days 1 and 3/4. CONCLUSIONS: In adults with common cold virus infections, direct local administration of carrageenan with nasal sprays reduced the duration of cold symptoms. A significant reduction of viral load in the nasal wash fluids of patients confirmed similar findings from earlier trials in children and adults. TRIAL REGISTRATION: Current Controlled Trials ISRCTN80148028.

Lessons learned from a double-blind randomised placebo-controlled study with a iota-carrageenan nasal spray as medical device in children with acute symptoms of common cold.

BACKGROUND: Common cold is caused by a variety of respiratory viruses. The prevalence in children is high, and it potentially contributes to significant morbidity. Iota-carragenan, a polymer derived from red seaweed, has reduced viral load in nasal secretions and alleviated symptoms in adults with common cold. METHODS: We have assessed the antiviral and therapeutic activity of a nasal spray containing iota-carrageenan in children with acute symptoms of common cold. A cohort of 153 children between 1-18 years (mean age 5 years), displaying acute symptoms of common cold were randomly assigned to treatment with a nasal spray containing iota-carrageenan (0.12%) as verum or 0.9% sodium chloride solution as placebo for seven days. Symptoms of common cold were recorded and the viral load of respiratory viruses in nasal secretions was determined at two consecutive visits. RESULTS: The results of the present study showed no significant difference between the iota carrageenan and the placebo group on the mean of TSS between study days 2-7. Secondary endpoints, such as reduced time to clearance of disease (7.6 vs 9.4 days; p = 0.038), reduction of viral load (p = 0.026), and lower incidence of secondary infections with other respiratory viruses (p = 0.046) indicated beneficial effects of iota-carrageenan in this population. The treatment was safe and well tolerated, with less side effects observed in the verum group compared to placebo. CONCLUSION: In this study iota-carrageenan did not alleviate symptoms in children with acute symptoms of common cold, but significantly reduced viral load in nasal secretions that may have important implications for future studies. TRIAL REGISTRATION: ISRCTN52519535, http://www.controlled-trials.com/ISRCTN52519535/

Prevalence and clinical course of viral upper respiratory tract infections in immunocompromised pediatric patients with malignancies or after hematopoietic stem cell transplantation.

BACKGROUND: Respiratory tract infections (RTI) in immunosuppressed pediatric patients with malignancies or after hematopoietic stem cell transplantation (HSCT) are associated with significant morbidity and mortality. Prospective data on the incidence and clinical role of infections by respiratory viruses in this population have been lacking. METHODS: In this prospective study, 191 children between 0 and 18 years of age were investigated by real-time polymerase chain reaction for the presence of 8 common respiratory virus types in transnasal aspirations. The study included 110 children with leukemia, lymphoma, or solid tumors (subgroup 1); 31 children after HSCT (subgroup 2); and 50 immunocompetent control patients. RESULTS: In comparison with the control group, immunocompromised children showed a significantly higher incidence of positive virus tests (subgroup 1: 53%; subgroup 2: 81%; controls: 24%; P<0.0001), and more frequently experienced ensuing viral infections in the lower respiratory tract (subgroup 1: 74%; subgroup 2: 88%; controls: 25%; P<0.0001). Sixteen percent of these children had coinfections by 2 or more viruses and revealed more severe respiratory illness. CONCLUSIONS: The present epidemiologic study on viral upper RTI in immunocompromised children revealed a high virus-associated morbidity which was particularly prominent in HSCT recipients. In these children, detection of viral coinfections was identified as a risk factor for a severe course of lower RTI.

Molecular diagnosis and management of viral infections in hematopoietic stem cell transplant recipients.

Viral infections after allogeneic hematopoietic stem cell transplantation (HSCT) are important complications associated with high morbidity and mortality. In this setting, reactivations of persisting latent viral pathogens from donor and/or recipient cells play a central role whereas the sterile environment of transplant units renders new infections less likely. The viruses currently regarded as most relevant in the HSCT setting include particularly the herpes virus family--specifically cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV-6)--as well as human adenoviruses (AdVs) and the polyoma virus BK (BKV). Timely detection and monitoring of virus copy numbers are prerequisites for successful preemptive treatment approaches. Pre- and post-transplant surveillance by sensitive and quantitative molecular methods has therefore become an essential part of the diagnostic routine. In this review, we discuss diagnostic aspects and the clinical management of the most important viral infections in HSCT recipients, with a focus on pediatric patients.

Targeted expression of herpes simplex virus thymidine kinase in adenovirus-infected cells reduces virus titers upon treatment with ganciclovir in vitro.

BACKGROUND: Adenoviruses are a frequent cause of life-threatening infections in immunocompromised patients. Available therapeutics still cannot completely prevent fatal outcomes. By contrast, herpes viruses are well treatable with prodrugs such as ganciclovir (GCV), which are selectively activated in virus-infected cells by virus-encoded thymidine kinases. This effective group of prodrugs is not applicable to adenoviruses and other DNA viruses because they lack those kinases. METHODS: To render adenoviruses amenable to GCV treatment, we generated an adenoviral vector-based delivery system for targeted expression of herpes simplex virus thymidine kinase (HSV-TK) in wild-type adenovirus 5 (wt Ad5)-infected cells. HSV-TK expression was largely restricted to wt virus-infected cells by transcription of the gene from the Ad5 E4 promoter. Its activity is dependent on the adenoviral E1A gene product which is not produced by the vector but is only provided in cells infected with wt adenovirus. The anti-adenoviral effect of HSV-TK expression and concomitant treatment with GCV was assessed in vitro in four different cell lines or primary cells. RESULTS: E4 promoter-mediated HSV-TK background expression was sufficiently low to prevent cytotoxicity in the presence of low-levels GCV in cells not infected with wt Ad5. However, expression was several-fold increased in wt Ad5-infected cells and treatment with low levels of GCV efficiently inhibited wt Ad5 DNA replication. Genome copy numbers and output of infectious particles were reduced by up to > 99.99% and cell viability was greatly increased. CONCLUSIONS: We extended the concept of enzyme/prodrug therapy to adenovirus infections by selectively sensitizing adenovirus-infected cells to treatment with GCV.

Typing of human adenoviruses in specimens from immunosuppressed patients by PCR-fragment length analysis and real-time quantitative PCR.

Currently, 51 human adenovirus (AdV) serotypes, which are divided into six species (A to F), are known. AdV infections are a major cause of morbidity and mortality in immunosuppressed individuals, particularly in allogeneic stem cell transplant (SCT) recipients. Any AdV species may cause life-threatening disease, but little information is available on the clinical relevance of individual serotypes. The use of serological testing for serotype identification is limited due to the impaired immune response during the posttransplant period. A new molecular approach to serotype identification is presented here that exploits variable regions within the hexon gene. All serotypes belonging to the species A, B, C, E, and F can be determined by fragment length analysis of a single PCR product. For species C, which is the most prevalent in many geographic regions, an alternative technique based on serotype-specific real-time quantitative PCR was established. Of 135 consecutive pediatric patients screened for AdV infections after allogeneic SCT, 40 tested positive. Detailed analysis revealed the presence of 10 different serotypes; serotypes 1 and 2 from species C (C01 and C02) showed the highest prevalence, accounting for 77% of the AdV-positive cases. Representatives of other species were observed less commonly: serotype A12 in 6.5%; serotype A31 in 4.5%; and B03, B16, C05, C06, D19, and F41 in 2%. The approach to rapid molecular serotype analysis presented here provides a basis for detailed studies on adenovirus epidemiology and on the transmission of nosocomial infections. Moreover, in view of the increasing importance of tailored therapy approaches, serotype identification may in the future have implications for the selection of the most appropriate antiviral treatment.