Viral infections in severely immunocompromised cancer patients

Advances in the management of viral infections

Viral infections are common in cancer patients. The risk and severity of infection are influenced by patient, disease, treatment, and viral factors. Severe viral infections are more likely to occur in treatment regimens that are more immunosuppressive. Historically, the most frequent severe infections have been due to herpesviruses, but more recently, other pathogens, especially community respiratory and hepatitis viruses, have received increasing attention as major viral pathogens in cancer patients. Because of the new diagnostic assays and the introduction of better therapeutic options, knowledge of viral infections is important in optimizing antineoplastic therapies.

Assessment of oral cytological changes associated with exposure to chemotherapy and/or radiotherapy

BACKGROUND

Death from cancer is high in Sudan, with low survival rates, as most of the patients present with advanced disease. Most patients receive high and repeated doses of radiotherapy or chemotherapy. The aim of this study was to investigate the feasibility of using cytological evaluation to detect oral epithelial atypia amongst these patients. As a part of the continuous development in cancer therapy, this case control study was conducted in Khartoum, Sudan.

METHODS

Papanicolaou stained oral mucosal cells were obtained from 100 cancer patients receiving radiotherapy and/or chemotherapy (ascertained as cases), 50 cancer patients not exposed to either therapy (control 1), and 50 apparently healthy individuals (control 2).

STATISTICAL ANALYSIS

The data was analyzed by using a computer SPSS program, to obtain the Chi-square test.

RESULTS

Without prior knowledge of the subjects' group, oral epithelial atypia was detected in 7% of the cases. Inconclusive features of cytological atypia were observed in 13% of the cases. Atypia was not observed in both the control groups. Inflammatory infiltrate and viral cytopathic effects were identified in 32% and 8% of the cases respectively.

CONCLUSION

Cytological atypia, viral infections, and inflammatory infiltrates were detected after exposure to radiotherapy and/or chemotherapy.

Nonimmunosuppressive chemotherapy: EM011-treated mice mount normal T-cell responses to an acute lymphocytic choriomeningitis virus infection

Myelosuppression and associated immunosuppression are major problems in cancer chemotherapy. Thus, infection remains a significant source of morbidity and mortality during chemotherapy of cancer patients. Viral infections, particularly herpes simplex virus, varicella zoster virus, and cytomegalovirus, result either due to reactivation of latent viruses or new infections as sequelae of chemotherapy and debilitated cell-mediated immunity. Ultimately, the resolution of these infections can only be achieved after the control of malignancy and regaining the patient's ability to mount adequate immune responses. We show here that EM011, a tubulin-binding, nontoxic, orally available anticancer agent, does not alter absolute CD4(+), CD8(+), B220(+), and NK1.1(+) cell counts in immunocompetent mice. More importantly, EM011 treatment at tumor-suppressive dosages (300 mg/kg) does not suppress cell-mediated immune responses in mice experimentally challenged with acute lymphocytic choriomeningitis virus infection, in that mice mount robust virus-specific CD8(+) and CD4(+) T-cell immune responses while maintained on daily drug treatment. Thus, CD8(+) and CD4(+) T-cell expansion and acquisition of effector functions is not perturbed by EM011 treatment. These data provide compelling evidence to support the nonimmunosuppressive nature of EM011 therapy and provide strong impetus for combining chemotherapy with immunotherapy as a novel anticancer strategy.

Stress-associated immunomodulation and its implications for responses to vaccination

The rapidly growing field of psychoneuroimmunology involves the elucidation of the complex interactions between the CNS, the endocrine system and the immune system and its effects on health. Although the mechanisms involved in this bidirectional communication is not yet fully understood, studies in psychoneuroimmunology have shown that stress, through the hypothalamic-pituitary-adrenal and the sympathetic-adrenal-medullary axes, can induce modulation of the immune system. In this review, we discuss human studies and animal models, which focus on psychological stress and its effects on the immune response to vaccination, emphasizing the implications of these effects on health.

Stress-induced immunomodulation and the implications for health

There are complex bi-directional interactions among the central nervous system (CNS), the endocrine system, and the immune system. Although the mechanisms of this bi-directional communication is not yet fully understood, studies in the field of psychoneuroimmunology (PNI) have shown that stress, through the hypothalamic-pituitary-adrenal (HPA) and the sympathetic-adrenal medullary (SAM) axes, can result in the dysregulation of the immune system. In this review, we discuss human studies and animal models, which focuses on psychological stress emphasizing the implications of these effects on wound healing and infectious diseases.

Improved identification and differentiation of varicella-zoster virus (VZV) wild-type strains and an attenuated varicella vaccine strain using a VZV open reading frame 62-based PCR

A new method was developed to identify and differentiate varicella-zoster virus (VZV) wild-type strains from the attenuated varicella Oka vaccine strain. The PCR technique was used to amplify a VZV open reading frame (ORF) 62 region. A single specific amplicon of 268 bp was obtained from 71 VZV clinical isolates and several laboratory strains. Subsequent digestion of the VZV ORF 62 amplicons with SmaI enabled accurate strain differentiation (three SmaI sites were present in amplicons of vaccine strain VZV, compared with two enzyme cleavage sites for all other VZV strains tested). This method accurately differentiated the Oka vaccine strain from wild-type VZV strains circulating in countries representing all six populated continents. Moreover, the assay more reliably distinguished wild-type Japanese strains from the vaccine strain than did previously described methods.

Stress-induced immunomodulation: impact on immune defenses against infectious disease

It is now accepted that there are complex interactions among the central nervous system, the endocrine system, and the immune system. Although the mechanisms of this bi-directional communication is not yet fully understood, studies in the field of psychoneuroimmunology (PNI) have shown that stress, through the hypothalamic-pituitary-adrenal (HPA) and the sympathetic-adrenal medullary (SAM) axes, can induce modulation of the immune system. In this review, we discuss human studies and animal models, which focus on psychological stress and its effects on the immune defense against infectious agents, emphasizing the implications of these effects on health.

Stress and immunity: implications for viral disease and wound healing

It is now well established that psychological stress can downregulate the cellular immune response. Communication between the central nervous system and the immune system occurs via a complex network of bidirectional signals linking the nervous, endocrine, and immune systems. Stress disrupts the homeostasis of this network, which in turn, alters immune function. In this review, we discuss the role of stress in modulating cellular immune function and the potential health implications of this downregulation.

The clinical utility of viral quantitation using molecular methods

BACKGROUND

The quantitation of viral nucleic acids in biological fluids has become increasingly desirable over the past several years. To this end, a number of quantitative molecular procedures have been developed.

OBJECTIVES

The objective was to review the current literature on the molecular techniques used in the quantitation of viral nucleic acids and to assess the appropriateness of these methods for clinical use.

RESULTS

Assays involving both target and signal amplification are now available for the accurate and precise quantitation of viral burden in infected patients. These methods include quantitative polymerase chain reaction (PCR), branched chain signal amplification (bDNA), nucleic acid sequence-based amplification (NASBA) and the SHARP signal and hybrid capture systems. Our understanding of the natural history and pathogenesis of viruses such as the human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV) and Epstein-Barr virus (EBV) may be greatly facilitated by accurate determinations of viral and infected cell burden. Quantitation of viral load in infected individuals may also be useful to assess disease progression, monitor the efficacy of therapy and to predict treatment failure and the emergence of drug-resistant viruses.

CONCLUSION

Precise, accurate and reproducible quantitation of viral load is now feasible. Molecular assays for viral quantitation should have a considerable impact on medical research and clinical care.