PCR detection of viral DNA in serum as an ancillary analysis for the diagnosis of acute mononucleosis-like syndrome due to human cytomegalovirus (HCMV) in immunocompetent patients

Human Cytomegalovirus Infection in Nonimmunocompromised Patients: A Retrospective Analysis and Review of the Literature

In a retrospective analysis of patients visiting the Outpatient Department of the Division of Infectious Diseases and Tropical Medicine over a period of 3 years, we found a high incidence of symptomatic nonsevere human cytomegalovirus (HCMV) infection in nonimmunocompromised patients. We present 11 symptomatic cases of HCMV infection in nonimmunocompromised patients with non-life-threatening symptoms like long-lasting depletion, fatigue, and subfebrile fever with or without muscular pain and arthralgia. Although the symptoms were not life-threatening, all of the patients suffered a prolonged duration of the disease until improvement. These cases reinforce the important fact that HCMV infections in nonimmunocompromised patients are not always asymptomatic. Therefore, HCMV infection should always be included in the differential diagnosis of patients with unspecific signs of disease like depletion, subfebrile fever, and arthralgia.

Cytomegalovirus (CMV)-Specific Perforin and Granzyme B ELISPOT Assays Detect Reactivation of CMV Infection in Inflammatory Bowel Disease

The role of cytomegalovirus (CMV) infection in the pathogenesis and exacerbation of Inflammatory Bowel Disease (IBD) has been unresolved. Typically, the CMV genome remains dormant in infected cells, but a breakdown of immune surveillance can lead to re-activation of viral replication in the gut mucosa, which is not necessarily associated with viremia or changes in antibody titers. We hypothesized that the detection of CMV-specific CD8 effector T cells should permit the distinction between dormant and active CMV infection. As CD8 effector T cells, unlike memory CD8 T cells, have perforin (PFN) and granzyme B (GzB) preformed in their cytoplasmic granules, we employed single cell resolution ELISPOT assays to measure the CMV antigen-triggered release of these molecules by CD8 T cells isolated from subjects with IBD, and age-matched healthy controls. The frequencies of CMV-specific (GzB) and PFN-producing CD8 T cells were increased in IBD patients compared to healthy controls. Furthermore, the increased CMV reactivity was associated with active IBD disease and with longer disease duration. Notably, PCR on serum frequently failed to detect CMV DNA during flares. The data show that during active IBD there is a flare of CD8 T cell activity against CMV in a substantial proportion of IBD patients, suggesting CMV reactivation that serum PCR does not detect. While it remains open whether CMV reactivation is a cause or consequence of IBD, our data suggest that monitoring CMV antigen-specific effector CD8 T cells with GzB and PFN ELISPOT analysis can provide novel insights into the role of CMV infection in IBD. Additionally, our data have implications for the fields of transplantation, HIV, cancer, and autoimmune diseases, in all of which patient care critically depends on sensitive and reliable detection of a reactivation of CMV infection.

[Pulmonary involvement in the course of cytomegalovirus infection in an immunocompetent adult]

INTRODUCTION

Cytomegalovirus (CMV) infection in the immunocompetent is generally silent or it may present as a mononucleosis like syndrome but, rarely, it can lead to symptomatic manifestations.

CASE REPORT

An immunocompetent and previously healthy 43- year-old woman presented with fever, dyspnoea, liver cell necrosis and a mononucleosis syndrome. The CT scan showed diffuse ground-glass opacity. BAL and blood cultures were sterile. Urinary antigens (Legionella pneumophila, Streptococcus pneumoniae) and serology for atypical respiratory pathogens (Mycoplasma pneumoniae and Chlamydia sp.) were negative. A diagnosis of CMV pneumonia was established on serology (presence of anti-CMV IgM) and PCR detection of viral DNA in the serum. Without antiviral therapy, there was a favourable clinical outcome 1 week later and 1 month later the CT scan was normal.

CONCLUSION

CMV infection can lead, exceptionally. to a hypoxic pneumonia in the immunocompetent host. Antiviral therapy should not be prescribed systematically.

Limitations of polymerase chain reaction testing for diagnosing acute Epstein-Barr virus infections

Clinicians use molecular tests to detect Herpesviridae from blood without fully appreciating limitations of testing. Studies are needed to enhance our understanding of the impact of Herpesviridae latency on molecular testing. We retrospectively performed quantitative Epstein-Barr virus (EBV) on sera from patients between the ages of 1 and 30 who demonstrated serologic evidence of acute EBV (n = 50) or remote EBV (n = 50) infection. Epstein-Barr virus DNA was detected in 70% of acutely infected and 4% of remotely infected patients. Sera from acutely infected patients had higher EBV copy number than convalescent sera. Our results suggest that serology should be performed as the initial diagnostic test for acute EBV. The role for polymerase chain reaction in immunocompromised patients with impaired antibody responses or as a 2nd-line diagnostic test when serologic results are equivocal deserves further study.

Concurrent detection of human herpesvirus type 6 and measles-specific IgMs during acute exanthematic human parvovirus B19 infection

A familial outbreak of human parvovirus B19 infection is described in which serological tests carried out routinely for determining the causal agent of febrile rashes of viral etiology failed to yield a definitive diagnosis. Concurrent detection of serum IgMs to parvovirus B19 and to heterologous viruses such as human herpesvirus type 6 (HHV-6) and measles virus complicated interpretation of the data. IgG avidity tests and investigation and testing for the presence of viral DNA in sera by PCR were required to confirm parvovirus B19. The study stresses the importance of avidity and PCR tests to obtain a firm diagnosis of febrile exanthematic viral diseases.