Successes and limitations of antimicrobial interventions in the setting of organ transplantation

Pulmonary nocardiosis in a heart transplant patient: case report and review of the literature

Pulmonary infection with Nocardia is an uncommon but serious infection found in immunocompromised patients. We describe a rapidly progressive pulmonary nocardiosis in a heart transplant patient. We then review the common clinical features of Nocardia infection in transplant recipients, outlining the challenges in its diagnosis and management. We also review the differences between Pneumocystis jiroveci prophylaxis regimens with respect to concomitant prophylaxis of Nocardia and other opportunistic infections.

Use of valganciclovir in patients with elevated antibody titers against Human Herpesvirus-6 (HHV-6) and Epstein—Barr Virus (EBV) who were experiencing central nervous system dysfunction including long-standing fatigue

BACKGROUND

Twelve patients with long-standing symptoms of central nervous system (CNS) dysfunction were found to have elevated antibody titres to human herpesvirus-6 (HHV-6) and Epstein-Barr virus (EBV). All patients had four or more of the following neurocognitive symptoms: impaired cognitive functioning, slowed processing speed, sleep disturbance, short-term memory deficit, fatigue and symptoms consistent with depression.

OBJECTIVES

We sought to determine whether elevated antibodies to EBV and HHV-6 indicated chronic viral activation in patients with CNS dysfunction and if their symptoms could be improved by suppressing viral activity with oral valganciclovir.

STUDY DESIGN

Patients with high IgG antibody titers against HHV-6 and EBV who were suffering from central nervous system dysfunction and debilitating fatigue for more than one year (median 3 years, range 1-8 years) were treated with 6 months of valganciclovir in an open label study.

RESULTS

Nine out of 12 (75%) patients experienced near resolution of their symptoms, allowing them all to return to the workforce or full time activites. In the nine patients with a symptomatic response to treatment, EBV VCA IgG titers dropped from 1:2560 to 1:640 (p = 0.008) and HHV-6 IgG titers dropped from a median value of 1:1280 to 1:320 (p = 0.271). Clinically significant hematological toxicity or serious adverse events were not observed among the 12 patients.

CONCLUSION

These preliminary clinical and laboratory observations merit additional studies to establish whether this clinical response is mediated by an antiviral effect of the drug, indirectly via immunomodulation or by placebo effect.

Pulmonary infections in non-HIV-immunocompromised patients

PURPOSE OF REVIEW

Pulmonary infections are the most frequent complications in non-HIV-immunocompromised patients and portend a high mortality. This scenario represents a challenging task for clinicians and an important subject of clinical research from different perspectives. This review comments on the results of relevant original articles in this area published from 2003 to the present.

RECENT FINDINGS

The present review addresses the etiology of the pulmonary infiltrates in immunocompromised patients, the use of new emerging diagnostic tools and medical devices in the clinical management of these infiltrates, and the greater understanding of the inflammatory immune response associated with infection in this setting.

SUMMARY

Advances in diagnostic tests and therapeutic devices are facilitating the clinical management of pulmonary infections. New challenges are emerging, however, such as the growing evidence regarding the important role of respiratory viruses as a common cause of lower respiratory tract infections. Finally, new insights into the mechanisms of the inflammatory response associated with pulmonary complications can help understanding their pathogenesis, improve prevention and diagnosis, and anticipate future therapeutic modalities.