NCT00264290.

Porcine circovirus 2 (PCV2) is a recently identified agent that has been associated with post-weaning multisystemic wasting syndrome (PMWS) in swine populations. In this report, the potential spectrum of disease associated with PCV2 is expanded by evidence of vertical transmission and associated reproductive failure. PCV2 was isolated from a litter of aborted piglets from a farm experiencing late-term abortions and stillbirths. Severe, diffuse myocarditis was present in 1 piglet associated with extensive immunohistochemical staining for PCV2 antigen. Variable amounts of PCV2 antigen were also present in liver, lung, and kidney of multiple fetuses. The presence of other agents that have been associated with fetal lesions and abortion in swine, including porcine parvovirus, porcine reproductive respiratory syndrome virus, encephalomyocarditis virus, and enterovirus, could not be established.

Recent studies of subjects infected with human immunodeficiency virus (HIV-1) have produced conflicting results about the extent of reconstitution possible in the CD4+ lymphocyte repertoire after highly active antiretroviral therapy (HAART). The effect of HAART on the incidence of opportunistic infections will probably depend on reconstitution of antigen-specific CD4+ lymphocyte responses to important pathogens, including cytomegalovirus (CMV), the leading cause of blindness in AIDS. Several studies have demonstrated an important role for CD4+ lymphocytes in controlling CMV replication in vitro and in clinical studies. It is now possible to quantitate antigen-specific CD4+ lymphocyte responses by flow cytometry. Using this method, we studied CMV-specific CD4+ lymphocyte responses in individuals infected with HIV-1 with and without a history of active CMV-associated end organ disease (EOD), and in those with quiescent CMV EOD after ganciclovir therapy and HAART. The presence of active CMV-associated EOD strongly correlated with loss of CMV-specific lymphocyte responses (P = 0.0004). In contrast, patients with no history of CMV-associated EOD and most patients with quiescent EOD after HAART demonstrated strong CMV-specific CD4+ lymphocyte responses. These data indicate that the loss of CMV-specific CD4+ lymphocyte responses in individuals infected with HIV-1 who have active CMV EOD may be restored after ganciclovir therapy and HAART, which provides evidence for functional immune reconstitution to an important pathogen.

Life-threatening opportunistic cytomegalovirus infection is a complication of the acquired immunodeficiency syndrome (AIDS) that occurs in 7.4% or more of patients with AIDS. Cytomegalovirus retinitis, colitis, esophagitis, and gastritis are the commonest manifestations of severe cytomegalovirus end-organ disease. Extensive trials with intravenous ganciclovir, a nucleoside analogue with myelosuppressive toxicity, have shown that ganciclovir halts the progression of cytomegalovirus retinitis and gastrointestinal disease. Since relapse is common when therapy is discontinued, most patients with AIDS need life-long maintenance therapy. The clinical response to ganciclovir therapy is usually accompanied by diminished shedding of the virus. Based on limited data, foscarnet, a pyrophosphate analogue, also appears to have some efficacy in treating cytomegalovirus infection. Unlike ganciclovir, foscarnet does not cause myelosuppression. An important direction for future clinical research is the development of more effective and less toxic therapy, as well as orally bioavailable drugs for maintenance therapy.