Early diagnosis and successful treatment of acute cytomegalovirus encephalitis in a renal transplant recipient.

We report the case of a 40-year-old male HIV-negative renal transplant patient with allograft rejection and immunosuppressive therapy who presented with acute cytomegalovirus (CMV) encephalitis. CT and MRI of the brain were normal but EEG showed diffuse slowing and dysrhythmia. In cerebrospinal fluid (CSF) initially 81 cells/microliters were found and immunocytochemistry showed a decreased CD4/CD8 ratio and increased values of activated lymphocytes, natural killer cells and immunoglobulin-containing cells. CMV-specific IgM antibodies in CSF and serum, immunostaining of CMV antigen in CSF cells and virus culture from CSF and urine were negative. During the first 3 weeks of illness no intrathecal production of immunoglobulins could be detected. Early diagnosis of CMV encephalitis was made by in situ hybridization (ISH) on CSF cell preparations and the polymerase chain reaction (PCR) which was positive in CSF and blood. On day 26 diagnosis was confirmed by detection of CMV-specific intrathecal IgG production. The patient was treated with ganciclovir, anti-CMV immunoglobulins and intrathecal beta interferon. He recovered completely after 2 months. Our data demonstrate the usefulness of ISH and PCR in the early diagnosis of CMV encephalitis and perhaps may encourage the use of intrathecal beta interferon in other patients with this disease.