Soluble CD30: a serum marker for Epstein-Barr virus-associated lymphoproliferative diseases.

The soluble form of CD30 (sCD30), a member of tumor necrosis factor receptor superfamily, has been used as a marker of disease activity in various lymphomas. Epstein-Barr virus (EBV) is a potent stimulator of CD30 expression. The study aims to evaluate whether sCD30 can be used as a diagnostic marker for EBV-associated infectious mononucleosis (IM) and post-transplant lymphoproliferative disease (PTLD). Plasma from EBV seropositive healthy controls (N = 90), acute IM patients (n = 90), non-PTLD heart/lung transplant recipients (N = 30) and EBV-positive PTLD patients (N = 23) was tested for sCD30 using a commercially available ELISA kit. EBV DNA was tested by real time quantitative polymerase chain reaction assay. Significantly higher sCD30 levels were observed in acute IM patients (median 242.9 ng/ml) compared to EBV seropositive controls (median 15.7 ng/ml; P < 0.0001). These levels were highest in IM patients within 14 days of onset of illness. PTLD patients had significantly higher sCD30 levels (median 94 ng/ml) than healthy controls (P < 0.0001) and transplant patients (median 27 ng/ml; P = 0.0007). EBV DNA was detected mostly in acute IM and PTLD patients. In both cases there was a significant correlation between sCD30 and EBV DNA levels in plasma (P < 0.0001). This study demonstrates that sCD30 and EBV DNA levels can be used as potential markers for diagnosis of IM and PTLD.