Is the cytomegalovirus serologic status always accurate? A comparative analysis of humoral and cellular immunity.

Background: The precise knowledge of cytomegalovirus (CMV) status is important in a variety of clinical settings such as transplantation or blood transfusion. There are, however, various situations where an immunoglobulin-based diagnostic approach has limitations.
Methods: The CMV status of 388 individuals was determined by the analysis of both CMV-specific immunoglobulins and cellular immunity using a standard enzyme-linked immunosorbent assay and a rapid-flow cytometric approach, respectively.
Results: In 386 of 388 individuals, both assays yielded concordant results in assigning the CMV status (294 positive and 92 negative). In 2 of 94 (2.1%) CMV immunoglobulin (Ig) G-negative individuals, CMV-specific CD4 T cells were detectable. Repeated testing of the index and follow-up samples yielded one positive and one marginally positive IgG titer.
Conclusions: Both assays yielded highly concordant results. Thus, the T-cell-based approach may represent a reliable alternative for defining CMV status in any clinical situation where serologic testing is limited by borderline titers or by the presence of passively administered antibodies.