Human cytomegalovirus in patients with systemic lupus erythematosus

Abstract

The objective of this study was to determine the frequencies of human cytomegalovirus (HCMV) infection and HCMV genome copy number in blood of consecutive (treated from several months to several years) systemic lupus erythematosus (SLE) patients (22 women). The obtained results were compared to the healthy controls (15 women). All patients fulfilled at least four of the 1982 revised American rheumatism association (ARA) classification criteria for SLE. Our patients demonstrated three or four of the nine possible organ systems involved and most of them had mild SLE with SLE disease activity index (SLEDAI) score < 10 at time when blood samples were collected to detect HCMV. Quantitative analysis of HCMV genome was performed with aid of sequence analyzer ABI PRISM ^TM 7700 Perkin Elmer. Primers and probe were constructed on the basis of IE4 region of HCMV genome. The viral load was expressed as log₁₀ of calculated HCMV genome copy number. Qualitative analysis revealed that 100% of our SLE patients were infected with HCMV, whereas in the control group only 73% of persons were HCMV positive. Statistically significant difference was demonstrated when the strength of the association between SLE or controls and infection of HCMV was calculated (estimated by Fisher's exact test, P value = 0.02). Higher viral DNA copy number was observed in whole blood of SLE patients than in the control group (338.45 ± 221.76 and 229.00 ±405.61 copies/ml respectively) but did not reach statistical significance level (95% confidence interval from 170.41 to 249.32, P = 0.71). Furthermore percentage of patients with HCMV-DNA copy number >2.0 × 10² copies/ml was statistically significantly higher than this one in controls. The data show association between HCMV infection and SLE, which should be taken into account during the course of SLE.