Analyses of CD27++ Plasma Cells in Peripheral Blood from Patients with Bacterial Infections and Patients with Serum Antinuclear Antibodies

Abstract

The number of CD27 ++ plasma cells (PCs) in peripheral blood may be a valuable biomarker for systemic lupus erythematosus (SLE) disease management. More insights into the behavior of the PC population are, however, required to validate CD27 as a reliable biomarker. In the current study, we have monitored the PC compartment of patients with acute bacterial infections and patients with SLE and, in addition, examined the relationship between the presence of serum antinuclear antibodies (ANAs) and the number of peripheral PCs. Kinetic analyses in patients with bacterial infection revealed a 10–60-fold expansion of the CD27 ++ PC compartment that peaked at day 2–5 and returned toward normal values at day 7–9 after hospital admission. The transient expansion of the PC population appeared to be a late phenomenon in the process of recovering from a bacterial infection. SLE subjects had significantly increased frequencies of PCs compared with patients suspected of a connective tissue disease and healthy controls. In patients suspected of a connective tissue disease, no relationship was found between the presence of serum ANAs and the number of CD27 ++ PCs. Additionally, the presence of serum ANAs was not associated with abnormalities in other peripheral B-cell subsets. It remains to be established at which stage of SLE development the expansion of the PC compartment is initiated.

Longitudinal studies of the association between peripheral CD27++ plasma cells and systemic lupus erythematosus disease activity: preliminary results

“…On the other hand, a rise in CD27++ CD20− PCs appears not to be consistently associated with increased SLEDAI. A possible explanation for PC peaks without SLEDAI increase may be the presence of polyclonal B-cell activation due to infection and inflammation 5–8. Although the patients in our study had no clinical symptoms, the presence of a subclinical infection or inflammation cannot be completely excluded.…”

Significantly Higher Percentage of Circulating CD27highPlasma Cells in Systemic Lupus Erythematosus Patients with Infection than with Disease Flare-Up

“…Previous studies show that the expansion of CD27 high plasma cells is associated with the serological presence of particular autoantibodies, including anti-dsDNA, anti-Ro, anti-La, anti-Sm, and anti-histone antibodies 10-12. In our data, circulating CD27 high plasma cells seem to be important for the survey of disease activity in SLE patients without infection, because there is a significant correlation between the frequency of CD27 high plasma cells in peripheral blood and disease activity (i.e., SLEDAI, anti-dsDNA, C3 and C4 level, Table 5).…”

“…However, the percentage of circulating CD27 high plasma cells is also increased in non-SLE patients with bacterial infection 12. Distinguishing active lupus from infection is traditionally difficult.…”

Systemic lupus erythematosus and infections: Clinical importance of conventional and upcoming biomarkers

“…It has been described that CD27 high plasma cell frequency is high in SLE patients and that it correlates with SLE disease activity index (SLEDAI) and some ENA antibodies [36,37]. However, the percentage of circulating CD27 high plasma cells is also increased in non-SLE patients with bacterial infection [44].…”