CD27+IgD+B cells Demonstrate
Dampened IgM-Producing competency in SLE
To determine the functional changes of
CD27+IgD+B cells,we then examined
the production of IgM by CD27+IgD+B
cells in SLE patients. CD27+IgD+B
cells from active SLE patients
(SLEDAI>5) and healthy
individuals were isolated by flow cytometry sorting and subjected to
ELISPOT and QPCR analyses. ELISPOT analysis showed that under SLE
circumstance, the IgM-producing capacities of these cells were dampened
(Figure 3A). QPCR analyses further confirmed that the IgM transcripts of
these CD27+IgD+B cells were
significantly decreased in SLE (Figure 3B). Taken together, these
results indicated that CD27+IgD+B
cells were functionally impaired in producing IgM in SLE.
CD27+IgD+B cells are recovered in SLE patients with disease remission after
therapy
To ascertain the usefulness of
CD27+IgD+ B cells as a biomarker for
disease activity, we further evaluated whether these cells would be
recovered after effective therapy. 12 patients who were diagnosed as SLE
were studied when they were in relapse and 4 weeks after the initiation
of treatments. As shown in Table 2,
after treatments reduced significantly disease activity as measured by
SLEDAI. The anti-dsDNA and 24h urinary protein were decreased with the
serum C3 and C4 normalized to some extent. The total number of leukocyte
and platelet were increased after the treatments.
The frequency of
CD27+IgD+B cells were examined
before and after 4 weeks of initiation of treatments are shown in Figure
4A. As measured by SLEDAI, all patients showed a significant reduction
in disease activity after treatment (Figure 4B) and the frequency of
CD27+IgD+B cells was significantly
increased (Figure 4C). All these results suggested that the impaired
CD27+IgD+ B cells in SLE patients
could be recovered after effective therapy, indicating their deficiency
might be correlated with the development of SLE.