Ha, Suliman Tayseer
(2006)
Anti-nucleosome antibodies as a disease activity marker in patients with systematic lupus erythematosus.
Masters thesis, Universiti Sains Malaysia.
Abstract
The clinical aspect of measuring the level of anti-nucleosome antibodies in patients with
systemic lupus erythematosus (SLE) has been well established and it is claimed that their
presence is associated with the disease activity. The overall aim of this study was to
measure the level of anti-nucleosome· antibodies in the SLE patients, to determine the
sensitivity as well as the specificity of these antibodies in the diagnosis of the disease. The
evaluation of the relationship between the levels of anti-nucleosome antibodies, the disease
activity as well as and other markers (anti-dsDNA antibodies, C3, C4 and CRP) were also
compared and assessed.
In this cross sectional study, all patients were selected from Hospital Universiti Sains
Malaysia (HUSM), who were either attending the medical specialist's clinic or have been
admitted to the medical wards. Ninety SLE patients, forty-five other connective tissue
diseases (e.g., rheumatoid arthritis, mixed connective tissue disease, scleroderma,
Raynaud's syndrome and Sjogren's s~drome) and ninety normal controls were tested for
anti-nucleosome antibodies by enzyme linked immunosorbent assay (ELISA), anti-dsDNA
and ANA by Immunofluorescence (IF), C3, C4 and CRP by immunoturbidometry
techniques. SLE diseases activity was evaluated by using SLE-Disease Activity Index
(SLEDAI) score. A patient is defined as having active SLE when SLEDAI score is more
than 5.0
Out of 90 SLE patients, anti-nucleosome antibodies were positive in 52% of patients,
whereas these antibodies were positive in 7% of patients with other connective tissue
diseases. The median concentration of anti-nucleosome antibodies was significantly
different between SLE patients and other connective tissue diseases. None of the normal
controls was found to be positive for these antibodies. Anti-dsDNA antibodies were
positive in 3 7% SLE patients, whereas these antibodies were positive in 8% of patients with
other connective tissue diseases. None of the normal controls was found to be positive for
these antibodies. ANA was found to be positive in 81% SLE patients, in 61% of patients
with other connective tissue diseases and 7% in normal controls. Anti-nucleosome
antibodies had a sensitivity of 52%, whereas anti-dsDNA antibodies had a sensitivity of
37%. The specificity of anti-nucleosome and anti-dsDNA antibodies was 98% and 97%
respectively. ANA had sensitivity and specificity of 81% and 75% respectively. Antinucleosome
antibodies were positive in 98% of patients with active SLE, whereas these
antibodies were positive in 14% of patients with inactive SLE. The median concentration of
anti-nucleosome antibodies was significantly different between active and inactive SLE
patients. Anti-dsDNA antibodies were found to be positive in 61% of patients with active
SLE and in 16% of patients with inactive SLE. Anti-nucleosome antibodies had a stronger
correlation than anti-dsDNA antibodies with SLEDAI score. The median concentration of
C3 and C4 was significantly different between active and inactive SLE patients, and
showed an inverse and significant correlation with SLEDAI score, whereas the median
concentration of CRP was not significantly different between active and inactive SLE.
In conclusion, anti-nucleosome antibodies test is a recently developed test that may help in
diagnosis of SLE patients. Anti-nucleosome antibodies are highly sensitive and specific for
the diagnosis of SLE, especially when the anti-dsDNA antibodies are absent. Thus antinucleosome
antibodies test can be a better tool for the diagnosis of SLE. Anti-nucleosome
antibodies have a stronger and significant correlation with SLEDAI score than other
traditional disease activity markers. Therefore, it can be a useful and additional disease
activity marker to other laboratory tests that can help in the assessment SLE disease
activity.
Actions (login required)
 |
View Item |
