the purpose of this study is to evaluate the role of insulin-like growth
factor binding protein-3 (IGFB -3) in inflammatory and degenerative Joint
diseases by estimating its level in the serum and synovial fluid of patients with
Rheumatoid arthritis (RA) and Osteoarthritis (OA) and correlating these levels
to the clinical features of these disorders.
Twenty RA patients, twenty-eight OA patients and fourteen healthy
controls were included in this study. All patients and controls were subjected to
the following; full history, clinical examination, and laboratory investigation
including TM, E'SR, estimation of the level of IGFBP-3 in both serum and
novial lIzzid by radioimmunoassay procedure. Plain x-ray for both knees &
ands was also included Patients with RA were divided according to their
radiological findings into erosive and non erosive subgroups, and according to
the mean disease activity grades (MDAG) into two groups, one including
patients with MDAG1 & 2 and another including patients with MDAG3 & 4.
OA patients were divided according to radiological findings into two
subgroups, one including patients with grade 1 & II and another including
grade HI & IV patients. And according to score of functional severity, we
subgrouped OA patients into two subgroups; one including patients with score
S.• 7 and another including patients with score 8.
The present study showed no sig.ncant difference between the serum
level of the IGFBP-3 of both RA and OA patients when compared to the
controls. A significant increase (P < 0.05) was found in the synovial IGFBP-3
of RA patients when compared to the controls. No significant difference was
found between synovial IGFBP-3 of OA patients when compared to the
controls. No significant correlation was found between the serum and synovial
IGFBP-3 of the L4 patients or OA patients with age and disease duration.
Moreover, no significant difference was ,found between-IGFBP-3 level in serum
and synovial .fluid of seropositive RA patients when compared to seronegative
RA patients. A significant negative correlation (P < 0.01) was found between
serum IGFBP-3 of RA patients and the hemoglobin concentration, also
between serum and synoviar 1GFBP-3 in OA patients.
From this study, we concluded that in RA, there may be a role of
IGFBP-3 in impairing the cartilage repair by decreasing the bioavailability of
IGF-1. However it is not the only inducer of cartilage destruction. On the other
hand, IGFBP-3 is not the primejactor inhibiting cartilage repair in OA. The
physiological significance of IGFBP-3 and the proteolytic enzyme activity is
still unclear. The regulatory role of the IGF-1, its binding protein and the
protease system is yet to be characterized |
