[Expression of urokinase-type plasminogen activator (uPA) and uPA receptor (uPAR) plays a role in destruction of joint tissue in rapidly destructive coxarthropathy (RDC)]

OBJECTIVE

Proliferation of small vessels including capillaries in joint tissues is one of the significant histopathological features of rapidly destructive coxarthropathy (RDC). To examine the relationship between the angiogenesis and bone destruction, expression of urokinase-type plasminogen activator (uPA) and uPA receptor (uPAR), which are necessary for angiogenesis was histochemically investigated.

MATERIALS AND METHODS

Synovia and cartilage-bone tissues of femoral head were obtained from RDC patients at total hip replacement (THR). These joint tissues were fixed with 4% paraformaldehyde, and cartilage-bone tissues were decalcified, additionally. Immunohistochemical staining was performed on paraffin sections, using monoclonal antibodies against human uPA and uPAR.

RESULT

There was a difference between expression of uPA and that of uPAR. Expression of uPA was observed in many types of cells such as osteoclasts, giant cells, fibroblast-like cells and macrophages, of which osteoclasts and giant cells were most prominent. On the other hand, expression of uPAR was detected mainly in fibroblast-like cells and macrophages and rarely seen in osteoclasts and giant cells.

CONCLUSION

These results indicate that uPA-plasmin system contributes to bone destruction in RDC, and furthermore, that fibroblast-like cells and macrophages play an important role in activation of uPA-plasmin system.

Enhanced neutrophilic granulopoiesis in rheumatoid arthritis. Involvement of neutrophils in disease progression

OBJECTIVE

To investigate enhanced granulopoiesis in bone marrow of patients with rheumatoid arthritis (RA), and the role of neutrophils in RA pathogenesis.

METHODS

Aspirated bone marrow cells and peripheral blood leukocytes from patients with RA and non-RA patient controls were analyzed morphologically and by 2 color flow cytometry. Thirteen iliac bones (8 RA, 5 non-RA) were examined by light and transmission electron microscope (TEM).

RESULTS

The percentage of CD15+CD16- cells (immature neutrophils) in RA bone marrow (64.3+/-13.4%, mean +/- SD) increased significantly compared to that of non-RA controls (43.2+/-14.3%), whereas the fraction of CD15+CD]6+ cells (mature neutrophils)was greatly decreased (RA 21.8+/-10.1%; non-RA 38.1+/-8.9%). The absolute number of CD15+CD16- cells also increased markedly in RA bone marrow. The ratio of immature cells to the total granulocytes (% CD15+CD16- to % CD15+) correlated with the Lansbury Index score (R = 0.76, p<0.0001). TEM observations revealed that abundant immature neutrophils adhered closely to the trabeculae of the iliac bone. Margins of trabeculae were mostly irregular, especially in severe RA, and collagenous fibers frequently disappeared in those trabeculae with ragged margins.

CONCLUSION

In RA bone marrow, immature neutrophils (CD15+CD16-) were markedly increased in number; by contrast, no changes were found for mature cells. Augmented production of immature neutrophils (at the promyelocyte-to-myelocyte stage) might lead to the destruction of collagenous fibers in RA bone trabeculae, as revealed by TEM. Generalized bone destruction in RA might, at least in part, be caused by enhanced production of immature neutrophils.

The participation of IL-8 in the synovial lesions at an early stage of rheumatoid arthritis

Synovial tissues from Rheumatoid Arthritis (RA) were divided into three groups based on their histopathological findings and compared for their expression of IL-8 and monocyte chemotactic and activating factor (MCAF) by using immunohistochemistry and in situ hybridization. The levels of IL-8 as well as those of MCAF were markedly higher in the synovial fluid from RA joints. Synovial lining cells (SLC) and macrophages had an ability to produce IL-8 at an early phase of the disease. The presence of MCAF was restricted in macrophages at this stage. On the other hand, the production of IL-8 as well as MCAF were prominent in most components of the joints such as SLC, migrated monocytes, sublining fibroblastoid cells, endothelial cells or migrated neutrophils at an active phase. The expression of IL-8 or MCAF was low in fibrotic synovitis of RA. These data indicate that IL-8 generated from SLC and macrophages may participate to the inflammatory process in the early synovitis of RA.

[Expression of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in joint tissues of rapidly destructive coxarthropathy (RDC), analyzed by immunohistochemical study]

OBJECTIVE

Rapidly destructive coxarthropathy (RDC) is characterized by rapid destruction of hip joints, but its pathogenetic mechanism is still obscure. Matrix metalloproteinases (MMPs) are possibly one of the candidates concerning with this mechanism. We attempted histochemical investigation to demonstrate MMPs and tissue inhibitor of metalloproteinases (TIMPs) in joint tissues obtained from RDC patients to clarify their roles in the destruction mechanism.

MATERIALS AND METHODS

Joint tissues including synovia and cartilage-bone tissues were obtained from RDC patients at total hip replacement (THR). After fixation with 4% paraformaldehyde, cartilage-bone tissues were partly decalcified. We performed histochemical study for paraffin sections of these tissues by using avidin-biotin method. Antibodies used in this study were monoclonal antibodies to MMP-1, MMP-2, MMP-7, MMP-8, MMP-9, TIMP-1, TIMP-2 and polyclonal antibody to MMP-3.

RESULTS

Histological feature of RDC was severe destruction of cartilage and bone by invasion of non-specific granulation tissues composed of many small vessels, macrophages and fibroblastic cells. At the same time, RDC showed apparently fewer lymphocytic cells in these granulation tissues compare with rheumatoid arthritis. MMP-2 and MMP-9 were expressed most demonstrably in synovia and destructive regions of femoral heads, especially in osteoclasts, macrophages, and fibroblastic cells, while MMP-1, MMP-3, were slightly expressed only in the superficial layer of synovia in limited cases. MMP-8, usually contained in neutrophils, was not present in RDC. On the other hand TIMP-1 and TIMP-2 were presented throughout the synovia and destructive regions of femoral heads including fibroblastic cells, macrophages, osteoblasts and osteocytes.

CONCLUSION

Immunohistochemical study revealed obvious presence of MMP-2 and MMP-9 in synovia and destructive regions of femoral heads in RDC. Those evidence suggest that MMP-2 and MMP-9 share very important role in the destructive mechanism of RDC, possibly under imbalance between TIMPs.

Intercellular adhesion molecule-1 (ICAM-1) in the sera of patients with Graves' disease: correlation with disease activity and treatment status

Intercellular adhesion molecule (ICAM-1), a ligand for lymphocyte function-associated antigen-1 (LFA-1), plays an important role in a variety of immune-mediated mechanisms such as lymphocyte attachment to cultured Graves' thyroid cells. We report the detection of a soluble form of the ICAM-1 molecule (sICAM-1) in sera from patients with Graves' disease (GD) and other thyroid disorders. The mean (+/- SD) sICAM-1 concentration in 28 euthyroid control subjects was 1931 +/- 681 pmol/L. The mean sICAM-1 concentration in 25 untreated hyperthyroid patients with GD was significantly elevated (3065 +/- 890 pmol/L), and decreased significantly (2489 +/- 845 pmol/L) after treatment with antithyroid drugs and/or 131I. Of 14 GD patients who had been in remission following administration of antithyroid drugs, 12 had recurrent disease. In 10 of the 12 patients in whom GD recurred, the sICAM-1 concentration (3807 +/- 796 pmol/L) increased significantly. The mean sICAM-1 concentration in patients with hypothyroidism due to chronic thyroiditis (n = 15:2895 +/- 569 pmol/L) was significantly elevated over that of control subjects, and not different from untreated hyperthyroid patients. The mean sICAM-1 concentration in patients with subacute thyroiditis (n = 13: 3036 +/- 441 pmol/L) was significantly elevated, while the mean sICAM-1 concentration in patients with nodular goiter (n = 10: 2318 +/- 490 pmol/L) was within the normal range. These results indicate that mean serum sICAM-1 concentration was significantly elevated in patients with untreated GD, and it decreased after treatment and increased at the time of recurrence. Therefore, the elevated serum concentration of sICAM-1 in patient with GD probably reflects ongoing immune processes.

[Bone mineral density of the radius in patients with rheumatoid arthritis measured by dual energy X-ray absorptiometry]

Bone mineral density (BMD) of the radius was measured in 181 female patients with rheumatoid arthritis (RA) and 255 control subjects using dual energy X-ray absorptiometry (DXA). The BMD of RA patients was assessed according to patients' age and menopause and was compared with age-matched controls for various activity factors of RA and duration of the disease that might correlate with BMD. At stages I and II of premenopausal RA, generalised osteoporosis was not observed. At stages III and IV, the BMD decreased considerably in premenopausal RA patients at age of 45 years or older. There were significant correlations between the BMD of postmenopausal RA and all factors examined, many of which did not affect premenopausal RA. These results suggest that osteoporosis of female patients with RA is influenced only slightly by the disease itself, but it is secondary osteoporosis induced by decreased activities of daily living due to RA.

[Increased levels of circulating hyaluronate in the sera of patients with rheumatoid arthritis with special reference to joint destruction]

We sought to assess whether serum levels of hyaluronate (HA) in patients with rheumatoid arthritis (RA) are elevated and correlated with grade of joint destruction and with laboratory data. Circulating HA levels were determined by protein binding assay of serum from 236 patients and 19 healthy controls. The greatest elevations of HA were seen in RA patients (350.7 +/- 689.5 ng/ml) than controls (33.7 +/- 24.2 ng/ml). Their levels showed only weak correlation values of CRP in laboratory data. Although HA levels of sera in stage III and IV in Steinbrocker's classification revealed significantly higher on average than ones in stage I and II (p < 0.01), there were many cases with low HA levels even in stage III and IV. Comparing HA levels between the cases with progressive and non-progressive type of hip or knee joint destruction within a year, the former (1143.6 +/- 1746.0 ng/ml median 480.1 ng/ml) presented significantly higher HA levels than the latter (245.3 +/- 255.8 ng/ml median 140.0 ng/ml) (p < 0.01). Further, one of 7 cases followed by 4 years with extremely high levels of HA showed progression of joint destruction from grade III to IV in Larsen Grade in bilateral knee joints during these times, though there were no significant correlations between HA levels and laboratory data. From above results, levels of circulating HA in the sera of patients with RA correspond to the joint destruction, not to a result of one.

Change of prostaglandin E level in joint fluids after treatment with flurbiprofen in patients with rheumatoid arthritis and osteoarthritis

The prostaglandin E (PGE) level in the knee joint fluid was determined by radioimmunoassay before and after anti-inflammatory therapy with flurbiprofen in 8 patients with rheumatoid arthritis (RA) and 4 patients with osteoarthritis (OA). The level of PGE in RA joint fluids before the anti-inflammatory treatment was 9.5-1.2 ng/ml and in proportion with the leucocyte count in the joint fluid. A marked decrease of the PGE level was attained with flurbiprofen treatment in 4 patients whose initial PGE levels had been higher than 3.2 ng/ml, while 4 patients with lower PGE levels, namely, 1.4-1.2 ng/ml, did not respond to the drug treatment. In all the OA patients the PGE levels was no higher than 1.5 ng/ml and refractory to the anti-inflammatory therapy.