Evidence for the presence of androgen receptors in the synovial tissue of rheumatoid arthritis patients and healthy controls

OBJECTIVE

To study the presence of androgen receptors in the synovial tissue of male and female patients with rheumatoid arthritis (RA) and matched healthy controls.

METHODS

Both site I (high affinity, low binding capacity) and site II (reduced affinity, higher binding capacity) androgen receptors were investigated in soluble and nuclear fractions of homogenized synovial samples, using the dextran-coated charcoal method. The finding of pure, high-affinity site I receptors in both fractions was considered indicative of androgen receptor positivity. In order to determine what type of synovial cell was positive for androgen receptors, cryosections of synovial tissues were immunostained with a specific monoclonal anti-androgen receptor antibody (MAb), using both immunofluorescence and immunoperoxidase techniques. Double immunostaining with this MAb and specific MAb directed toward different macrophage/granulocyte antigens was also performed.

RESULTS

Remarkable differences were found between male and female controls: Most males were positive for androgen receptors, and most females were negative. The fetomolar content of androgen receptor in the nuclear fraction was fairly constant, but the soluble fraction showed a higher femtomolar concentration in female RA patients than in controls of either sex, as well as in male RA patients compared with female RA patients. The androgen receptor-positive cells in both RA and control synovial cryosections were found by immunostaining to be macrophage-like synoviocytes, and were also found to be HLA-DR positive.

CONCLUSIONS

The immunosuppressive action exerted by androgens might, at least in part, be mediated through their interaction with macrophage-like synoviocytes functioning as antigen-processing and antigen-presenting cells in rheumatoid synovia.

Tenascin and fibronectin distribution in human normal and pathological synovium

Tenascin is a glycoprotein found mainly in the extracellular matrix of developing and malignant tissues. The distribution of this molecule in normal and pathological synovia from patients with osteoarthritis (OA) and rheumatoid arthritis (RA) was investigated by indirect immunofluorescence utilizing specific monoclonal antibodies. The same technique was used to study total fibronectin (tFn) in synovial tissues as well as ED-A and ED-B containing fibronectin (Fn) isoforms (A-Fn, B-Fn), generated by alternative splicing of pre-mRNA. Tenascin was found in normal synovium just beneath the whole lining cell layer. However, a higher density and spreading pattern of distribution was observed in OA and RA sections. A-Fn and B-Fn isoforms were prominent and widespread throughout the normal synovial lining; in hypercellular synovial lining (in RA and OA samples), A-Fn and B-Fn were also observed spreading in the sublining, as well as tFn.

Changes in fibronectin production in rat liver during cirrhotic evolution due to treatment with CCl4 and steroid hormones: correlation with plasmatic fibronectin

Previous our studies showed that some steroid hormones, as pure crystalline Progesterone (pPc) and 17-alpha-hydroxyprogesterone capronate (17 alpha HPC) heightened the cirrhogenic action produced in rat liver by carbon tetrachloride. Medroxyprogesterone (MPA), however, did not appear to promote cirrhosis, but increased just steatosis. In the present paper, we have studied the above mentioned steroid hormones for their possible capability of inducing changes in plasma fibronectin concentration. For this purpose, the soluble plasma fibronectin level was measured in female rats 45 days after CCl4-induced cirrhosis, and it was compared with the insoluble fibronectin of liver (detected by immunostaining) and the collagen content in the organ. The results obtained show that, after treatment with CCl4 and MPA, both plasma and liver fibronectin content strongly increases, whereas liver collagen content lowers. However, after treatment with CCl4 alone or in association with the other two steroid hormones, any changes in fibronectin content is not observable, but, on the contrary, is evident a heightened collagen production associated with a cirrhotic change of liver.

Sex hormones, HLA and rheumatoid arthritis

Recent evidence indicates that the HLA system might, in some way, regulate androgen concentrations. Male patients affected by rheumatoid arthritis have been shown to possess low serum testosterone levels associated with a particular HLA haplotype. Furthermore, androgen receptors have been recently described in macrophage-like synoviocytes that are HLA-DR positive. Since androgens generally are immunosuppressive, the possible mechanisms of their action in rheumatoid arthritis are here reviewed and discussed. It has now become evident that the well known relationship between sex hormones and the immune system is more complex than was previously suspected.

Adult-onset Still's disease associated to toxoplasma gondii infection

Adult-onset Still's disease is characterized by high spiking fever, evanescent maculopapular rash and arthritis. Several recent reports have associated its development with a variety of infectious agents. We describe the case of a 25-year old woman presenting high fever, maculopapular rash and seronegative polyarthritis associated with lymphoadenopathy, splenomegaly and neutrophil leucocytosis together with acute acquired toxoplasmosis. Other causes of systemic illness were excluded by appropriate laboratory, radiological and histological investigations. Clinical, radiological and laboratory findings as well as possible etiopathogenetic correlations among both pathological conditions are discussed. Toxoplasma gondii should be considered as a further possible triggering agent associated with the development of adult-onset Still's disease.

[Morpho-functional characteristics of reflux gastritis in patients after cholecystectomy and without cholecystectomy]

The aim of this study was to evaluate some biochemical and histopathological aspects in a group of patients with a view to identifying any differences depending on whether the pathology was associated with previous cholecystectomy or idiopathic. The study involved 23 patients (8 post-cholecystectomy cases and 15 ulcer-free dyspeptic patients) with the diagnosis of duodenogastric reflux gastritis confirmed by endoscopic histopathological evaluation. The following parameters were considered: 1) pH and bile salt concentration in gastric juice; 2) histological classification of antral biopsies (Niemela's criteria); 3) dyspeptic symptoms (dyspepsia, pyrosis and epigastric pain, sense of repletion, foul-tasting mouth) graded on a scale from 0 to 4. All parameters were considered in relation to whether or not Helicobacter Pylori was found in the histological specimens. No significant differences were found between the two groups for pH and bile salt values or for Helicobacter Pylori positivity. No relationship was observed between the Helicobacter Pylori and either the severity of the histological picture, the features of the biochemical parameters or the severity of the clinical symptoms. Such findings confirm the common pathophysiological pattern of reflux gastritis regardless of any permanent biliary tract alterations and the low importance of Helicobacter Pylori infection in determining this syndrome.

Androgen replacement therapy in male patients with rheumatoid arthritis

A hypogonadic condition characterized by low serum testosterone levels has been identified in male patients with rheumatoid arthritis (RA). Seven men with active RA were treated daily for 6 months with oral testosterone undecanoate plus a nonsteroidal antiinflammatory drug in an attempt to evaluate the immunologic response, the overall clinical response, and the sex hormone response to such replacement therapy. At the end of the 6 months, there was a significant increase in serum testosterone levels (P less than 0.05), an increase in the number of CD8+ T cells, and a decrease in the CD4+:CD8+ T cell ratio. The IgM rheumatoid factor concentration decreased significantly (P less than 0.05). There was a concurrent significant reduction in the number of affected joints (P less than 0.05) and in the daily intake of nonsteroidal antiinflammatory drugs (P less than 0.01). The well-known immunosuppressive action of androgens probably contributed to our findings in these RA patients.

Monoreactive and polyreactive rheumatoid factors produced by in vitro Epstein-Barr virus-transformed peripheral blood and synovial B lymphocytes from rheumatoid arthritis patients

The CD5 membrane molecule, initially identified as an exclusive T-cell marker, also defines a phenotypically and functionally distinct B-lymphocyte population. In normal individuals, CD5+ B cells are committed to secrete 'natural' polyreactive (auto)antibodies, that is antibodies, mainly IgM, endowed with multiple antigen-binding capabilities, including rheumatoid factor (RF) activity. At variance with this, in rheumatoid arthritis (RA) as well as in other autoimmune conditions, monoreactive autoantibodies binding with high affinity and specificity to a given self antigen have been isolated and the cells from which they originate differently related to the CD5+ B-lymphocyte subset. Here, we studied the proportions of CD5+ B cells and the characteristics, in terms of polyreactivity and monoreactivity, of RF produced by B lymphocytes in RA patients with classified disease activity. Our results suggest that patients with a more severe disease activity have higher proportions of CD5+ B cells and higher frequencies of B lymphocytes committed to secrete RF, with the characteristics of polyreactive antibodies. On the other hand, we did not find a significant difference between the proportions of peripheral B cells producing monoreactive RF in patients with high- versus patients with low-activity RA. However, in two highly active RA patients, we found that synovial fluid, compared with peripheral blood, was significantly enriched for (IgG and IgA) monoreactive RF-producing B cells.

[Macroglobulin alpha-2 in synovial fluid: relationship with reactants of the acute phase of rheumatoid arthritis]

Metalloproteinases (e.g. collagenase, elastase, stromelysin) are present in large amount in synovial fluid (SF) during rheumatoid arthritis (RA) and are actively involved in articular tissue damage. alpha 2-Macroglobulin (alpha 2M) functions as a "molecular trap" for proteinases and is considered the major inhibitor of metalloproteinases. We found increased concentrations of alpha 2M in SF of RA patients, significantly related to acute phase reactants, local inflammatory parameters and joint damage. The alpha 2M ratio between, RA SF and control SF, was found higher than between RA serum and control serum, indicating a selective localization and activity of alpha 2M in inflamed joint. The relationship between alpha 2M and the inflammatory parameters, including IL-6, is discussed.

Nail involvement in osteoarthritis

Two cases of nail involvement associated with primary interphalangeal osteoarthritis of the hand, including leukonychia and longitudinal nail ridge, are reported. Osteoarthritic changes of the distal interphalangeal joints may cause nail lesions by exerting direct pressure on the nail matrix or by interfering with local blood flow. Moreover, inflammation of the Heberden's nodes is often present and seems to participate in the development of nail alteration. In our patients, leukonychia disappeared after local steroidal anti-inflammatory treatment of the osteoarthritic node and longitudinal nail ridge disappeared after treatment with nonsteroidal anti-inflammatory agents.

Plasma glucose concentration in symptomatic osteoarthritis: a clinical and epidemiological survey

The clinical, pathological, and epidemiological relationships between fasting plasma glucose (FPG) concentrations and the sites of lesion in osteoarthritis (OA) were evaluated in 1026 patients. The mean FPG (99 +/- 22.2 mg/dL) was significantly higher in OA (p less than 0.01) than in the normal controls (88 +/- 19.9 mg/dL). In addition, the mean FPG (97.9 +/- 23 mg/dL) was significantly higher in female patients with OA (p less than 0.01) than in an osteoporotic sex-matched control group (92.8 +/- 24.5). FPG concentrations did not vary significantly according to the sites of the OA lesions. Fifty-six (5.5%) OA patients had long-term diabetes mellitus (FPG greater than 140 mg/dl). Few significant differences in the pathological and clinical findings were seen between normoglycemic and hyperglycemic OA patients, only the ESR (p less than 0.01) and pain at rest (p less than 0.02) being higher in the second group. These epidemiological data support the observation that hyperglycemia, which acts on matrix macromolecules, may be related to the development of bone degenerative disease.

Plasma and synovial fluid lanthanides in rheumatoid arthritis: variations after intra-articular therapy

Lanthanides (Ln), or rare earth elements, are detectable in trace amounts in organisms. Increased concentrations of Ln have been observed in rheumatoid arthritis (RA) in plasma (pl) and synovial fluid (Sf). We have evaluated pl and Sf concentrations of Ln (in particular La, Nd, Ce, Yb, Lu, Eu), in rheumatoid arthritis patients, before and after intra-articular steroid injection. Increased pl and Sf concentrations of Ln were confirmed in RA. No detectable synovial fluid concentrations of Ln were observed in healthy controls. A statistically significant Ln reduction (p less than 0.001) was observed in Sf 3 and 6 days after local steroid injection and in pl after 6 days. The decrease in Ln concentrations in Sf and pl, after antiphlogistic therapy, reflects the reduction of the inflammatory condition.

Adhesion of human dermal reticular fibroblasts on complementary fragments of fibronectin: aging in vivo or in vitro

Attachment, spreading, and microfilament reorganization have been evaluated in human dermal reticular fibroblasts isolated from the inner, upper aspect of the arm of a newborn male (RET5 cells) and a 78-year-old male (RET8 cells). Substrata were tested using a set of complementary fragments from individual polypeptide chains of human plasma fibronectin (pFN) or cellular FNs (cFN). With both cell classes, fragments containing the C-terminal heparin-binding (HepII) domain only elicited linear bundles of microfilaments in spreading cells but no stress fibers; fragments containing the RGDS-dependent cell-binding (CellI) domain elicited only partial spreading with condensations of F-actin at ruffling membranes and at other regions along the plasma membrane. The minimum sequence required to obtain responses identical to those on intact pFN (broad spreading with extensive stress fiber formation) was found in fragment 155 (F155) from the beta chain of pFN; F155 contains both HepII and CellI domains. In contrast, the analogous fragment from the alpha chain of pFN (F145) was notably less effective for generating stress fibers. This evidence along with the better attachment, spreading, and microfilament bundle formation on the HepII fragment from the beta chain than the analogous fragment from the alpha chain indicates that the extra type III homology unit permits more effective interaction of beta chain fragments with cell-surface heparan sulfate proteoglycan and possibly integrin (binding efficiency to the substratum was similar for fragments from both chains). Therefore, alternatively spliced sequences that neighbor binding domains can play significant roles in the interaction of the domain with cell-surface receptors of dermal fibroblasts. Comparison of RET5 responses with those of RET8 cells has identified changes in adhesive mechanisms as cells undergo "aging" processes. Attachment and microfilament bundle formation were far more effective for RET5 cells than for RET8 cells on any of the HepII fragments. Conversely, RET8 cells were far more sensitive to an RGDS-containing peptide in their medium on CellI fragments than RET5 cells. These results together indicate that in vivo aging leads to greater dependence upon cell-surface integrin binding and less dependence upon heparan sulfate proteoglycan binding for responses on FN matrices. When RET5 cells entered senescence (in vitro aging), they also became much more sensitive to peptide A. On several fragments and on intact pFN, RET8 cells generated very thick stress fibers that were observed only on one fragment with RET5 cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Sex hormone status of male patients with rheumatoid arthritis: evidence of low serum concentrations of testosterone at baseline and after human chorionic gonadotropin stimulation

Serum concentrations of luteinizing hormone, follicle-stimulating hormone, prolactin, 17 beta-estradiol, testosterone, androstenedione, dehydrotestosterone, dehydroepiandrosterone sulfate, and cortisol were examined in 14 men with rheumatoid arthritis (RA) and in age-matched osteoarthritis controls. Hypophyseal, adrenal, and testicular responses to stimulation with luteinizing hormone-releasing hormone, adrenocorticotropin, and human chorionic gonadotropin, respectively, were evaluated in 8 RA patients and in 8 age-matched healthy volunteers. Basal serum testosterone concentrations were significantly lower in male RA patients than in the osteoarthritis control subjects (P less than 0.01). After human chorionic gonadotropin stimulation, serum concentrations of testosterone were also lower in the RA patients than in normal healthy controls (P less than 0.05). These findings suggest that diminished testicular steroid biosynthesis might contribute to the serum testosterone deficiency observed in male RA patients.

Differential expression of the ED sequence-containing form of cellular fibronectin in embryonic and adult human tissues

Monoclonal mouse hybridoma antibodies were obtained for secreted cellular fibronectin (cFn) from A8387 fibrosarcoma cells. One of them, 52-DH1 (DH), reacted exclusively with cFns but not with plasma Fns (pFns) in immunoblotting and solid-phase EIA. The DH antibody also recognized thermolysin cFn fragments and beta-galactosidase-Fn fusion protein which contained the ED sequence specific to at least some forms of cFns. On the other hand, the DH antibody failed to recognize a fusion protein that was otherwise identical but lacked the ED sequence. Thus, the antigenic determinant for the DH antibody was located to the ED sequence. The DH antibody was then used to study the expression of ED sequence containing cFn (EcFn). For comparisons, another monoclonal antibody, 52BF12 (BF), recognizing equally well both pFns and cFns, was used. Immunoblotting of pFn fragments indicated that this antibody had the antigenic determinant at or close to the cell-binding site of Fn. EcFn was revealed by the DH antibody in embryonic and adult fibroblasts and in a variety of other cultured normal and malignant human cells. In embryonic tissues EcFn was abundant in developing basement membranes, as shown in foetal kidney and muscle, while in adult tissues it was confined only to endothelia of larger blood vessels. Furthermore, in embryonic tissues the capillaries showed bright EcFn-positivity not found any more in adult tissues. Human plasma contained a small quantity of EcFn, which may hence have an endothelial origin. EcFn was also prominent in the stroma of malignant tumours as well as in reactive benign conditions, such as granulation tissue and decidual cells. The results suggest that EcFn is a form of the protein which may have a particular role in developing and reactive tissues in embryos and adults.

Sex hormone status in women suffering from rheumatoid arthritis

We studied the sex hormone status of 21 seropositive (IgM-RF) women with rheumatoid arthritis (RA), who were subdivided according to their premenopausal and postmenopausal status. Age matched women with secondary osteoarthritis were used as controls. The hormones evaluated were luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL), 17-beta-estradiol (E2), progesterone (Pg), testosterone (T), delta 4-androstenedione (A), dehydrotestosterone (DHT), dehydroepiandrosterone sulphate (DHEAS) and cortisol (C). Normal concentrations of all the hormones considered were found in premenopausal women with RA. Statistically higher concentrations of T (p less than 0.05), A (p less than 0.05) and DHEAS (p less than 0.01) were observed in postmenopausal women with RA when compared to controls, whereas no differences were found for all other hormones studied. Although the significance of observed relative hyperandrogenism in postmenopausal women with RA is not clear, our data seem to indicate that sex hormone levels are altered in patients with RA.

Altered fibronectin distribution in cultured fibroblasts from patients with Ehlers-Danlos syndrome

Using the immunofluorescence technique we have studied the distribution of fibronectin in cultured fibroblasts from patients affected by Ehlers-Danlos Syndrome (EDS) types I, II and VI. In these cells the amount of fibronectin production is reduced with respect to normal fibroblasts; moreover fibronectin fibers are shorter, thicker, mainly pericellular and show intracytoplasmic accumulation. The altered fibronectin distribution may be the result of altered interactions of fibronectin with extracellular matrix components, either due to abnormal fibronectin or to changes in other extracellular matrix molecules (e.g. collagens, hyaluronic acid).

Different fibronectin concentrations in plasma samples drawn from the affected and unaffected arms of a pagetic patient

Plasma fibronectin concentrations in blood drawn from both arms of a pagetic patient affected only at the humerus, ulna and radius of the right arm were studied. Significantly higher levels were observed in the affected arm compared to the nonpagetic arm. Results suggest that in vivo synthesis of soluble fibronectin is associated with increased bone turnover and demonstrate the value of bilateral blood sample collection when localized bone disease is present.