Electron microscopic analysis of sequential liver biopsy samples from patients with rheumatoid arthritis. Correlation with light microscopic findings

We used electron microscopy (EM) to analyze 52 biopsy samples from 22 patients who were receiving long-term weekly oral doses of methotrexate (MTX) for the treatment of rheumatoid arthritis. Forty-eight biopsy samples were obtained after 2–6 years of continuous treatment, and 4 samples were obtained before treatment was begun. Specimens were graded for neutral fat, secondary and tertiary lysosomes, and smooth endoplasmic reticulum (SER) in hepatocytes, and for collagen in the perisinusoidal space (Disse's space). We examined the correlations between the EM findings and the light microscopic (LM) findings in the same biopsy specimens, and between the EM findings and the results of simultaneous monthly measures of aspartate transaminase, alkaline phosphatase, bilirubin, and albumin levels, as well as history of alcohol consumption before MTX treatment and monthly assessments of clinical status during the course of treatment. The presence of collagen was minimally increased in these sequential biopsy samples, whereas fat, lysosomes, and SER were decreased. The SER decrease was statistically significant. EM findings of collagen in the space of Disse did not correlate with early fibrotic changes observed with LM. Thus, after as long as 6 years of weekly oral treatment with MTX, hepatic ultrastructural changes are minimal and are not clinically significant. The use of EM for sequential biopsy studies allows the quantitation of long-term hepatic changes that may be more limited than the impression gained after LM analysis.     

Light and electron microscopic analysis of liver biopsy samples from rheumatoid arthritis patients receiving long-term methotrexate therapy

OBJECTIVE: We study liver damage in forty-two patients with rheumatoid arthritis (RA) using light (LM) and electron microscopy (EM) and assess histological changes after four years of treatment with methotrexate (MTX). PATIENTS AND METHODS: liver biopsies (LB) were taken before and after four years of treatment. Patients received weekly doses of between 7.5-15 mg of MTX. RESULTS: Fourteen per cent of the baseline LB presented mild perisinusoidal fibrosis (Roenigk IIIA) and the rest a lower Roenigk grade; EM identified an increase in collagen fibers in the Disse spaces in 50% of baseline LB. Neither microscopy technique revealed histological progression in any of the sequential LB. Variables that correlated with histological abnormalities were patient's age, length of evolution of the disease, alcohol consumption and biochemical data (gammaglutamate transferase and albumin); the cumulative dose of MTX was not correlated with worse histological findings. Correlation between the two microscopy techniques was good, though EM was more sensitive than LM for the detection of fibrosis. CONCLUSIONS: RA patients present with liver damage before treatment with MTX. The alterations are mild. At low doses MTX treatment is safe. In addition to the recommendations of the American College of Rheumatology, other factors associated with liver impairment are patient's age and length of evolution of the RA.     

Folate status of rheumatoid arthritis patients receiving long-term, low-dose methotrexate therapy

The folate status of 29 healthy control subjects, 16 rheumatoid arthritis (RA) patients taking methotrexate (MTX), and 20 RA patients who were not being treated with MTX was estimated by an assay of the folate-dependent enzymatic synthesis of serine from formate and glycine, which is termed the C1 index. Analysis of variance demonstrated that the specific activity of the enzyme system in lymphocytes was significantly lower in the MTX-treated group, with an activity approximately one-half that of the control and the non-MTX-treated groups. Since the C1 index is one of the first biochemical parameters found to be different between MTX-treated and non-MTX-treated groups, alterations in folate-mediated amino acid metabolism may be involved in the mechanism of response to MTX therapy. Use of the C1 index may assist in the development of protocols which preserve the efficacy of MTX therapy while minimizing toxicity.     

Efficacy and safety of 10-deazaaminopterin in the treatment of rheumatoid arthritis. A one-year continuation, double-blind study.

OBJECTIVE. To determine the long-term safety and efficacy of 10-deazaaminopterin (10-DAM) in the treatment of rheumatoid arthritis (RA). METHODS. A 1-year continuation of an initial 15-week randomized, double-blind clinical trial of 10-DAM and methotrexate (MTX). RESULTS. 10-DAM (n = 10) and MTX (n = 8) had comparable safety and efficacy profiles. One 10-DAM-treated and 2 MTX-treated patients experienced transient side effects; 1 MTX-treated patient experienced recurrent nausea and discontinued MTX. CONCLUSION. 10-DAM appears to be as beneficial and as safe as MTX for the treatment of RA.     

Immunologic studies of rheumatoid arthritis patients treated with methotrexate

Immunologic functions of peripheral blood mononuclear cells were studied in rheumatoid arthritis (RA) patients treated with methotrexate (MTX). Spontaneous IgM rheumatoid factor (IgM-RF) synthesis by unstimulated cultured blood mononuclear cells was seen in only 3 of 18 MTX-treated patients, compared with 31 of 54 RA patients who were not receiving long-acting drugs. Total IgM production by unstimulated cultured mononuclear cells, pokeweed mitogen-induced antibody synthesis, and plasma levels of IgM-RF were also lower in MTX-treated patients than in other RA patients. The numbers of circulating B cells, T4 and T8 cells, the T4:T8 cell ratio, and mitogen-induced proliferation indices were similar in MTX-treated and non-MTX-treated patients. Eleven additional patients were studied prospectively after initiation of MTX therapy. All showed significant decreases in spontaneous IgM-RF synthesis, with declining IgM-RF:IgM ratios, including all of the 9 who were studied during the first 24 hours of treatment. The results indicate that MTX has rapid effects on IgM-RF synthesis, and this action might be associated with its therapeutic efficacy in RA.     

Electron microscopic morphology of immunoglobulin aggregates and their interactions in rheumatoid articular collagenous tissues

Immunoelectron microscopy for IgG and IgA was combined with plain electron microscopy and light microscopy to study a variety of articular collagenous tissues from 14 cases of classic rheumatoid arthritis. Numerous extensive aggregates of IgG and IgA positive material were found widely spread in locations that coincided with immunofluorescent staining for these immunoglobulins and B1c. This Ig positive material is thought to represent deposits of immune complexes. As great and greater amounts were seen in fibrocartilage menisci as in hyaline cartilage. A single specimen of disease tendon was also positive. Severe pathologic changes of the matrix characterized by loss of normal morphology, alterations in collagen, and overall reduced density were observed in regions of aggregate deposition with a consistent replacement and disappearance of collagen in the locale of the aggregates themselves. Polymorphonuclear cells in regions of degraded hyaline and tendon matrix were seen to have phagocytosed aggregates. These data give some credence to a direct role of immune aggregates in rheumatoid arthritis articular collagenous tissues in disease pathogenesis.     

The effect of long-term methotrexate therapy on hepatic fibrosis in rheumatoid arthritis

Objective. To evaluate the progression of hepatic fibrosis in patients with rheumatoid arthritis (RA) treated with methotrexate (MTX). Methods. Fifteen patients receiving MTX for RA were prospectively studied by electron microscopic analysis of biopsy specimens. Results. Five of the 15 patients had evidence of increased hepatic collagen after 2 years of MTX therapy. Conclusion. Hepatic fibrosis may progress in a subgroup of RA patients treated with MTX.     

Liver sinusoids and sinusoidal cells in patients with agnogenic myeloid metaplasia

The origin of sinusoidal portal hypertension often remains unknown in patients with agnogenic myeloid metaplasia. Four consecutive patients with agnogenic myeloid metaplasia had liver biopsies examined under light and electron microscopy. Two of the four had obvious clinical portal hypertension; of these two, only one had portal vein thrombosis. All four cases showed sinusoidal infiltration by myeloid cells (from very mild to obvious) and an increased perisinusoidal collagen network. Under electron microscopy we observed (a) the collagenization of the Disse space, (b) myeloid cells in the lumen and the Disse space, (c) the transformation of perisinusoidal cells into transitional cells, and (d) fragments of basement membrane-like material. It is possible that all these abnormalities, and not only sinusoidal infiltration, contribute to increase vascular resistance, even when there is no clinical evidence of portal hypertension unrelated to vascular thrombosis.     

Suppression of rheumatoid factor production by methotrexate in patients with rheumatoid arthritis. Evidence for differential influences of therapy and clinical status on IgM and IgA rheumatoid factor expression

Suppression of rheumatoid factor (RF) production in rheumatoid arthritis (RA) has been variably attributed to the use of remittive agents per se or to clinical improvement associated with their use. There have been conflicting reports with regard to the influence of methotrexate (MTX) on serum RF levels in RA. We determined IgM-RF and IgA-RF levels in paired serum samples (obtained at study entry and completion) from RA patients enrolled in multicenter trials with the Cooperative Systematic Studies of Rheumatic Diseases program. After exclusion of the 14 IgM-RF-negative sera, there were samples from 30 MTX-treated patients and 52 placebo-treated patients. Changes in IgM-RF and IgA-RF levels were weakly associated with each other. Significant decreases in IgM-RF levels were observed in the MTX-treated patients, but not in the placebo group. These changes were most significant in the MTX-treated patients who improved clinically. There were significant decreases in IgA-RF levels at study completion among MTX-treated patients who had improved clinically and those who had not improved clinically, but not in the placebo group. The contributions of clinical improvement and MTX treatment to changes in serum IgM-RF and IgA-RF levels were examined using a logistic regression model. Changes in IgM-RF were strongly related to MTX treatment and, to a lesser extent, to clinical improvement; changes in IgA-RF were related only to MTX treatment. These results indicate that MTX treatment per se decreases both IgM-RF and IgA-RF levels, whereas clinical improvement correlates with decreased IgM-RF levels only.(ABSTRACT TRUNCATED AT 250 WORDS)     

Efficacy and safety of 10-deazaaminopterin in the treatment of rheumatoid arthritis: A one-year continuation,double-blind study

Objective. To determine the long-term safety and efficacy of 10-deazaaminopterin (10-DAM) in the treatment of rheumatoid arthritis (RA). Methods. A 1-year continuation of an initial 15-week randomized, double-blind clinical trial of 10-DAM and methotrexate (MTX). Results. 10-DAM (n = 10) and MTX (n = 8) had comparable safety and efficacy profiles. One 10-DAM—treated and 2 MTX-treated patients experienced transient side effects; 1 MTX-treated patient experienced recurrent nausea and discontinued MTX. Conclusion. 10-DAM appears to be as beneficial and as safe as MTX for the treatment of RA.     

Low-dose methotrexate compared with azathioprine in the treatment of rheumatoid arthritis. a twenty-four—week controlled clinical trial

Forty-two patients with definite or classic rheumatoid arthritis entered a prospective 24-week, double-blind, parallel clinical trial, followed by an 18-month open phase. All subjects had active synovitis that was unresponsive to nonsteroidal antiinflammatory medications and conventional slow-acting antirheumatic drugs. Initial treatment with azathioprine (AZA), 100 mg/day, or methotrexate (MTX), 10 mg/week, orally, was adjusted at predefined intervals. Both treatment groups showed statistically significant improvement at week 24, compared with baseline status, in all 9 clinical outcome variables. There were no apparent statistically significant differences in these outcome variables between the 2 treatment groups. There was a trend toward a more marked and rapid improvement in the MTX-treated group. Radiologic evidence of progression of joint damage was similar in both treatment groups at 24 and 52 weeks. Four of the 42 patients (2 receiving MTX and 2 receiving AZA) discontinued the study because of side effects, and 1 MTX-treated patient withdrew because of personal reasons. Outcome measures at week 52 (open phase) were not statistically different from those at week 24. Twenty-three patients were still taking the medication at week 104. We found that AZA and MTX were similarly effective in the treatment of rheumatoid arthritis, and that this beneficial effect was maintained for up to 2 years in most patients.     

Low-dose methotrexate compared with azathioprine in the treatment of rheumatoid arthritis. A twenty-four-week controlled clinical trial

Forty-two patients with definite or classic rheumatoid arthritis entered a prospective 24-week, double-blind, parallel clinical trial, followed by an 18-month open phase. All subjects had active synovitis that was unresponsive to nonsteroidal antiinflammatory medications and conventional slow-acting antirheumatic drugs. Initial treatment with azathioprine (AZA), 100 mg/day, or methotrexate (MTX), 10 mg/week, orally, was adjusted at predefined intervals. Both treatment groups showed statistically significant improvement at week 24, compared with baseline status, in all 9 clinical outcome variables. There were no apparent statistically significant differences in these outcome variables between the 2 treatment groups. There was a trend toward a more marked and rapid improvement in the MTX-treated group. Radiologic evidence of progression of joint damage was similar in both treatment groups at 24 and 52 weeks. Four of the 42 patients (2 receiving MTX and 2 receiving AZA) discontinued the study because of side effects, and 1 MTX-treated patient withdrew because of personal reasons. Outcome measures at week 52 (open phase) were not statistically different from those at week 24. Twenty-three patients were still taking the medication at week 104. We found that AZA and MTX were similarly effective in the treatment of rheumatoid arthritis, and that this beneficial effect was maintained for up to 2 years in most patients.     

Pyrophosphate arthropathy: a clinical and radiological study of 105 cases.

105 consecutive patients who presented to a rheumatologist because of joint disease and who also had evidence of deposition of calcium pyrophosphate dihydrate (CPD) were studied clinically and radiologically. There were 76 women (mean age 73) and 29 men (mean age 62). Of only 18 patients below the age of 60 at presentation 12 were men. The majority of the younger male group suffered from acute attacks of synovitis, and had no clinical or radiological evidence of joint damage. In contrast the older female group had widespread destructive changes. Associated joint disease included generalised osteoarthritis (45), rheumatoid arthritis (8), joint hypermobility (13), previous knee surgery (8), and gout 92). Sixteen patients had received long-term steroid therapy. Severe destructive joint changes were seen in 16 patients. The radiological features in those with rheumatoid arthritis by ARA criteria were atypical. The relationship between CPD deposition and arthritis is discussed in the light of these findings.     

Detection of Luse bodies, spiralled collagen, dysplastic collagen, and intracellular collagen in rheumatoid connective tissues: an electron microscopic study.

BACKGROUND--Rheumatoid arthritis is a chronic inflammatory disease leading to alterations of the extracellular matrix in tendons, ligaments, and cartilage. The structural changes of the collagenous systems in rheumatoid connective tissues are largely unknown, however. METHODS--Thirty four samples of menisci, 36 cruciate ligaments, and four tendons were taken during joint surgery in patients with rheumatoid arthritis. Eighteen menisci, 35 ligaments, and 30 tendons obtained at necropsy served as a control group. The extracellular matrix in the two groups was analysed by the combined use of transmission and scanning electron microscopy, immunohistochemistry with monoclonal antibodies recognising collagen types IV and VI, and ultramorphometry. RESULTS--Normal tendons and ligaments predominantly showed a unidirectional fibril arrangement. Whereas type IV collagen showed a positive staining pattern along all basement membranes, type VI collagen formed fine, filaments aligned in parallel. In patients with rheumatoid arthritis a significant reduction of the mean diameter of the collagen fibrils was found owing to the presence of thin collagenous fibrils 20-60 nm in diameter. Most of these fibrils showed considerable changes in their arrangement with irregular courses (so-called interfibrillar dysplastic collagen). Up to 410 nm thick frayed fibrils with irregular outlines (spiralled collagen) and intracellular collagen forms were found in rheumatoid tissues. In addition, atypical thick collagenous structures with 41 nm periodicity (Luse bodies) were detected in the matrix. The upregulation of type IV collagen in rheumatoid arthritis was associated with an increase in the vascular density. The expression of type VI collagen was upregulated in fibrotic zones. CONCLUSIONS--The dramatic ultrastructural collagen changes lead to a structural and functional insufficiency of the extracellular matrix in rheumatoid connective tissues. The results suggest that collagen alterations may contribute to the development of tendon and ligament ruptures in rheumatoid arthritis.     

Ultrastructural localization of type IV collagen and laminin in the Disse space of rat liver with carbon tetrachloride induced fibrosis

Monospecific antibodies, directed against type IV collagen and laminin, were used to clarify the process of sinusoidal capillarization in rats after carbon tetrachloride (CCl4) intoxication by the direct immunoperoxidase method. After acute intoxication, both type IV collagen and laminin were increased in the area of hepatic necrosis, adjacent to the central veins; however, sinusoidal capillarization was not found. During chronic intoxication, deposition of laminin was co-distributed with that of type IV collagen, but deposition proceeded more slowly than that of the type IV collagen. Deposition of laminin was increased in the Disse space. Sinusoidal capillarization was noted as thick deposition of both antigens by light microscopy. Immunoelectron microscopy showed that both components were continuously present in the Disse space. Intracellularly, both antigens were found in the rough endoplasmic reticulum (RER) of fat-storing cells (FSC) and endothelial cells, and these cells showed morphological changes, becoming slender and flattened. In contrast, few immunoreactive products of the two components were observed in the hepatocytes. These findings suggest that type IV collagen and laminin are indispensable for the establishment of sinusoidal capillarization, and that FSC play an important role in the production of both components.     

Effect of methotrexate therapy on bone mineral density and body composition in rat adjuvant arthritis

OBJECTIVE: To test whether methotrexate (MTX) therapy of rat adjuvant arthritis (AA) prevents loss of bone mineral density (BMD) and loss of adipose and lean body mass compared to pair-fed controls with untreated rat AA (positive controls) and rats without AA (negative controls). METHODS: AA was induced by a Mycobacterium butyricum injection at the base of the tail of 5-week-old female Lewis rats. The MTX-treated group was injected with adjuvant and then treated twice weekly with MTX (1.0 mg/kg/wk intraperitoneally). To control for the effects of AA on appetite and weight, food given to control animals and MTX-treated rats with AA was limited to that consumed by rats with untreated AA. At 42 days post-adjuvant injection, the animals were sacrificed and tibial BMD was measured. Body composition was analyzed for percentage fat, protein, ash, and water. RESULTS: There was no difference in ankle edema score or ankle width between the negative controls and MTX-treated group at necropsy. BMD was significantly higher in the negative controls versus positive controls and MTX-treated and in MTX-treated versus positive controls. There was significantly less body fat and protein and greater body water in the positive controls and MTX group compared to the negative controls. CONCLUSION: MTX prevents loss of BMD in the tibia in the rat AA model compared to positive controls. While MTX is effective in lowering inflammation in rat AA, there are still significant losses in BMD and body composition, which may have implications for rheumatoid arthritis.     

Liver histology in rheumatoid arthritis patients receiving long-term methotrexate therapy. A prospective study with baseline and sequential biopsy samples

Twenty-nine patients with active rheumatoid arthritis receiving long-term oral weekly methotrexate (MTX) therapy were studied to determine the extent of their hepatic architectural changes. Liver biopsies (n = 101) were performed in all patients before the initiation of MTX therapy, after 2 years, and annually thereafter (mean duration of therapy 53 months). The hepatic histologic grade (5-point scale) in 25 patients increased (worsened) (mean +/- SEM change 0.84 +/- 1.02; P = 0.001). Fibrosis, confirmed by trichrome staining, developed in 14 of 27 patients (52%). A history of alcohol consumption prior to starting MTX correlated significantly with subsequent worsening of the liver biopsy grade (r = 0.55, P = 0.0054). Alcohol intake prior to study entry, elevated weight at MTX initiation, and dose and duration of MTX were significantly associated with the development of fibrosis. Elevations in serum aspartate aminotransferase levels at 29-53 months of therapy correlated with the increase in hepatic histologic grade at the 3-year biopsy (r = 0.50, P = 0.04) and 4-year biopsy (r = 0.58, P = 0.03). We conclude that long-term MTX therapy in rheumatoid arthritis patients results in a statistically significant worsening in hepatic histologic grade, with common development of mild fibrosis. We do not consider these changes to be clinically significant at present.     

Suppression of collagen-induced arthritis by combination cyclosporin A and methotrexate therapy

Louvain (LOU) rats were administered either methotrexate (MTX; 0.3 mg/kg/week or 0.8 mg/kg/week intraperitoneally), cyclosporin A (CSA; 4 mg/kg/day or 10 mg/kg/day continuous infusion via osmotic pump), or a combination of both agents. The rats were immunized with native type II collagen (CII) to determine the effects of these agents on collagen-induced arthritis, an animal model of rheumatoid arthritis. A significant decrease in the incidence (P less than 0.01) and severity of arthritis by clinical (P less than 0.05) and radiographic assessments (P less than 0.05) was found in recipients of combination therapy, compared with controls. Delayed-type hypersensitivity reactions to CII were measured on day 26, and production of IgG antibody to CII was measured on days 7, 14, and 26. IgG antibody was evident by day 7, and titers were near-maximal by day 14. Both delayed-type hypersensitivity and antibodies to CII were reduced in animals that received the higher dosage of CSA. Liver, kidney, and spleen specimens obtained from rats treated with CSA and MTX demonstrated no histologic abnormalities on light microscopy, compared with controls. These studies indicate that CSA and MTX in combination is a safe and effective therapy for collagen-induced arthritis and may be useful in the treatment of rheumatoid arthritis.     

Membranous glomerulonephritis in rheumatoid arthritis unassociated with gold or penicillamine treatment.

A 16 year old girl with rheumatoid arthritis who had not received gold or penicillamine developed a nephrotic syndrome. Her renal biopsy specimen showed membranous glomerulonephritis by light, electron, and immunofluorescence microscopy.     

Mechanisms of Methotrexate Action in Rheumatoid Arthritis

Objective. To measure the effect of methotrexate (MTX) treatment in rheumatoid arthritis (RA) on the expression of synovial collagenase, stromelysin, and tissue inhibitor of metalloproteinase 1 (TIMP-1) gene expression in a prospective study. Methods. Serial percutaneous synovial biopsies (pretreatment and after 3–4 months) were performed on the knees of 8 patients (7 with RA, 1 with seronegative arthritis) who were beginning oral MTX therapy. Synovial gene expression was determined by quantitative in situ hybridization using computer-assisted image analysis. Results. After therapy, patients had decreased joint counts, morning stiffness, and erythrocyte sedimentation rates. Synovial inflammation in the biopsy tissues was slightly decreased after therapy. In situ hybridization on pretreatment and posttreatment frozen sections was performed to quantify synovial messenger RNA (mRNA) levels. Collagenase gene expression significantly decreased after MTX therapy (P = 0.006) even though cell density in the region was unchanged. TIMP-1 and stromelysin mRNA levels were not changed by MTX therapy. To study the mechanism of MTX action in vitro, MTX-treated and control fibroblast-like synoviocytes were stimulated with interleukin-1β (IL-1β). MTX did not alter collagenase or TIMP-1 mRNA levels after IL-1 exposure. Conclusion. MTX therapy decreases collagenase gene expression but not TIMP-1 or stromelysin gene expression in the synovium. This action is probably an indirect effect due to an alteration in the synovial cytokine milieu, rather than a direct effect on gene expression.