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

Abstract

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 Iysosomes, 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.Methotrexate (MTX) is an effective agent in the treatment of refractory rheumatoid arthritis (RA) (1-lo), but there are concerns about its long-term use. The potential for toxic effects involving the pulmonary (11-15) and hepatic (16-19) systems have been documented. Risk factors for the development of hepatotoxicity have been well defined in patients with psoriatic arthritis (16,2&22); these factors include a history of alcohol abuse, obesity, and advanced age at the time of initiation of MTX therapy.We have previously examined multiple variables that assess the progression of hepatic abnormalities in liver biopsy specimens from patients with RA who have been taking MTX, and we have found similar risk factors in this population (23). Although the incidence of cirrhosis in patients receiving MTX for psoriatic arthritis is high (16,(20)(21)(22), the frequency of serious hepatotoxicity occurring in patients receiving the drug for treatment of RA is quite low (16)(17)(18)(19)(23)(24)(25)(26). In an earlier study using light microscopy (LM) to examine liver biopsy samples, however, we observed the beginnings of fibrotic changes in samples from 56% of the RA patients who had taken MTX for a mean period of 53 months (23).To determine whether the changes that are detectable by electron microscopy (EM) are more sensitive indicators of the beginning of hepatic abnormalities in RA patients, we examined sequential liver biopsy specimens (obtained annually during treatment) with both LM and EM. Preliminary result...

Light and electron microscopic analysis of sequential liver biopsy samples from rheumatoid arthritis patients receiving long‐term methotrexate therapy followup over long treatment intervals and correlation with clinical and laboratory variables

“…We have previously reported on light and electron microscopic analysis of hepatic biopsy specimens over a mean period of -3.5 years of MTX therapy (1 1, 14). The present report expands and extends our observations on the same patients, who have continued to undergo regular sequential liver biopsies through a mean followup period of 8.2 years.…”

“…Correlations of the grading scores in the sequential biopsy samples examined by LM and EM with data derived (14).…”

“…The 93 biopsy specimens analyzed by EM were graded by 2 of the authors (GIK and NWK) on a scale of 0-4, for each of the following abnormalities: presence or amount of collagen in the perisinusoidal space (number of spaces showing any collagen, number of fibrils, size of fibrils, proximity to portal zone or central vein, relation to bends in the sinusoids), presence or amount of neutral fat droplets in hepatocytes (number of droplets, size of droplets, relative hepatocyte volume filled by fat droplets), increases in secondary and tertiary lysosomes in hepatocytes (as evidence of bile stasis) (18), and increases in smooth endoplasmic reticulum (SER). The details of this system have been described previously (14,19).…”

Rheumatoid Arthritis in the Aged

“…Transient elevations of liver enzymes occur frequently, but their long term significance is unclear, since they do not correlate with histological abnormalities. Moreover, sequential liver biopsies in patients continuing methotrexate therapy showed no evidence of progression of abnormalities in hepatic architecture (Kremer et al 1991;Sawitzke et al 1991;Scully et al 1991). Moreover, sequential liver biopsies in patients continuing methotrexate therapy showed no evidence of progression of abnormalities in hepatic architecture (Kremer et al 1991;Sawitzke et al 1991;Scully et al 1991).…”

Anaesthesia and rheumatoid arthritis

“…This consists of progressive hypoxaemia associated with interstitial and alveolar infiltrates and varying degrees of bronchiolitis and fibrosis [66,67]. Hepatic fibrosis may occur with low dose methotrexate therapy, but it is rare for this to have any significant clinical effect [68].…”