D. L. Scott

Fragmented fibronectin and other synovial fluid proteins in chronic arthritis: their relation to immune complexes

Fibronectin, an opsonic glycoprotein has been shown to exist in fragmented forms in serum and synovial fluid. Some fragments in synovial fluid appear to be polyethylene glycol (PEG) precipitable, suggesting incorporation into immune complexes (IC). PEG precipitation, SDS-PAGE and immunoblotting were used to determine whether PEG precipitable fragments are real or artefactual. Disease specificity of fragmentation and IC incorporation of fibronectin and other proteins were also studied using these techniques. PEG precipitable fragments do not appear to be artefactual, although some fibronectin fragments are cryoprecipitable. Protein fragments showed similar distributions in whole serum and synovial fluid, disease specific differences being confined to PEG precipitates. Rheumatoid arthritis (RA) synovial fluid PEG precipitates displayed the greatest array of fragmented immunoglobulins and fibronectin. No PEG precipitates contained albumin fragments. Protein fragments in IC may impair their effective removal from RA joints. Accumulated IC could lead to tissue damage via complement activation.

Cartilage degradation by polymorphonuclear leucocytes: in vitro assessment of the pathogenic mechanisms.

Polymorphonuclear leucocytes (PMNs), which predominate in inflammatory synovial fluid, can degrade cartilage. This was measured by a novel in vitro model; PMNs were incubated for up to one hour with 2 or 3 microns sections of cartilage and the glycosaminoglycan loss determined by microdensitometry after alcian blue staining. Glycosaminoglycan loss could be as a result of damage from reactive oxygen species, proteolytic enzymes, or a combination of the two. The relative contributions of these mechanisms were evaluated using selective inhibitors. The results show that activated PMNs will degrade cartilage and that this degradation is due to proteolytic enzymes and not reactive oxygen species. There is a specificity involving elastase but not other serine proteases. It is suggested that enzyme inhibition may play a part in reducing PMN mediated cartilage damage.

Increased DNA strand breaks in mononuclear cells from patients with rheumatoid arthritis.

Immune dysfunction is linked with lymphocyte DNA metabolism. In particular, DNA damage may impair lymphocyte function and induce increased cell turnover; such changes are of relevance to the pathogenesis of rheumatoid arthritis. The rate of DNA unwinding in alkaline solution was used as a measure of the number of DNA strand breaks in mononuclear cells freshly isolated from peripheral blood. The rate of DNA unwinding was significantly increased in cells from patients with rheumatoid arthritis compared with those from healthy subjects and from patients with other autoimmune and connective tissue diseases. These findings support the hypothesis that DNA damage is increased in patients with rheumatoid arthritis and it is one factor contributing to immune dysfunction in this disease.

Retinoblastoma in association with the chromosome breakage syndromes Fanconi's anaemia and Bloom's syndrome: clinical and cytogenetic findings

Two children presenting with sporadic unilateral retinoblastoma and exhibiting a high degree of chromosome breakage were noted to have unusual facies, microcephaly and abnormal skin pigmentation. In the first child the pattern of both spontaneous and mitomycin‐C‐induced chromosome breakage was characteristic of Fanconis anaemia although the degree of breakage was extreme. She also exhibited a striking increase in X‐ray‐induced chromosomal damage in G0 lymphocytes as measured by dicentric formation and increase in chromatid‐type aberrations. She had a number of typical clinical features, including cafe‐au‐lait patches and abnormalities involving the kidney; however, she demonstrated neither the hypoplasia of radius and thumb nor the typical aplastic phase of this disorder. At age 22 months the child became anaemic with trilineage myelo‐dysplasia, which was rapidly followed by the development of acute myeloblastic leukaemia. The early onset (at age 4 months) of retinoblastoma may have been associated with the underlying genomic instability. The second child exhibited a pattern of chromosome breakage characteristic of Blooms syndrome, in addition to a moderate increase in damage induced by mytomycin‐C. She had the typical stunted growth and malar hypoplasia of Blooms syndrome although she did not demonstrate the frequently described erythematous ‘butterfly rash’. Although patients with Fanconis anaemia and Blooms syndrome are recognised to be at an increased risk of cancer, retinoblastoma has not previously been described in patients with either condition. We suggest that underlying recessive chromosome breakage syndromes may be underdiagnosed in paediatric cancer patients, with important implications for prognosis and genetic counselling.

Protective effect of androgens against inflammation induced cartilage degradation in male rodents.

OBJECTIVES--Rheumatoid arthritis (RA) is a disease which predominantly affects women. Interestingly, low serum androgen levels and clinical improvement with androgen replacement have been reported in male patients. The aetiopathogenic role of sex hormones in arthritis and their potential long term effects on joint destruction and disability remains unclear, however. This study was designed to investigate the potential influence of sex hormones on inflammation induced cartilage degradation in male rodents. METHODS--An in vivo model of cotton wrapped cartilage implants was used to assess the effects of androgen, oestradiol, and progesterone on inflammation induced cartilage degradation, and in vitro techniques were used to investigate the direct actions on cartilage metabolism and cytokine production in male animals. RESULTS--Orchidectomy resulted in accelerated cartilage damage which was reversed by replacement of physiological levels of androgens. Granulomatous tissue from castrated male rodents produced higher amounts of interleukin 1. Sex hormones reduced spontaneous proteoglycan loss in vitro but did not interfere with the effects of interleukin 1 on cultured cartilage. CONCLUSIONS--Androgens appear to protect cartilage from inflammation induced breakdown in male animals. These results support a pathogenic role for hypoandrogenism in rheumatoid arthritis and suggest that long term androgen replacement may help prevent joint damage and disability.

What happens to patients with rheumatoid arthritis? The long-term outcome of treatment

We treat rheumatoid patients with various anti-rheumatic drugs, which are usually effective in randomised controlled trials; recommend surgery, which is often evaluated by prospective studies; and give physical t reatment and general advice, which has rarely been examined statistically. The trials are usually short term, lasting several weeks or months, with only a few lasting up to two years. But most patients with rheumatoid arthritis (RA) have a life-long disease. There is a need to define what happens in treated RA.

Lymphoedema of the limbs as an extra-articular feature of rheumatoid arthritis.

Seven patients with lymphoedema of the hands and arms, an unusual extra-articular feature of rheumatoid arthritis, are described. In all cases the lymphoedema persisted throughout follow up--in one case for more than five years--and was resistant to treatment with slow acting drugs, steroids, or cytotoxic agents. There was no correlation with severity of disease. It is concluded that the lymphoedema in these patients may be associated with reduced numbers of lymphatic vessels; increased capillary permeability or abnormal fibrinolysis may also be contributory factors. Conservative management of such patients is recommended.

Molecular forms of acetylcholinesterase in Hirschsprung's disease

We describe changes in the levels of different molecular forms of acetylcholinesterase in four cases of Hirschsprungs disease linked to the transition from aganglionic to normal bowel. In addition changes in a control case with histologically normal bowel is reported. In all patients with Hirschsprungs disease there is a marked increase in the level of the tetrameric form of the enzyme in the aganglionic region. The changing level of this form of the enzyme correlates well with the histochemical appearance suggesting that quantitative measurement of this molecular species might form the basis of an improved diagnostic test for the disease.

Can we develop simple response criteria for slow acting antirheumatic drugs

The conventional assessment of response to slow acting antirheumatic drugs depends on multiple clinical and laboratory measures. Each measure is analysed separately. For clinical practice and therapeutic trials a single unified classification of response is preferable, based on the most sensitive and simple current measures. Whether or not this was practical was determined in a prospective study of two cohorts of patients: 145 given penicillamine 250-500 mg daily in a single dose; 98 sulphasalazine at an initial dose of 500 mg rising after one month to 2 g daily. Both groups were followed up for 12 months. A panel of 11 clinical and laboratory measures were evaluated every three to six months. Most changes had occurred by six months, and this was the optimum time to classify response. Four measures were used to devise a five point (0-4) classification of response from no change to remission. The objective was to evaluate if this approach is appropriate; the best level of each measure to use was not determined. The response index was based on: erythrocyte sedimentation rate less than 30 mm/h; articular index less than 3; morning stiffness less than 15 min; greater than 50% reduction in joint pain. Similar results were obtained with both drugs. The other clinical and laboratory measures gave limited information. This response index is simple and appropriate. It is suitable for use in clinical practice and drug studies, though the optimal values for dividing each clinical and laboratory variable need to be determined.

The clinical value of measuring immunoglobulins when assessing penicillamine therapy in rheumatoid arthritis

SummaryImmunoglobulins are often high in active rheumatoid arthritis and fall when treatment with a slow-acting anti-rheumatic drug is instituted. We assessed the value of monitoring immunoglobulins during penicillamine therapy; 145 patients were followed for up to 5 years, IgA, IgM and IgG levels were compared to 12 other clinical and laboratory variables on 903 occasions. Mean levels of IgA and IgG fell by 10–30%. These changes were less than with ESR or clinical measures such as articular index and duration of morning stiffness. Immunoglobulin levels showed weak correlations with other variables. Only a small number of patients had hypogammuglobulineamia. Initially, 5 cases had low IgA with subsequent falls in 3 more. Initially, 2 cases had low IgG with subsequent falls in 5 more. No patients had low IgM levels. These changes seemed clinically irrelevant. Radiological progression was related to IgA levels. Patients with persistently high rates of radiological progression had persistently higher serum IgA. We conclude that IgM gives the most “acute phase” pattern of response. IgA gives more theoretically interesting information, especially concerning radiological progression. There is only a limited amount of clinically valuable information gained from measuring immunoglobulins.