Rheumatoid arthritis: relation of serum C-reactive protein and erythrocyte sedimentation rates to radiographic changes

Therapeutic progress--review VI. Treatment of rheumatoid arthritis

Anti-rheumatic drugs used in rheumatoid arthritis fall into two distinct groups: non-steroidal anti-inflammatory and second-line drugs. Non-steroidal anti-inflammatory drugs give early symptomatic improvement and reduce the degree of acute inflammatory synovitis. Second-line drugs such as gold or D penicillamine exert an anti-inflammatory effect only after two to three months and act by suppressing disease activity: these reduce the ESR and other acute phase responses. However, the evidence that any of these drugs halt the progression of radiological changes or can be used as long-term agents to control the disease over a period of years is weak. The current use of anti-rheumatic drugs follows a general pattern with non-steroidal anti-inflammatory drugs used alone in patients with mild disease, whereas patients with severe disease also receive second-line drugs. As yet the long-term effect of this policy is not known. Cytotoxic drugs should be restricted to patients with severe disease who either fail to respond to conventional second-line drugs or have active extra-articular disease, particularly those with vasculitis.

C-reactive protein in childhood dermatomyositis

Serum levels of C-reactive protein (CRP) were determined in 9 patients with childhood dermatomyositis. Four children were seen during clinical relapse and all had serum CRP levels less than 1 mg/l. In addition direct immunofluorescent staining of muscle biopsies from 4 patients showed no evidence of CRP deposition in muscle tissue. Such patients appear to be able to produce CRP in response to acute infections, and it is suggested therefore that the pathological process in childhood dermatomyositis may not induce a significant CRP response.

Serum levels of C-reactive protein in Crohn's disease and ulcerative colitis

Prospective measurements were made of serum C-reactive protein levels and erythrocyte sedimentation rate in sixty-four patients with Crohn's disease and fifty with ulcerative colitis. The results were related to clinical assessment of disease activity. C-reactive protein levels were raised in both groups but were significantly higher in Crohn's disease than ulcerative colitis for all categories of disease severity: with mild disease the median and range of C-reactive protein concentration were 4, 0-65 mg/l in Crohn's disease v. 0, 0-15 mg/l in ulcerative colitis, P less than 0.01; in moderate disease the values were 15, 1-100 mg/l v. 3, 0-29 mg/l respectively, P less than 0.05 and in cases of severe disease, 85, 15-183 mg/l v. 12, 2-33 mg/l respectively, P less than 0.001. Erythrocyte sedimentation rate was also higher in Crohn's disease but did not closely reflect disease activity in individual patients. C-reactive protein levels corresponded closely with clinical and pathological indices of relapse, remission and response to therapy in patients with Crohn's disease. The precise assay of serum C-reactive protein provides an objective criterion of inflammatory activity, which may be useful in the assessment, management and study of Crohn's disease.

C-reactive protein in juvenile chronic arthritis: an indicator of disease activity and possibly amyloidosis

C-reactive protein (CRP) was found to be particularly high early in the course of those cases of juvenile chronic arthritis (JCA) with a systemic onset, the mean level being 12 mg/dl (120 mg/l). It was also raised in cases with a polyarticular onset, mean level 6 mg/dl, while in cases with a pauciarticular onset it was associated with only a modest increase up to 1.5 mg/dl (15 mg/l). At the onset of disease there was a good correlation with the erythrocyte sedimentation rate (ESR). Regression of systemic disease was associated with a steady fall in C-reactive protein, but those patients who developed amyloidosis within 5 years from onset had persistently high values until cytotoxic therapy was introduced. Patients who developed amyloidosis later tended to have high CRP levels in the months or even years before diagnosis. In a few patients with polyarthritis the CRP appeared to reflect severe disease more closely than their relatively low ESR.

Relationship between urinary sialylated saccharides, serum amyloid A protein, and C-reactive protein in rheumatoid arthritis and systemic lupus erythematosus

The urinary excretion of sialic-acid-containing oligosaccharides, total sialic acid, serum amyloid A protein (SAA), and C-reactive protein (CRP) has been studied in 48 patients with rheumatoid arthritis (RA) and in 17 patients with systemic lupus erythematosus (SLE). Linear regression analysis revealed a close positive correlation between serum SAA and CRP levels in both RA (r = 0.71, p less than 0.001) and SLE (r = 0.86, p less than 0.001). The urinary excretion of sialyl lactose showed a positive correlation with the serum levels of SAA and CRP in RA (r = 0.45 and r = 0.45, respectively, p less than 0.01) but not in SLE (r = 0.05 and r = 0.10 respectively). Changes in serum total sialic acid levels paralleled those in CRP and SAA in RA as well as in SLE. Patients with very active RA had higher urinary sialyl oligosaccharide excretion (p less than 0.001), higher CRP levels (p less than 0.01), and higher SAA levels ( p less than 0.05) than those with moderately active disease.

Serum concanavalin-A binding in rheumatoid arthritis

A nephelometric assay of concanavalin-A binding of serum acute phase proteins (con-A binding) has been used in cross-sectional and sequential studies of disease activity in rheumatoid arthritis (RA). Con-A binding correlated well with blood viscosity, C-reactive protein, and other individual acute phase reactants in patients with active RA. Twenty-four patients were treated for 6 months with D-penicillamine and assessed clinically and seriologically. Clinical improvement was accompanied by significant falls in both C-reactive protein and con-A binding, although the serological changes did not always occur in parallel in individual patients. The advantages of this simple, cheap assay of acute phase proteins are discussed.

Erythrocyte sedimentation rate in women with different manifestations of joint disease

A comprehensive population study of women aged 44-46 was carried out in Göteborg, Sweden in 1974-75. The mean erythrocyte sedimentation rate (ESR) and the rate of high ESR values (defined as ESR greater than or equal to 30 mm) were higher in women with manifestations of joint diseases than in other women, the differences being statistically significant for women with swollen or deformed finger joints and symptoms from the wrists. Women with manifestations of active joint disease at the time of the examination had even higher ESR values, the differences being statistically significant also for women with symptoms from the finger joints. High ESR values were more common in women with a positive serological test for rheumatoid factor and joint manifestations indicating arthritis and osteoarthrosis. The "arthritis" and "osteoarthrosis" groups each included about one-third of the subjects with rheumatoid factor. It is concluded that although ESR values are moderately increased in subjects with different manifestations of joint disease, the vast majority of such subjects have ESR values less than 30 mm.

Solid phase radioimmunoassays for human C-reactive protein

Two new, rapid and sensitive radioimmunoassays for human C-reactive protein (CRP) have been established using antiserum coupled to magnetizable cellulose particles, which facilitate phase separation. A single antibody method, using solid phase anti-CRP, provides a sensitivity of 50 microgram/l with a 1-h incubation time and intra- and inter-assay coefficients of variation of 10%. A double antibody method, using fluid phase rabbit anti-CRP serum and solid phase sheep anti-rabbit IgG serum, provides a sensitivity of 3 microgram/l with an overnight incubation and intra- and inter-assay coefficients of variation of 10%. Among 468 sera from normal adult volunteer blood donors the median CRP concentration was 800 microgram/l, interquartile range 340-1700 microgram/l and range 70-29,000 microgram/l. Ninety percent of samples contained less than 3 mg/l and 99% less than 10 mg/l. Low levels (14-650 microgram/l) of CRP were detected both in amniotic fluids and in cerebrospinal fluids.

Relationship of the erythrocyte sedimentation rate to acute phase proteins in polymyalgia rheumatica and giant cell arteritis

We have compared the erythrocyte sedimentation rate (ESR) with other acute phase proteins (C-reactive protein (CRP), alpha(1) antitrypsin, orosomucoid, and haptoglobin) in 108 patients with polymyalgia rheumatica and/or giant cell arteritis. There was good correlation between CRP and ESR, but the ESR was also found to have the highest correlation with disease activity. The additional measurement of CRP or other acute phase proteins may be of value in a minority of cases.

Immune complexes in early arthritis. L Detection of immune complexes before rheumatoid arthritis is definite

Fifty-three patients with early arthritis were studied longitudinally for up to 3 years. During this time, 24 developed sufficient features for definite rheumatoid arthritis (RA) to be diagnosed. The other (arthralgia patients) differed from the RA patients as, in the majority, C-reactive protein and ESR were normal and anti-nuclear antibodies or rheumatoid factors were rarely found. Moreover, in time their signs and symptoms improved or disappeared. Circulating immune complexes were detected in both groups of patients by the platelet aggregation test whereas complexes detected by abnormal Clq-binding activity were found mainly in the RA patients. Platelet-aggregating complexes were usually present in the first samples studied and disappeared in the arthralgia patients with recovery from their symptoms. In the RA patients, Clq-binding complexes appeared simultaneously or later than platelet-aggregating complexes but both tests were positive several months before RA could be diagnosed. These results suggest that immune complexes are one of the first immunological abnormalities to appear in patients with arthritis. Although the constituent antigen and antibody of complexes detected by either test are unknown, their possible nature is discussed.

Plasma viscosity--a new appraisal of its use as an index of disease activity in rheumatoid arthritis

The suitability of the plasma viscosity (PV) test has been examined in relation to the more commonly used erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) estimations as a diagnostic aid in 120 outpatients with rheumatoid arthritis (RA) and as an index of improvement during subsequent specific antirheumatic drug treatment (60 outpatients). Correlation data based on 7 clinical variables suggest that PV estimations are at least as reliable as ESR and CRP in terms of diagnosis and as indices of improvement. The methodological advantages offered by the PV test lend support to its application in RA.

C-reactive protein fifty years on

The discovery of C-reactive protein (CRP) half a century ago led to the description of the acute-phase reaction which is a fundamental response of the body to injury. Recent work on the structure and function of CRP has revealed the existence of a unique plasma protein family, including CRP and serum amyloid P component (SAP). These proteins have been conserved throughout vertebrate evolution. CRP binds specifically to a wide range of substances derived both from damaged autologous cells and from microorganisms. Complexed CRP can activate the complement system and, by virtue of its dramatically increased production in response to tissue injury, it probably acts primarily as a protective mechanism. However, in some circumstances CRP may also initiate or exacerbate inflammatory lesions. Clinical measurement of serum CRP is valuable as a screening test for organic disease and as a sensitive object index of disease activity and response to therapy in some inflammatory, infective, and ischaemic conditions. SAP closely resembles CRP in structure but not an acute-phase reactant in man. An apparently identical protein, amyloid P component (AP), is always found in amyloid deposits. AP is also found in normal tissues, as an integral constituent of vascular basement membranes and is located on the peripheral microfibrillar mantle of elastic fibres throughout the body.

C-reactive protein in giant cell (cranial, temporal) arteritis

A controlled study of C-reactive protein in patients with and without temporal arteritis was performed. C-reactive protein was elevated in 10 of 11 patients with biopsy-proven temporal arteritis before treatment. It was positive in 14 of 32 control patients with negative temporal artery biopsies. This difference is statistically significant. C-reactive protein was elevated in 6 to 9 (depending on the adequacy of therapy) of 34 patients with temporal arteritis after corticosteroids were started. C-reactive protein and erythrocyte sedimentation rate are positively correlated in untreated arteritis. Clinical correlation showed C-reactive protein was more sensitive than the erythrocyte sedimentation rate in following the adequacy of corticosteroid dosages in temporal arteritis probably because many more noninflammatory factors influence erythrocyte sedimentation than influence C-reactive protein.

Plasma levels of beta 2-microglobulin in rheumatoid arthritis

A simple and inexpensive method is described for the determination of beta 2-microglobulin (beta 2-MG) by enzyme-amplified single radial immunodiffusion. The values obtained with this method correlate well with those determined by means of a commerical RIA kit. Using the immunodiffusion method we have measured the plasma levels of beta 2-MG in 135 patients with rheumatoid arthritis (RA) and normal serum creatinine levels. 33% of the patients had increased concentrations of beta 2 MG, but the levels were found to correlate poorly with the values of several variables generally used as indices of the degree inflammatory activity in RA. Furthermore, in contrast to earlier claims to the contrary, beta 2-MG correlated positively with age. The value of beta 2-MG in plasma as an index of inflammatory activity in RA is questioned.

Rheumatoid arthritis: effects of a new agent (ICI 55 897) on serum acute phase proteins and the erythrocyte sedimentation rate

Thirty-four patients with rheumatoid arthritis (RA) were treated with a new agent (ICI 55 897) in addition to basic therapy with nonsteroid anti-inflammatory drugs. Five patients had the drug for less than 28 days; the remaining 29 were observed for periods up to a year. At 140 days, when all but 2 patients were in the study, there had been statistically significant improvement in clinical score, serum C-reactive protein, erythrocyte sedimentation rate, and plasma fibrinogen. Thereafter results continued to improve but were biased because some patients had stopped taking the drug. The final conclusion was that 17 patients had improved with 1 late relapse, and 15 had not responded. Adverse effects were trivial except in 2 instances: one patient had a transient unexplained rise in blood urea, another had a haematemesis. Neither effect could be attributed with certainty to the drug. ICI 55 897 has no intrinsic analgesic or anti-inflammatory properties. We suggest the findings of this study indicate that this agent, with low toxicity and the ability to lower acute-phase protein levels, may be an alternative to gold or penicillamine in the treatment of RA.

C-reactive protein, ESR, and klebsiella in ankylosing spondylitis

Serum C reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured on 469 occasions in 149 patients with ankylosing spondylitis who had also been investigated for faecal carriage of klebsiella/enterobacter species on the same occasions. Raised values of CRP and ESR correlated with each other (P less than 0.001) as well as with clinically assessed active disease episodes (P less than 0.001). Patients with positive cultures for klebsiella were found to have higher mean values for CRP and ESR than those with negative cultures (P less than 0.025). CRP appears to be a useful marker of disease activity in ankylosing spondylitis.

Value of serum C-reactive protein measurement in the investigation of fever in systemic lupus erythematosus

The concentration of C-reactive protein (CRP) in the sera of patients with systemic lupus erythematosus (SLE) was higher when the disease was active than when it was inactive, but was only markedly raised in patients suffering from identifiable microbial infection. CRP levels greater than 60 mg/l suggest the presence of intercurrent infection and may therefore be a valuable aid to the differential diagnosis of pyrexia in SLE.

An evaluation of serum protein profiles in the long-term surveillance of prostatic cancer

Longitudinal and vertical studies on prostatic cancer have confirmed that many forms of oestrogen therapy have a profound effect on the levels of several acute phase reactant proteins (APRP). This action overrides any response of the APRPs to a rising tumour load. However, serum C-Reactive protein and albumin levels appear to be independent of oestrogen control and their respective rise and fall is associated with tumour progression even when the patient is saturated with oestrogens.

Controversies regarding giant cell (temporal, cranial) arteritis

It is important to establish the diagnosis of temporal arteritis because the disease is treatable; treatment may prevent blindness and even death. Temporal arteritis usually occurs in people older than 51 years of age, although very rarely, histologically documented disease occurs in younger people. The onset may be occult, so that there are few findings. A multitude of signs and symptoms may occur such as fever, headaches, malaise, weight loss, anemia, stroke, cranial nerve palsies, polymyalgia rheumatica, aortitis and other large vessel involvement. The eye may suffer from ischemic optic neuropathy (anterior or posterior), central or cilio-retinal arterial occlusion, ophthalmic artery ischemia, or extraocular muscle palsies. An arterial biopsy showing giant cell arteritis establishes the diagnosis. However, a negative biopsy does not rule out the disease because of the occasional presence of skip areas. Arteriography has only rarely yielded a positive temporal artery biopsy when the initial biopsy done elsewhere was negative. As a diagnostic parameter, the erythrocyte sedimentation rate is nonspecific, being elevated in diseases other than temporal arteritis and sometimes being falsely lowered by technical factors. Furthermore, the temporal artery biopsy is occasionally positive despite a normal erythrocyte sedimentation rate. Treatment is aimed at relieving the patient's symptoms and normalizing the erythrocyte sedimentation rate. Because of the wide spectrum of clinical and laboratory finding in temporal arteritis, no one specific treatment regimen with systemic corticosteroids works for all patients. Temporal arteritis is a well known disease of the elderly which ir rarely fatal but results in significant visual morbidity (Hinzpeter & Naumann, 1976; Spencer & Hoyt, 1960). Since Hutchinson's (1890) description, more than a thousand articles have been written on the subject (Cohen & Smith, 1974). Despite this, many unanswered questions and controversies remain concerning the diagnosis, prognosis and treatment of temporal arteritis. My goal is to review these questions and areas of controversy.

Relationship between erythrocyte sedimentation rate and serum C-reactive protein in rheumatoid arthritis

Serum C-reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) were compared in 241 patients with rheumatoid arthritis (RA). There was a positive linear correlation between the 2 measurements with a high degree of variability. Neither age nor duration of RA had a detectable influence. The relationship between CRP and ESR was, however, altered by treatment with gold, penicillamine, or high doses of prednisone. It is suggested that serum CRP is the more sensitive measurement, but that CRP and ESR do not have identical clinical significance.

Effects of gold, dapsone, and prednisone on serum C-reactive protein and haptoglobin and the erythrocyte sedimentation rate in rheumatoid arthritis

Sequential measurements of serum C-reactive protein (CRP), serum haptoglobin (Hp), and erythrocyte sedimentation rate (ESR) were made in 209 patients with rheumatoid arthritis (RA); 78 of them were treated with gold, 71 with dapsone, and 60 with prednisone. The results were expressed as proportional changes in the measurements at 28-day intervals after treatment began. The period of study was 140 days. During treatment with gold and dapsone there were statistically significant gradual and progressive falls of similar magnitude in serum CRP and ESR. During treatment with prednisone serum CRP and ESR fell abruptly by 28 days and thereafter altered little. At 140 days prednisone had had the largest proportional effect on both measurements. During gold treatment the fall in serum Hp was similar to that of the ESR. In contrast, prednisone had little effect on Hp levels despite large falls in serum CRP and the ESR. Either prednisone stimulates Hp synthesis or the divergence is an expression of the difference in type of effect between gold and prednisone on RA. The effect of dapsone on serum Hp was large and progressive; it partly reflects haemolysis and, since the haemolysis was not progressive, partly improvement in the RA. The results show the relative efficacy of the drugs and suggest that dapsone may be a useful alternative treatment for RA.

Prognosis in rheumatoid arthritis. A longitudinal study of newly diagnosed younger adult patients

The course of rheumatoid arthritis was analyzed in 50 newly-diagnosed adults followed prospectively for an average of over five years. Eighteen patients had no swelling and no erosion (outcome 1), 22 patients had swelling without erosion (outcome 2) and 10 patients had erosion (outcome 3). Computer-assisted data screening and multivariate analytic technics were employed to derive a simple index from entry data which correlated closely with the patients' subsequent articular course. The index included six entry items: positive rhematoid factor; two or more swollen upper extremity joints on examination (2 points each); history of Raynaud's-like symptoms; malaise or weakness at the onset of arthritis; white race and female sex (1 point each). This index was 80 per cent accurate over-all in classifying patients into the three mutually exclusive articular outcome categories. Zero to 2 points on entry predicted no swelling, 3 to 5 points swelling without erosion and 6 to 8 points the development of bony erosion. Although results must be qualified to this patient population in the early stages of disease, the analytic approaches developed promise to assist with a broad range of clinical research and medical care delivery problems.

Salazopyrin in rheumatoid arthritis

After a 12-week preliminary period of observation 32 patients with consistently active rheumatoid arthritis (RA) were treated for up to 22 weeks with salazopyrin. Seven patients could not tolerate the drug. The remaining 25 patients had a marked improvement in subjective clinical state and significant falls in serum C-reactive protein and the erythrocyte sedimentation rate 6 weeks after treatment began. The improvement was maintained after 22 weeks. The results strongly suggest that further trials with this drug in RA are needed.

Comparative clinical study of protein SAP (amyloid P component) and C-reactive protein in serum

The serum concentration of protein SAP (amyloid P component) has been measured for the first time in a substantial series of normal individuals and patients with various diseases, and the results contrasted with the levels of the related protein C-reactive protein (CRP). The mean +/- s.d. concentration of protein SAP was 43 +/- 14 microgram/ml in seventy-six normal men, 33 +/- 10 microgram/ml in eighty-six normal women and 4 +/- 2 microgram/ml in thirty-six normal cord sera. Unlike CRP, whick is a major acute phase reactant, protein SAP was only slightly elevated in inflammatory and neoplastic diseases in which CRP was greatly increased. The level of protein SAP was significantly depressed in patients with hepatic disease, suggesting that its measurement might be of value in their management.

Soft tissue radiography for evaluating clinical activity of rheumatoid arthritis

The value of soft tissue radiography in assessing the activity of rheumatoid arthritis was investigated in 67 patients and correlated to the clinical activity of the disease. Soft tissue radiography using a technique for mammary radiography was combined with immersion. Radiologically demonstrated periarticular oedema was most closely correlated to clinical activity. A close correlation also existed between soft tissue radiographic lesions and 99Tcm accumulation in hands.

Chloroquine treatment in rheumatoid arthritis. Correlation of clinical response to plasma protein changes and chloroquine levels

15 patients with active RA were observed over a 3-month period after starting chloroquine treatment. Clinical condition, plasma levels of chloroquine and levels of 15 individual plasma proteins were checked monthly. Nine patients responded favourably to therapy, 6 failed to respond. The responders had lower initial CRP, orosomucoid and ceruloplasmin levels, whereas their IgA and IgM levels were slightly elevated. Significant reductions in the levels of CRP, haptoglobin, orosomucoid, fibrinogen and ceruloplasmin occurred in the responder group of patients. Alfa1-antitrypsin, antichymotrypsin C3 and C4 levels within the normal range were frequently encountered despite other clear-cut signs of activity. The chloroquine levels did not differ between responders and non-responders, the mean concentrations being 1.04 and 1.6 micromol/l respectively. This study has also demonstrated that in selected cases, despite active joint disease, all acute phase proteins may be normal. Finally, it was obvious that chloroquine, even when inducing remission, only brought about a partial normalization of the plasma protein pattern.