Quantified neurological examination with emphasis on motor and sensory functions in patients with rheumatoid arthritis and controls

A controlled study of quantified clinical neurological examination, including psychophysical assessment of sensory thresholds, in patients with rheumatoid arthritis (RA) was carried out. Fifty-five women with seropositive RA living in North Norway and 83 healthy controls underwent clinical neurological examination quantified by neurological symptom score (NSS) and neurological deficit score (NDS). Vibration threshold (VT), warm-cold detection threshold (limen) as well as heat pain detection threshold (HPDT) were performed to evaluate afferent myelinated and unmyelinated fibre functions. Higher scores on NSS and NDS were seen in RA patients compared with the controls. Higher index finger and big toe VT was demonstrated in the patients, while results from warm-cold limen and HPDT were not significantly different in the two groups. Among the disease-related variables, the most prominent finding was a positive association of index finger VT with disease duration in the patients (P = 0.01). Maximum walking time (15 m) was a significant predictor of big toe VT in the patient group (P = 0.0001). This study suggests impaired peripheral nerve function in afferent myelinated fibres. However, involvement of dorsal column fibres cannot be excluded, although patients with radiological atlantoaxial subluxation were not included in this study.

Autonomic nervous system function in rheumatoid arthritis. A controlled study

OBJECTIVE

To study cardiovascular autonomic nervous functions in patients with rheumatoid arthritis (RA) compared with controls and to investigate fasting and meal stimulated pancreatic polypeptide (PP) in RA and its possible associations with autonomic functions and disease activity.

METHODS

Forty-three women meeting the American Rheumatism Association 1987 diagnostic criteria for RA and 61 healthy controls were studied. Blood pressure recordings and cardiovascular heart rate studies were performed. PP was measured by radioimmunoassay.

RESULTS

Cardiovascular reflexes were equal in the 2 groups, but the patients had significantly higher fasting plasma PP level with mean log10 value of 0.94 pmol/l (SD = 0.38) compared with 0.68 pmol/l (SD = 0.35) in the controls (p = 0.0006). Mean log10 plasma PP increase 30 min after the meal was 1.80 pmol/l (SD = 0.42) for the patient group and 1.47 pmol/l (SD = 0.40) in the controls (p = 0.0001). Feeding caused a mean PP increase of 1.85 (SD = 0.42) for the patients and 1.44 (SD = 0.42) in the controls 60 min postprandially (p = 0.0001). Multiple regression and correlation analysis showed no association between PP and disease activity.

CONCLUSION

The higher basal and postprandial PP in the RA group indicates a relationship between the disease and PP by unknown mechanisms.

Characterization of human serum amyloid A protein isoforms separated by two-dimensional electrophoresis by liquid chromatography/electrospray ionization tandem mass spectrometry

A detailed structural analysis of the serum amyloid A proteins (SAA) of an individual with highly active, chronic rheumatoid arthritis is reported. SAA isoforms were separated by high-resolution two dimensional (2-D) gel electrophoresis. Peptide mapping by reverse-phase chromatography/electrospray ionization tandem mass spectrometry was applied to correlate the protein(s) contained in each spot with their respective coding gene and to study the post-translational processing and modification events which might result in differential electrophoretic mobility. Nine protein spots were analyzed. The six major spots corresponded to the Arg and des-Arg forms of SAA1 alpha and SAA2 alpha, respectively, and to the glycosylated and nonglycosylated form of constitutive serum amyloid A protein (C-SAA). Two minor spots were identified as SAA1 alpha isoforms containing post-translational modifications. We suggest that these variants contained a gamma-N, N'-dimethylasparagine residue at position 83 and that one of them was additionally oxidized at Trp53 and Trp85. The ninth spot was shown to contain a mixture of SAA1 alpha and SAA2 alpha. To our knowledge, this is the first report in which analysis of peptides has been used to verify the presence of C-SAA in acute-phase serum. Furthermore, the data illustrate that extensive post-translational processing results in a structurally diverse class of acute-phase SAA proteins, which are derived from a small number of genes. Finally, the fast and conclusive technology used in this study promises to be generally useful for the comprehensive investigation of proteins at the level of the primary structure.

MRI of anatomical variants of the wrist in women

In the analysis of magnetic resonance (MR) images of the wrist joint, some structural variations may lead to misinterpretation. Our aim was to search for different anatomical variants and their MR characteristics on axial images. Two groups of patients with rheumatoid arthritis (thirty one) and carpal tunnel syndrome (sixty two), and a group of asymptomatic controls (fifty four) underwent bilateral MR axial wrist imaging from the metacarpal bases to the distal radiocarpal joint. The imaging techniques included spin echo (SE), turbo spin echo (TSE) and fast field echo (FFE) sequences, using 3 mm-slice thickness. Different anatomical variants including hypoplasia of the hamulus or hook of the hamate bone (4 cases), anomalous muscles (lumbricals) inside the carpal tunnel (2 cases), unusual location (5 cases) and double branching of the median nerve (14 cases), and aberrant median artery (one case) were detected. These variants, if unfamiliar to MR readers, may be misinterpreted as pathological features.

[Classification of amyloidosis]

Amyloidosis is a collective term for a heterogeneous group of disorders characterized by deposition of a fibrillar, proteinaceous material, amyloid, in various tissues and organs. Increasing knowledge about the different proteins that constitute the amyloid fibrils has made it possible to classify amyloidosis by the fibril protein, which appears more rational than the traditional classification by its clinical symptoms. A group of experts on amyloidosis met in Oslo in 1990 and agreed upon a nomenclature and classification based on the chemical properties of the amyloid fibrils.

Bilateral fast MR imaging of the rheumatoid wrist

To evaluate the structural changes in the carpal tunnel and possible intrinsic median nerve damages in RA patients, quantitative bilateral magnetic resonance imaging (MRI) of the wrists was performed by means of a fast imaging sequence. Thirty-three women with RA and 42 controls were examined. The length of the carpal tunnel, the carpal tunnel volume/wrist volume (CTV/WV) ratio and the signal intensity of the nerve were calculated in both groups, bilaterally. The CTV/WV ratio was 0.12 in the patients and 0.11 in the control group (p = 0.007). A negative association was found between disease duration and carpal tunnel volume/wrist volume ratio (p = 0.049). Mean distal latency in the right motor median nerve was 3.0 +/- 0.4 msec (patients) and 3.4 +/- 0.6 msec (controls) (p = 0.002). Mean values in the right sensory branch were 1.2 +/- 0.1 msec (patients) and 1.4 +/- 0.3 (controls) (p = 0.01). The lack of association between the size of the carpal canal and neurophysiological parameters found in this study may suggest a possible protection of the median nerve by the increased canal size in patients with RA.

Brefeldin A inhibits experimentally induced AA amyloidosis

OBJECTIVE

Brefeldin A, an antibiotic with effects on certain intracellular compartments, was tested on murine secondary AA amyloidosis. Effects on splenic proteoglycan metabolism were analyzed along with plasma serum amyloid A (SAA) levels.

METHODS

Brefeldin A was administered daily to mice undergoing inflammatory stimulation with complete Freund's adjuvant to induce reactive AA amyloidosis. AA amyloid deposition was assessed using histochemistry, immunohistochemistry, and electron microscopy. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting were used to detect SAA in acute phase serum. Relative (semiquantitative) measurements of total SAA levels were obtained by densitometry of stained gels. Splenic proteoglycan metabolism was analyzed in treated animals and compared to untreated individuals by in vivo 35S administration during amyloid fibrillogenesis.

RESULTS

Based on (immuno)histochemistry and electron microscopy, animals undergoing drug treatment did not develop splenic amyloidosis, whereas the control animals exhibited massive amyloid fibril deposits in the spleen (p < 0.001). SAA was detected at roughly equal quantities in serum from both groups. No significant qualitative or quantitative difference in proteoglycan synthesis was found.

CONCLUSION

Brefeldin A seems to exert an inhibitory action on murine AA amyloidosis. It appears that the effect does not depend on the lack of fibril protein precursor nor altered proteoglycan synthesis.

Nerve conduction studies in rheumatoid arthritis

We performed a controlled study in search of possible differences in nerve conduction parameters in 52 patients with rheumatoid arthritis (RA) and 77 healthy controls. Nerve conduction studies (NCS) including recordings of motor and sensory amplitudes, the nerve conduction velocities and the distal latencies were investigated in both groups. The mean summed amplitude of compound muscle action potentials was 30.3 mV (SD = 7.9) in the patients compared with 35.9 mV (SD = 6.8) in the controls (p = 0.0001). Contrary to this, the mean values for motor distal latency was 14.3 msec (SD = 2.0) in the patients and 15.9 msec (SD = 1.8) in the controls (p = 0.0001). Decreased values for nerve conduction studies found in the patients may indicate impaired nerve functions in RA. However, the summed motor and sensory distal conduction were in fact better in the patient group.

Serum amyloid A protein in humans and four animal species: a comparison by two dimensional electrophoresis

Two-dimensional electrophoresis and N-terminal analysis were used to study serum amyloid A protein (SAA) from humans, mink, fox, goat and rabbit. Previously uncharacterized SAA variants were demonstrated in fox, goat and rabbit, and considerable interspecies homology was seen. In rabbit, two novel SAAs were characterized, and SAA1 and SAA2 were demonstrated in mink and rabbit sera. The results confirm previous cDNA studies and indicate that SAA do possess an important function also in fox and goat.

Quality of life in rheumatoid arthritis: a case-control study in patients living in northern Norway

OBJECTIVE

To study quality of life parameters in patients with rheumatoid arthritis and the possible association of these parameters with disease activity.

METHODS

Fifty-two women with rheumatoid arthritis and 52 controls completed two self reporting psychiatric screening tests: the General Health Questionnaire (GHQ - 30) and the Cantril Ladder scale. The number of psychiatric cases detected was not significantly higher for either group using the GHQ score S+ as the criterion.

RESULTS

Comparing the GHQ scores, patients showed a higher score compared with the controls (p = 0.02). The patients scored significantly higher on feelings of incompetance (p = 0.004), but not on the other subgroups of psychiatric factors. The patients reported lower life satisfaction on the Cantril self anchoring ladder (p = 0.0001). The functional capacity score was positively associated with the GHQ score. No association was detected between disease duration or the other disease activity parameters and either the GHQ score or the life satisfaction score.

CONCLUSION

This inconsistant relationship between clinical parameters and quality of life scores may be due to the fact that RA patients suffer from a chronic disease, or it may reflect an impaired psychosocial status in the patients. This study demonstrates that the increased psychological disturbances in women with RA is mainly explained by feelings of incompetance.

Quantitative cerebral MR in rheumatoid arthritis

PURPOSE

To determine the presence of hyperintense white matter lesions and atrophy reflecting cerebral vasculitis in rheumatoid arthritis.

METHODS

Thirty-three patients with rheumatoid arthritis and 48 control subjects were examined with MR. Mean age was 45.1 years (range, 26 to 55 years) for the patients and 42.2 years (range, 25 to 55 years) in the control group. To determine atrophy we measured the area of corpus callosum, the cerebrum, and the cerebellum on midline sagittal sections. On transverse images, the ventricle-to-brain ratio, the bifrontal ratio, and the bicaudate ratio were selected as atrophy parameters. Area and signal intensity were measured for the biggest and the smallest lesions in both groups.

RESULTS

Nine patients (27%) had hyperintense lesions compared with 15 (31%) of the control subjects. Mean numbers of hyperintense lesions were 1.3 in patients and 2.1 in control subjects. Mean area of the largest lesion in each patient was 27.4 mm2 for the patients and 29.8 mm2 in the control group. In patients with long disease duration (> 15 years) the mean ventricle-to-brain ratio was 0.09 compared with 0.08 in the control subjects. The midsagittal area of the cerebellum was 1349.8 mm2 in the patients with long disease duration and 1573.3 mm2 in the control group. No difference in number of hyperintense white matter lesions was detected between patients with long disease duration and the control subjects. Comparing the total group of patients with the control subjects, no significant differences in atrophy parameters or hyperintense white matter lesions were found. Also, there were no significant differences in relative signal intensity of the hyperintense lesions and corpus callosum between the two groups. We were not able to detect differences between treated versus untreated patients.

CONCLUSION

This study indicates a tendency of more cerebral and cerebellar atrophy in patients with severe rheumatoid arthritis. The number and size of the white matter lesions were not significantly different in the two groups and do not support a higher frequency of even clinically silent infarcts caused by vasculitis in the patients with rheumatoid arthritis compared with control subjects.

Purification and characterization of amyloid-related transthyretin associated with familial amyloidotic cardiomyopathy

Analysis of amyloid fibril material associated with familial amyloidotic cardiomyopathy revealed that it contains a mixture of transthyretin-related polypeptides. The major protein band in SDS/polyacrylamide gel corresponding to a molecular mass of 14.5 kDa, consists of transthyretin fragments starting at positions 46, 49 and 59, the latter not previously identified, and one blocked fragment derived from the N-terminal part of transthyretin. In reverse-phase HPLC, the major fragment recovered was that starting at Thr49, indicating a trypsin-like cleavage (Lys at position 48). Two minor bands, corresponding to 17 kDa and 35 kDa, contained proteins with blocked N-termini, and migrated as monomeric and dimeric transthyretin, respectively. A 13-kDa protein band was found to contain transthyretin with a ragged N-terminus, mainly starting at positions 2 and 5. Three more bands, corresponding to 10, 25 and 29 kDa, consist of transthyretin molecules with blocked N-termini and most likely of aggregates of truncated molecules. A point mutation of amyloid transthyretin was identified at position 111 (Met instead of Leu in normal serum transthyretin) which confirms the mutation found for Danish siblings with familial amyloidotic cardiomyopathy. However, the presence of a non-variant amyloid transthyretin was also observed, indicating that the Danish kindred is heterozygous with respect to this point mutation. Isoelectric focusing of the amyloid fibril material resolved multiple protein bands ranging over pH 4.5-6.5, confirming heterogeneities. Methanol extraction of the cardiac amyloid fibril material prior to the purification steps reveals a methanol-soluble substance amounting to about 10% (by mass dry material) of the amyloid fibril material. A yellow substance in this fraction shows absorbance maxima (270, 280 and 430 nm) similar to those observed for transthyretin in normal serum. Gas chromatography/mass spectrometry of the methanol extract revealed the presence of saturated fatty acids (C14:0, C16:0 and C18:0 in the corresponding ratio 2:8:5) and polyunsaturated fatty acids (C16:1, C18:1, C18:2 and C20:4 in the corresponding ratio of 1:2:1:1) as further constituents of the amyloid fibril material.

Mental health status in systemic lupus erythematosus

Mental health status was assessed in 43 SLE patients and 32 healthy controls applying the GHQ-30 version of The General Health Questionnaire. A 46.5% prevalence of non-psychotic psychiatric disturbance was found in SLE patients compared to 15.6% in the control group (p = 0.01). Factor analysis displayed that SLE patients reported far more depression and difficulty in coping compared to controls. In SLE patients, impaired mental health showed significant associations to several disease associated neurological manifestations, as well as to disease activity. The results indicate that the disease itself influences the psychological well being in a substantial number of patients with SLE.

Bovine glomerular amyloidosis: morphological studies

Bovine kidney material with advanced glomerular deposits of amyloid was studied immunohistochemically using the avidin biotin complex immunoperoxidase method, with rabbit anti-horse AA serum as primary antibody. Severely affected glomeruli consisted of strongly reacting positive material, obscuring all cellular structures. Transmission electron microscopy revealed that the amyloidotic areas, with evident amyloid fibrils, also contained a considerable admixture of cellular remnants. In this investigation it was found that such material was more abundant in the bovine glomerular amyloid masses than in amyloid laden organs from other animal species, and it is discussed to what extent this observation may explain the varying tinctorial properties of amyloid deposits in bovine tissues, and the relative high content of histones in bovine amyloid proteins.

The effect of serum amyloid protein A fragment-SAA25-76 on blood platelet aggregation

The effect of the major acute phase protein serum amyloid A (SAA) on collagen induced platelet aggregation was investigated. A truncated version of SAA, SAA25-76 was tested for inhibitory capacity of collagen induced platelet aggregation in platelet-rich plasma (PRP) and whole blood (WB). The tetrapeptide RGDV, a known inhibitor of platelet aggregation, was included as a reference compound. SAA25-76 at a concentration of 390 micrograms/ml inhibited platelet aggregation induced by 1 microgram/ml of collagen in PRP. This corresponds to the plasma concentration of SAA during an acute phase response. However, the inhibitory effect of the SAA25-76 fragment was lost at higher collagen concentrations (> or = 2.0 micrograms/ml). The SAA fragment at 390 micrograms/ml had no significant effect on platelet aggregation in WB. In contrast, RGDV blocked collagen induced platelet aggregation in both PRP and WB.

Characterization of proteoglycans associated with mouse splenic AA amyloidosis

We here report for the first time on the chemical characteristics of proteoglycans associated with mouse splenic reactive AA amyloid. Amyloid was induced in CBA/J mice by two different procedures; conventional casein treatment and by employing Freund's complete adjuvant, accelerated by Trypan Blue. Pulse-labelling was employed at distinct stages during amyloid development, followed by [35S]proteoglycan characterization of organ extracts. Repetitive 35S injections were also administered during the phase where amyloid deposition occurred most rapidly. Proteoglycans were extracted with guanidine in the presence of protease inhibitors and purified. The results showed that the production of proteoglycans is dramatically enhanced during amyloidogenesis, the glycosaminoglycan and proteoglycan accumulation being not only dependent on alterations in proteoglycan catabolism, but rather on increased synthesis. The increment could be demonstrated even at the stage before microscopic detection of amyloid deposits, clearly suggesting that the upregulation of proteoglycan expression precedes amyloid fibril formation. Two major proteoglycans were found to accumulate in advanced splenic amyloid; one a heparan sulphate proteoglycan of approx. 200 kDa with a core protein of 70 kDa, the other a chondroitin sulphate proteoglycan of smaller size. Moreover, free dermatan sulphate chains seemed to specifically accumulate in the organs during amyloid fibrillogenesis. We suggest that free glycosaminoglycans may be a specific feature of amyloidosis and that different proteoglycans and glycosaminoglycans play a role in formation and stabilization of amyloid fibrils in vivo.

Autonomic function in systemic lupus erythematosus

A controlled study with paired analysis of data was performed in 34 patients with systemic lupus erythematosus (SLE) and 34 age and sex-matched healthy controls. Autonomic function was not affected significantly in SLE patients as judged by standardised cardiovascular tests. Pancreatic polypeptide (PP) response to meal stimulation, which is impaired in parasympathetic failure, was for unknown reasons found to be significantly increased in SLE patients both in unstimulated and stimulated states. Neither cardiovascular nor serological tests could thus reveal significant autonomic dysfunction in SLE. Drugs with cardiovascular effects highly influenced autonomic function and could thus be misinterpreted as autonomic dysfunction caused by SLE itself.

Tissue distribution of antigen(s) defined by monoclonal antibody D8/17 reacting with B lymphocytes of patients with rheumatic heart disease

Monoclonal antibody D8/17 originally prepared by immunization of mice with B cells from a patient with rheumatic heart disease (RHD) reacts with epitopes expressed on significantly elevated proportions of B cells (10-35%) from all patients with acute rheumatic fever or rheumatic heart disease. This B cell marker does not segregate with any known HLA or DR phenotype. We have examined the reactivity of D8/17 with a broad assortment of human tissues, using indirect immunofluorescence. Strong positive reactivity of D8/17 was observed with cardiac muscle, skeletal muscle, and smooth muscle of blood vessels. Positive fluorescent staining was also noted in cell membranes of hepatocytes and cells lining bile canaliculi as well as in epithelial cells of skin, esophagus, and cervix. D8/17 mAb binding to cardiac muscle was markedly diminished by preincubation of mAb with KH B cell line originally established from an RHD patient. D8/17 mAb binding to human heart was also inhibited by preincubation with myosin and tropomyosin but not by actin. Using the D8/17 mAb in immunoblots, positive binding was noted by the antibody to recombinant type M6 protein, vimentin, and myosin. Our findings indicate that the B cell antigen reacting with mAb D8/17 may be related to contractile proteins present in heart, skeletal and smooth muscle, and may also share epitopes with some components of group A streptococci.

The primary structure of serum amyloid A protein in the sheep: comparison with serum amyloid A in other species

Serum amyloid A (SAA) protein was isolated from acute phase sheep sera by ultracentrifugation, gel filtration and ion-exchange chromatography. The purified protein was characterized by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing, amino acid composition and Edman degradation. Protein SAA sheep consists of 112 amino acid residues and has a blocked N-terminus. The amino acid sequence showed a high degree of homology with SAA proteins from other species, especially at positions 32 to 54, indicating that this particular part of the protein is important for its function. When compared to human protein SAA, nine inserted amino acids could be demonstrated, located in regions 69 to 77. Similar observations have been seen in cow, horse, dog, cat, and mink protein SAA. Heterogeneities were found in positions 28, 55, 63, 64, 66, 75, 77, 78, 80 and 89. Positions 63, 64, 66, 75, 77, 78 and 80 revealed the existence of a minor gene product of protein SAA sheep. The minor variant of protein SAA sheep is identical in these positions with the corresponding positions in protein SAA cow. By comparing the amino acid sequences of the different SAA proteins, two separate branches in the evolutionary pattern of protein SAA appear. One of the branches includes the species with the insertion which represents also one of the more heterogeneous part of the protein.

Interaction between circulating amyloid fibril protein precursors and extracellular tissue matrix components in the pathogenesis of systemic amyloidosis

Amyloidosis is a heterogeneous group of diseases characterized by deposition of a fibrillar, proteinaceous material, amyloid, in various tissues and organs. Increasing knowledge about the different proteins that constitute the amyloid fibrils has made it possible to classify amyloidosis by the fibril protein, which appears more rational than the traditional classification by its clinical expression. A serum protein is the precursor of the amyloid fibril protein in the various systemic forms of amyloidosis. Although the chemical composition of amyloid is presently well known, the pathogenetic processes that convert such proteins into a fibrillar form and lay them down in the tissues are far from clarified. We suggest some pathogenetic mechanisms for amyloid deposition, involving different types of fibril protein, their precursors, the extra-fibrillar amyloid P component, glycosaminoglycans, proteoglycans, and calcium with special reference to experimental work from our research group.