Inhalation of organic solvents does not promote synovial tissue inflammation in rats

Organic solvent exposure is known to give rise to a variety of manifestations in the nervous system both in man and in animals. Cardiac and skeletal muscle can also be affected, and strange collagen-like diseases, arthritis and arthralgia have been reported. In this work PVG rats were exposed to inhalation of toluene, commercial hexane, an industrial steel primer, and a cold vulcanizer for 4 months. No signs of synovitis appeared, either macroscopically or histologically, and there were no systemic signs of inflammation as detected by increased acute phase reactants.

Joint manifestations in gastrointestinal diseases. 1. Pathophysiological aspects, ulcerative colitis and Crohn's disease

The many unique structural and functional features of the intestine may offer explanations to the well-established association between arthritis and inflammatory bowel diseases (IBD). In ulcerative colitis (UC) and Crohn's disease (CD) some 6-8% of cases develop peripheral joint disease which frequently correlates with the activity and extent of the underlying bowel disorder. Ankylosing spondylitis is also found rather frequently in UC and CD, but is apparently not related to the severity of colitis. The occurrence of rheumatic manifestations in these two IBD is reviewed in detail.

Amino acid sequence analyses of non-AA proteins from amyloid fibrils of bovine kidney

The elution pattern obtained when amyloid fibrils from amyloid-laden bovine kidneys were subjected to gel filtration under dissociating conditions revealed a larger amount of non-AA material (eluting between the void volume and protein AA) than usually seen in other species. SDS-PAGE of this non-AA fraction yielded several Coomassie blue stained bands. The most distinctive ones gave estimated molecular masses of 15 kDa, 18 kDa, 33 kDa and 43 kDa. These molecular species were electroblotted onto PVDF membranes, and were further characterized by amino acid composition analyses, cyanogen bromide cleavage and N-terminal analyses. The results revealed that the intermediate 'non-AA' fraction consisted of histones H2B, H3 and H4 in addition to protein AA also found in this fraction.

Joint manifestations in gastrointestinal diseases. 2. Whipple's disease, enteric infections, intestinal bypass operations, gluten-sensitive enteropathy, pseudomembranous colitis and collagenous colitis

This review addresses the clinical picture of rheumatic diseases seen in Whipple's disease, gluten-sensitive enteropathy, pseudomembranous colitis, collagenous colitis and that developing after enteric infections and intestinal bypass operations for morbid obesity. These disorders exemplify the interplay between antigen entrance through the gastrointestinal canal, specific bacterial properties and genetic host factors such as HLA B27. In most cases such as interplay results in formation of circulating immune complexes causing the development of peripheral joint disease.

Rabbit serum amyloid protein A: expression and primary structure deduced from cDNA sequences

Serum amyloid A protein (SAA), the precursor of amyloid protein A (AA) in deposits of secondary amyloidosis, is an acute phase plasma apolipoprotein produced by hepatocytes. The primary structure of SAA demonstrates high interspecies homology. Several isoforms exist in individual species, probably with different amyloidogenic potential. The nucleotide sequences of two different rabbit serum amyloid A cDNA clones have been analysed, one (corresponding to SAA1) 569 base pairs (bp) long and the other (corresponding to SAA2) 513 bp long. Their deduced amino acid sequences differ at five amino acid positions, four of which are located in the NH2-terminal region of the protein. The deduced amino acid sequence of SAA2 corresponds to rabbit protein AA previously described except for one amino acid in position 22. Eighteen hours after turpentine stimulation, rabbit SAA mRNA is abundant in liver, while lower levels are present in spleen. None of the other extrahepatic organs studied showed any SAA mRNA expression. A third mRNA species (1.9 kb) hybridizing with a single-stranded RNA probe transcribed from the rabbit SAA cDNA, was identified. SAA1 and SAA2 mRNA were found in approximately equal amounts in turpentine-stimulated rabbit liver, but seem to be coordinately decreased after repeated inflammatory stimulation.

Macromolecular properties of glycosaminoglycans in primary AL amyloid fibril extracts of lymphoid tissue origin

We have previously demonstrated the presence of glycosaminoglycans (GAGs) in water extracts of secondary AA amyloid fibrils. In the present study we isolated significant quantities of GAGs from fibril extracts of immunoglobulin light chain (AL) type derived from the spleens from two patients afflicted with primary amyloidosis. Employing ion-exchange chromatography and gel filtration subsequent to various specific chemical and enzymatic treatments, different types of high molecular weight GAGs were found in both preparations, but not in the corresponding normal splenic extracts. The amyloid-associated GAGs of the extracts derived from one patient consisted of 60% dermatan sulphate and 40% heparan sulphate whereas those obtained from the second spleen were 25% dermatan sulphate and 75% heparan sulphate. The heparan sulphate fraction occurred in the form of proteoglycans, whereas the dermatan sulphate apparently occurred as free GAG chains, resembling the data recently obtained from AA amyloid fibril extracts.

Naproxen free plasma concentrations and unbound fractions in patients with osteoarthritis: relation to age, sex, efficacy, and adverse events

Plasma samples from 237 patients with osteoarthritis treated with 750 mg naproxen daily were obtained after four weeks of active therapy. The samples were subjected to equilibrium dialysis, analyzed by high-performance liquid chromatography, and free concentrations and unbound fractions were determined. Within the free plasma concentration range in this large patient group, we could detect no association between free naproxen concentration and efficacy score or between free concentrations and adverse events. Free concentrations were 0.295 +/- 0.260 microgram/ml (mean +/- SD) and unbound fractions were 0.33 +/- 0.24%. Females had 65% higher free concentration compared to males (p less than 0.001). For females, but not for males, there was a statistically significant correlation (p less than 0.005) between age and free concentration. The free concentration was estimated to be 88% higher in an 80-year-old female compared to a 50-year-old. Females had a 41% higher unbound fraction than males (p less than 0.005). For females, but not for males, a statistically significant relationship between age and unbound fraction was found. The unbound fraction was estimated to be 62% higher in an 80-year-old female than in a 50-year-old.

Muscular weakness in systemic lupus erythematosus

We systematically evaluated muscular weakness in a series of patients with systemic lupus erythematosus (SLE) using standardized neurological scoring systems, namely Neuropathy Symptom Score for symptoms, and Neurological Disability Score for signs. Symptoms of weakness were statistically associated with clinical and electrophysiological evidence of nerve and muscle disease. Signs of weakness were statistically associated with malaise, disease activity, anemia, age, and raised erythrocyte sedimentation rate. Various disease associated variables influenced symptoms and signs differently. It is important to define a baseline characterizing muscular weakness in SLE before conclusions are drawn regarding its significance and prevalence.

High molecular weight glycosaminoglycans in AA type amyloid fibril extracts from human liver

Glycosaminoglycans have previously been identified in extracts of AA type hepatic amyloid fibril from a patient with amyloidosis associated with juvenile rheumatoid arthritis. The macromolecular properties of these polysaccharides are described here in more detail. By gel filtration and ion exchange chromatography glycosaminoglycans in the form of high molecular weight free chains were shown to coisolate with water extracted amyloid fibrils. About 60% of these were characterised as galactosamines (chondroitin sulphate/dermatan sulphate), whereas the remaining 40% consisted of N-sulphated glucosamines (heparin/heparan sulphate). The amyloid associated glycosaminoglycans were not part of intact proteoglycans in the fibril extracts.

Glycosaminoglycans in extracts of cardiac amyloid fibrils from familial amyloid cardiomyopathy of Danish origin related to variant transthyretin Met 111

We have previously demonstrated an association between secondary AA type amyloid fibrils and glycosaminoglycans (GAGs) in human liver. The present study was aimed at investigating whether a similar association could be demonstrated in isolated cardiac amyloid fibrils from a unique Danish family with amyloid cardiomyopathy related to variant transthyretin (TTR) with a single amino acid substitution of a methionin for leucine at position 111 (TTR Met 111). Using gel filtration and ion exchange chromatography, significant amounts of GAGs were detected in close association with purified myocardial amyloid fibrils, whereas only trace amounts of polysaccharides were present in the corresponding normal preparation. The GAGs were identified as 50% chondroitin sulfate, 33% heparin/heparan sulfate, and 17% hyaluronan. With the methods used the amyloid associated GAGs appeared as high molecular weight free polysaccharide chains, and not as part of intact proteoglycans (PGs) in the fibril extracts. We conclude that the association between purified amyloid fibrils and GAGs may be a general feature of amyloid deposits. Also, we suggest that the proportion of different GAGs in the amyloid deposits may depend both on the organ or tissues affected and the type of proteins making up the fibrils.

Peripheral neuropathy in systemic lupus erythematosus

We studied 33 consecutive patients with systemic lupus erythematosus (SLE) for neuropathy by employing the Neuropathy Symptom Score (NSS), Neurological Disability Score (NDS), EMG and nerve conduction velocity (NCV) studies, and determinations of vibration thresholds (VT). Polyneuropathy defined as NCV abnormalities of two or more nerves occurred in seven patients (21%). Neuropathic symptoms showed a poor correlation with NCV and VT, while clinical neuropathic signs, VT, and NCV correlated with each other in most instances. When reporting frequencies of neuropathy in SLE, NCV studies should be used as a basis. NSS, NDS, and VT give additional quantifiable information and can be useful in the follow-up of patients and for evaluating the response to therapy.

Identification of glycosaminoglycans in human renal and splenic secondary AA amyloid fibril preparations

The evidence that glycosaminoglycans (GAGs) are specifically associated with amyloid, is strong. In the present study we looked for GAGs in water extracts of amyloid fibrils from kidney and spleen laden with AA amyloid secondary to ankylosing spondylitis. Significant amounts of high molecular weight GAGs were isolated from the fibril preparations of both organs using ion-exchange chromatography and gel filtration procedures. The polysaccharides present in purified human renal and splenic amyloid fibril material were characterized as follows: a) Sulphated GAGs of high molecular weight were found in both renal and splenic amyloid fibril extracts, but not in extracts from corresponding normal tissues. b) All of the renal amyloid-associated high molecular weight GAGs were chondroitin sulphate/dermatan sulphate, whereas splenic amyloid-associated high molecular weight GAGs had a chondroitin sulphate/dermatan sulphate:heparan sulphate ratio of approximately 2:1. c) The findings gave no evidence that GAGs coisolated with AA amyloid fibrils were parts of intact proteoglycan molecules with several GAG chains.

Antibodies to the peptide from the plasmid-coded Yersinia outer membrane protein (YOP1) in patients with ankylosing spondylitis

Seventy-five Norwegian patients with ankylosing spondylitis (AS) were studied for class-specific antibody response against synthetic peptide, P81, representing the sequence of plasmid-coded outer membrane protein of Yersinia (YOP1) containing four amino acid homology (TDRE) with HLA-B27 sequence. Ten (16.7%), five (8.3%) and seven (11.2%) of 60 male AS patients showed elevated anti-YOP1 P81 antibody of IgA, IgG, and IgM class, respectively, whereas for each isotype only one (4%) of 25 healthy male controls was positive. Differences were not observed between female patients and controls. In all isotypes, antibody-positive patients were more frequently found in patients with active disease. The anti-YOP1 P81 antibody levels of the patients were generally not correlated with the antibody levels against the peptide representing the hypervariable region of HLA-B27 (B27 peptide). However, in one patient the antibody was shown to react with both peptides by cross-inhibition analysis. Overall, it appears that any causal relationship between YOP1 and pathogenesis of AS is not strong. Immunogenicity and cross-reactivity of the YOP1 region encompassing the TDRE sequence particularly at the T cell level require further study.

Autoantibodies to the HLA-B27 sequence cross-react with the hypothetical peptide from the arthritis-associated Shigella plasmid

We previously reported elevated serum antibody levels to a peptide representing the HLA-B27 polymorphic region (B27 peptide) in HLA-B27(+) ankylosing spondylitis (AS) patients. A plasmid (pHS-2) isolated from arthritogenic Shigella flexneri strains had been shown to encode an amino acid sequence homologous to HLA-B27. Rabbit antibody to this sequence (pHS-2 peptide) strongly cross-reacted with B27 peptide and, to a much lesser extent, with Klebsiella nitrogenase peptide. Serum antibody levels to pHS-2 peptide were studied in 160 spondylarthropathy patients. 12 of 115 (10.4%) AS patients, 2 of 45 (4.4%) patients with Reiter's syndrome or reactive arthritis as well as 6 of 147 (4.1%) normal controls were shown to have elevated anti-pHS-2 peptide antibodies. Antibody levels to B27 and pHS-2 peptides were significantly correlated in 134 HLA-B27(+) patients (r = 0.333, P less than 0.001). 13 of 15 affinity-purified anti-B27 peptide antibodies from patients strongly cross-reacted with pHS-2 peptide, whereas only 3 weakly cross-reacted to nitrogenase peptide. Leucine appeared to be a critical residue for this cross-reaction. AS patients' anti-B27 peptide antibodies reacted with HLA-B27 transfected L cells. These results may suggest that pHS-2 peptide more efficiently "mimics" B27 peptide than does nitrogenase peptide. Involvement of pHS-2 in pathogenesis of spondylarthropathy through molecular mimicry mechanisms requires further study.

[Neuromuscular symptoms and findings in systemic lupus erythematosus]

Systemic lupus erythematosus (SLE) gives rise to a variety of autoimmune and clinical phenomena in a multisystem manner. Both the central and peripheral nervous systems are involved as well as skeletal muscle. Based on our work with SLE patients, we describe the different categories of peripheral neuropathy and myopathy. We suggest that the disease be considered as a possible diagnosis, especially when evaluating women with symptoms and signs of neuromuscular abnormalities.

[Central nervous symptoms and findings in patients with systemic lupus erythematosus]

Systemic lupus erythematosus is a disease characterized by multiple autoimmune phenomena, and a broad clinical spectrum. Involvement of the central nervous system is common, and in the majority of patients occurs mainly as an organic brain syndrome or as migraineous headache. Cerebral atrophy as judged by CT scan is common. Cerebral infarction occurs in a minority of patients, mainly those with high disease activity and a high titer of anti-phospholipid antibodies. Systemic lupus erythematosus should be considered as a possible diagnosis in patients with certain central nervous system aberrations, especially young females.

Mink serum amyloid A protein. Expression and primary structure based on cDNA sequences

The nucleotide sequences of two mink serum amyloid A (SAA) cDNA clones have been analyzed, one (SAA1) 776 base pairs long and the other (SAA2) 552 base pairs long. Significant differences were discovered when derived amino acid sequences were compared with data for apoSAA isolated from high density lipoprotein. Previous studies of mink protein SAA and amyloid protein A (AA) suggest that only one SAA isotype is amyloidogenic. The cDNA clone for SAA2 defines the "amyloid prone" isotype while SAA1 is found only in serum. Mink SAA1 has alanine in position 10, isoleucine in positions 24, 67, and 71, lysine in position 27, and proline in position 105. Residue 10 in mink SAA2 is valine while arginine and asparagine are at positions 24 and 27, respectively, all characteristics of protein AA isolated from mink amyloid fibrils. Mink SAA2 also has valine in position 67, phenylalanine in position 71, and amino acid 105 is serine. It remains unknown why these six amino acid substitutions render SAA2 more amyloidogenic than SAA1. Eighteen hours after lipopolysaccharide stimulation, mink SAA mRNA is abundant in liver with relatively minor accumulations in brain and lung. Genes encoding both SAA isotypes are expressed in all three organs while no SAA mRNA was detectable in amyloid prone organs, including spleen and intestine, indicating that deposition of AA from locally synthesized SAA is unlikely. A third mRNA species (2.2 kilobases) was identified and hybridizes with cDNA probes for mink SAA1 and SAA2. In addition to a major primary translation product (molecular mass 14,400 Da) an additional product with molecular mass 28,000 Da was immunoprecipitable.

Electrophoretic study of proteins associated with pseudo-exfoliation syndrome

Lens capsule and aqueous humour from cataractous eyes with and without pseudo-exfoliation syndrome have been studied by SDS-PAGE electrophoresis. Four cataractous lenses with and four without pseudo-exfoliation were used. The pseudo-exfoliation positive capsule revealed two polypeptides not present in the control material, and accordingly, these components were regarded to be pseudo-exfoliation specific. The molecular weight of the respective polypeptides was estimated to be 14,400 and 16,300. No marked differences were found between the pseudo-exfoliation positive and negative aqueous humours.

[The antiphospholipid syndrome]

Coagulopathy leading to arterial and venous thrombosis is sometimes seen in patients with systemic lupus erythematosus (SLE). It is caused by antiphospholipid antibodies reacting with negatively charged phospholipid constituents of membranes and coagulation factors. The patients may also suffer from recurrent fetal loss and neurological manifestations, and may have intermittent thrombocytopenia and low serum concentration of complement factor C4. Patients without evidence of SLE or other immunological disorders may also exhibit this antiphospholipid antibody-associated thrombotic tendency. The patients are often young women, and it is important to be aware of this kind of coagulopathy, because it may take a most severe course in some of the persons affected.

The primary structure of equine serum amyloid A (SAA) protein

The complete amino acid sequence of equine serum amyloid A (SAA) was elucidated. The protein consists of 110 amino acid residues and contains an 8-amino acid residue insertion tentatively located between positions 69 and 70, as compared with human SAA. Microheterogeneities were detected at positions 16, 44, and 59, compatible with the existence of more than one SAA gene in the horse. This corresponds to the situation in man and mouse. Pronounced homology with SAA from man and several animal species was observed, thus confirming the conserved structure of this acute phase reactant and apoprotein of high-density lipoprotein (HDL).

Studies of humoral and cell-mediated immunity to peptides shared by HLA-27.1 and Klebsiella pneumoniae nitrogenase in ankylosing spondylitis

One-hundred and twenty-four patients with spondylarthropathies were studied for antibodies to the peptides from HLA-B27.1 and Klebsiella pneumoniae nitrogenase which share a QTDRED hexamer sequence. Of 60 male Norwegian ankylosing spondylitis (AS) patients 23.3% showed positive ELISA reactivity for B27.1 peptide compared with 4% of Norwegian male controls (P less than 0.10). This difference was not observed among patients and controls from New Mexico. All patients with anti-B27.1 antibody were HLA-B27+. Antibody to B27.1 peptide was present in 20% of normal female controls with at least one previous pregnancy. No female control without previous pregnancy showed positive anti-B27.1 peptide reactivity. Anti-Klebsiella peptide antibody was neither significantly elevated in AS nor correlated with anti-B27.1 peptide antibody. Significant migration inhibition by these peptides was not observed in AS or normal controls. The possible influence of epitope conformation, rather than sequence homology, in potentially cross-reacting determinants shared by bacterial antigens and human Class I molecules requires further study.

Ankylosing spondylitis and pregnancy

In contrast to what is known for RA, pregnancy does not improve the symptoms of AS. The majority of women with AS has unchanged or temporarily aggravated disease activity during pregnancy. AS associated with other inflammatory states like psoriasis, IBS, or peripheral small joint arthritis, may benefit from pregnancy. Women with AS can expect to have the same rate of fertility, course of pregnancy, and normal delivery as the healthy female population. In general, female AS patients have healthy babies. However, the chance for their offspring to develop AS later in life is slightly increased.