A clinical study of serum antinuclear factor

Autoantibodies to extractable nuclear antigens (ENAs) pattern in rheumatoid arthritis patients: Relevance and clinical implications

OBJECTIVES

To study the frequency of different autoantibodies to extractable nuclear antigens (ENAs) in rheumatoid arthritis (RA) patients and to correlate findings with clinical manifestations, disease activity and radiological damage.

METHODS

A total of 230 RA patients were included and 75 healthy controls. In all patients rheumatological assessment was done and routine laboratory investigations and immune profile were performed in both patients and controls, including: RF, ACPA, ANA and anti-ENAs (Ro/SSA, La/SSB, U1-RNP, anti-Jo-1 and anti-Sm). Radiological damage was scored using Sharp/van der Heijde, and disease activity was evaluated by DAS28-ESR and DAS28-CRP.

RESULTS

RF was positive in 101 (43.9%), ACPA in 220 (95.7%), ANA in 58 (25.2%), anti Ro in 31 (13.5%), anti-La in 10 (4.3%), anti-Jo1 in 5 (2.2%) and anti-RNP in 2 (0.9%). Anti-Ro/SSA positively correlated with sicca symptoms (p=.02), RF titer (p<.001), ANA (p<.001), DAS28-ESR (p=.026), and DAS28-CRP (p=.003). Anti-La antibodies correlated positively with SJC (p=.001), TJC (p=.001), ANA (p<.001), DAS-28 ESR (p=.007). Anti-Jo-1 correlated positively with interstitial lung disease (ILD) (p≤.001), RF titer (p=.037) and ANA (p≤.001). Anti-RNP antibodies correlated positively with disease duration (p≤.001), ACPA titer (p≤.001) and ANA (p=.014). In the controls ANA was positive in two (2.7%), anti-Ro in three (4%), and none of the controls tested positive for other autoantibodies.

CONCLUSIONS

In RA patients, positive ANA is frequent and positively associated with anti-Ro, anti-La and anti-Jo1 autoantibodies. Screening for autoantibodies against other anti-ENAs seems mandatory in RA patients especially when ANA is positive. RA cases with positive Anti-Jo-1 may develop anti synthetase syndrome and ILD.

A latex particle precipitation test in the diagnosis of thyroid disease

The method of latex particle precipitation has been applied to the detection of circulating antibody to a crude extract of thyroid. The sensitivity of the method is intermediate between that of the agar diffusion and the tanned cell haemagglutination techniques. If only the grosser degrees of latex precipitation are taken as being significant, the method would appear to be of equal value as the agar diffusion test in the diagnosis of lymphadenoid goitre.

The clinical associations of antinuclear antibodies in juvenile rheumatoid arthritis

To clarify further the clinical correlates of antinuclear antibodies (ANA) in children with juvenile rheumatoid arthritis (JRA) this study compared the features of 60 ANA positive and 25 ANA negative children with JRA. ANA was more likely to be present in those with pauciarticular JRA than polyarticular JRA particularly if the ANA was of high titer. ANA positive subjects were more likely to have extraarticular manifestations, especially iridocyclitis. No significant differences were observed in onset ages, sex distribution, season of disease onset, family histories, or prognosis. There was no correlation between ANA titer and disease activity. Thus, while certain clinical features do correlate with ANA positivity in JRA, most clinical manifestations do not occur with distinctively different frequencies in the ANA negative and ANA positive groups.

The musculoskeletal manifestations of cystic fibrosis

Twenty-seven patients with CF and joint complaints were reviewed. Twelve patients had arthritis, 11 had HPO, and four had symptoms of mechanical neck and back pain. We have confirmed the association of CF with an episodic form of arthritis. For the first time, we have reported that a subgroup of these patients later develop persistent synovitis with progressive asymmetric, erosive disease. The etiology of CF arthritis is unclear, but may relate to chronic infection and immune complex mechanisms. CF arthritis can be contrasted with CF induced HPO, which is associated with worse lung disease, a male predominance, and an older mean age of onset of symptoms. Mechanical neck and back pain may relate to an associated scoliosis or kyphosis in CF.

Polyclonal B-cell activation and increased lymphocyte helper-suppressor ratios in discoid lupus erythematosus

We studied polyclonal B-cell activation in twenty-six patients with discoid lupus erythematosus (DLE). Spontaneous plaque-forming cells of the IgA class (IgA-SPFC) as determined by a reverse haemolytic plaque assay were significantly more common in patients with DLE than in fifty control subjects. The patients showed a positive correlation between IgA-SPFC and OKT4/8 ratios and also had a significantly higher mean OKT4/8 ratio. The two groups did not differ with regard to cells producing IgG or IgM or cells with OKT3, OKT4, OKT8 or OKMI markers. None of the three patients with DLE who had IgA-SPFC values which were above the mean (+2 s.d.) for the control subjects had positive tests for ANA or low serum C3 or C4, but two of the three also had increased IgG-SPFC values. The results indicate that polyclonal B-cell activation occurs in a small proportion of patients with DLE.

The significance of IgM antinuclear antinuclear antibody in rheumatoid arthritis and other connective tissue diseases

An investigation of the incidence of IgG and IgM antinuclear antibodies (ANA) in patients with connective tissue diseases showed that IgM ANA predominated in rheumatoid arthritis, whilst in systemic lupus erythematosus IgG antibodies were more common. Patients with other connective tissue diseases less frequently had antinuclear antibodies and there was little difference in the incidence of IgG and IgM antibodies. Cross reacting rheumatoid factors contributed to the IgM antinuclear activity of rheumatoid sera. IgM ANA was not related to disease activity in patients with rheumatoid arthritis. Immunoglobulin class differences of ANA in rheumatoid arthritis and systemic lupus erythematosus may reflect the differing pathological processes of these two diseases and may be of value in their differential diagnosis.

The precipitating antibody to an acidic nuclear protein antigen, the Jo-1, in connective tissue diseases. A marker for a subset of polymyositis with interstitial pulmonary fibrosis

The clinical significance of antibodies to the Jo-1 antigen in connective tissue diseases was studied. Clinical diagnoses of 11 patients who had anti-Jo-1 antibody were: polymyositis 8, dermatomyositis 1, and overlap syndrome 2 (polymyositis--systemic lupus erythematosus 1, polymyositis--scleroderma 1). All the patients who had anti-Jo-1 antibody showed interstitial pulmonary fibrosis, and in 2 patients anti-Jo-1 antibodies were detected before the appearance of lung disease.

Antinuclear antibody determinations in Ro(SSA)-positive, antinuclear antibody--negative lupus and Sjögren's syndrome patients

Antinuclear antibody determinations were performed on the sera of twenty-eight Ro(SSA)-positive patients, who failed to demonstrate significant antinuclear antibody titers on mouse liver, with the use of various heterologous and homologous substrates. These studies demonstrated the following: (1) The existence of substrate specificity among various tissues and cells employed in the detection of antinuclear antibodies in Ro(SSA)-positive patients. (2) The existence of a significant group of Ro(SSA)-positive lupus patients with prominent cutaneous findings and systemic disease who, despite the employment of a variety of antinuclear substrates, failed to demonstrate significant antinuclear antibody titer.

Juvenile psoriatic arthritis--an analysis of 60 cases

Sixty children who were considered to have juvenile psoriatic arthritis were analyzed retrospectively; the mean length of follow-up was 10.8 years. There was a female predominance of 3:2. The mean age at onset for both the psoriasis and the arthritis was between 8 and 9 years. A family history of psoriasis was present in almost half, and was a valuable clue in diagnosing the 26 of 60 who presented with arthritis first. The majority had a monarticular presentation, usually of the knee. Additional joints usually became involved sporadically in an asymmetric pattern, in both upper and lower limbs, so that 87% ultimately had polyarticular disease. This course is unlike the usual one of childhood arthritis. Although 40% were asymptomatic at follow-up, six patients required bilateral hip replacement, four within the first five years following the onset of arthritis. Sixteen patients received slow-acting drugs, usually gold; eight of these had had a polyarticular onset and seven a positive test for ANA.

A controlled study of ANA+ RF- arthritis

Thirty (7.5%) of 401 adult rheumatoid arthritis (RA) patients were antinuclear antibody positive (ANA+) and rheumatoid factor negative (RF-), and 15 of 16 patients who were followed for a year or longer remained so. Clinical, other laboratory, and radiographic parameters were compared among this group and 90 matched RA controls divided into ANA+RF+, ANA-RF+, and ANA-RF- groups. All groups were identical, except the ANA-RF- group, which had significantly fewer nodules and less destructive disease than the other three.

Rheumatoid arthritis--a sequel to HBsAg hepatitis

Reported here is the first case of classic rheumatoid arthritis emerging in the setting of hepatitis B surface antigen (HBsAG)-positive viral hepatitis. Polyfocal arthritis and myalgia, lymphadenopathy and constitutional symptoms were the presenting manifestations of anicteric hepatitis in this 23 year old man. Smooth muscles antibodies, HBsAg and "rheumatoid" factor were demonstrated initially. The hepatocellular disease, biopsy-proved, resolved completely and without recurrence; clinically and serologically. Latex test positivity persisted, increasing in titer, and polyarthritis progressed to fulfull criteria for classic rheumatoid arthritis, with erosions on roentgenogram and characteristic synovial disease. After 60 months of follow-up, the rheumatoid synovitis has continued to progress despite appropriate therapy. The arthritis of viral hepatitis and the significance of rheumatoid factor in association with hepatocellular disease are discussed.

Studies on a new acute phase protein. I. Immunocytochemical demonstration of the origin

Synovial fluid of patients with rheumatoid arthritis or traumatic arthritis contains an antigen which is thermostable to boiling temperature and insoluble in ethanol. The antigen was not found in sera of healthy subjects but it is present in numerous sera of patients with different inflammatory diseases. The partial purification of the antigen and the production of specific antisera are described. Immunofluorescent staining of tissue sections and blood smears indicates, that the antigen is a cytoplasmic protein of polymorphonuclear leucocytes. Monocytes contain the antigen to a lower degree, it was not found in eosinophils and lymphocytes. In addition, the influence of different fixing agents and of other pretreatment on the pattern of the cell fluorescence was studied. We propose to designate the antigen as thermostable granulocyte antigen (TSGA).

Substrate specificity of antinuclear antibodies in scleroderma

Studies of antinuclear antibodies (ANA) were carried out in 39 cases of systemic scleroderma and for comparison in 19 cases of systemic lupus erythematosus (SLE) and 4 of mixed connective tissue disease (MCTD) using indirect immunofluorescence (IF) methods under standard conditions. The results on three different substrates--monkey esophagus, guineapig lip and rat liver--are reported. In 48.7% of scleroderma cases ANA showed a substrate specificity. The highest percentage of positive results in scleroderma was obtained on monkey esophagus (97.4%) and the lowest on rat liver (61.5%). In SLE and MCTD, in contrast, only about 13% of the sera displayed such specificity. If only sera with substrate specificity are considered, the positive results on monkey esophagus and rat liver are 94.7% and 21.1%, respectively. Titers of sera reacting positively on 2 or 3 substrates were mostly in agreement, although some sera both in systemic scleroderma and SLE showed higher titers on monkey esophagus. The IF pattern was usually the same regardless of the substrate, Tests for ANA in scleroderma should be performed on at least 2 substrates simultaneously.

Antinuclear antibody with distinct specificity for polymyositis

In the course of studying antinuclear antibodies in the rheumatic diseases, a new precipitin reaction (provisionally referred to as PM-1) was observed between calf thymus nuclear extract and polymyositis sera. Objectives of this study were to further define the immunologic nature of this reaction and to determine its specificity for polymyositis. Immunodiffusion studies using calf thymus nuclear extract revealed the PM-1 precipitin line in 17 of 28 patients with polymyositis. This reaction was not produced by sera of 460 patients with other diseases. Enzyme and heat treatments of the nuclear extract showed that PM-1 was distinct from native DNA, ribonucleoprotein, and Sm antigens. Fractionation of PM-1-positive serum by 30% ammonium sulphate and Sephadex G-200 chromatography revealed that the factor producing the PM-1 precipitin reaction was in a serum fraction which showed only IgG by immunoelectrphoresis against anti-whole human serum. Because of the apparent strong specificity, the PM-1 system may represent a marker antibody for polymyositis.

Antinuclear antibodies (ANA): immunologic and clinical significance

The methods currently used for the detection of ANA have been analyzed, with emphasis on their practical application to the diagnosis of the CTD. The use of the indirect IF-ANA test was recommended as a screening procedure to detect ANA. The need to standardize the technique using a single substrate and fluorescent conjugates with uniform F/P ratios was stressed. Most importantly, the value of titrating ANA for the diagnosis of the CTD was discussed. ANA titers higher than 1/500 are usually very significant clinically, often found in spontaneous or drug-induced SLE and few other CTD. The immunologic aspects of ANA and their potential value as aids in the diagnosis and management of the CTD were discussed. Anti-nDNA antibodies have been found to have a high degree of specificity for SLE and high titers of these antibodies correlate well with low levels of serum complement and severity of kidney involvement. The spectrum of ANA in the sera from patients with SLE has been expanded with the finding of anti-Sm antibodies which, when detected by gel precipitation with prototype serum, have been found so far only in SLE. Some of these antibodies have been found to have prognostic significance. Patients with MCTD and a group of patients with SLE have high titers of serum ANA with specificity for an RNase-sensitive component of ENA. The group of SLE patients defined by the presence of these antibodies (anti-Mo) have a better prognosis and in general develop only mild nephritis or have no kidney involvement at all. High titers of pure antinucleolar antibodies probably are found almost exclusively in the sera of patients with scleroderma. Some ANA have organ specificity, and GS-ANA have been found in all patients with Felty's syndrome and in a large proportion of patients with RA. One of the great advances in the field has been the recognition that ANA can be induced in the human and in experimental animals by the use of a number of therapeutic agents. Some of these agents can also induce a clinical picture resembling spontaneous SLE, though kidney involvement does not occur or is extremely mild. It is interesting that the whole spectrum of ANA can be found in drug-induced LE except anti-nDNA antibodies which have been associated to the pathogenesis of immune complex nephritis in spontaneous SLE. There is no doubt that research on ANA has contributed a great deal to the understanding of the CTD and will continue to be a valuable tool for the clinician and the investigator.

Granulocyte reactive antinuclear factors in juvenile rheumatoid arthritis

The prevalence of mouse liver reactive antinuclear factors (L-ANF) and human granulocyte reactive antinuclear factors (G-ANF) was determined in sera from 34 age- and sex-matched pairs of patients with juvenile rheumatoid arthritis (JRA) and controls. Neither type of antinuclear factor was found in any of the control sera, whereas of the patient sera, 35% were L-ANF positive and 59% were G-ANF positive. 90% of the G-ANF positive sera were of the IgG class and 50% were able to fix complement. L-ANF was most frequent in female patients. Several types of ANF were associated with the polyarticular form of the disease. Such varying prevalences of ANF with disease types might indicate that JRA is a syndrome rather than a disease. In particular, the complement fixing G-ANF titre was positively correlated with parameters related to disease activity. The great variation in prevalence figures of different ANF types previously reported and the possible clinical significance of these auto-antibodies are discussed.

Autoantibodies in childhood connective tissue diseases and in normal children

The prevalence of nine serum autoantibodies has been studied in 117 children with various connective tissue disorders and in 134 normal controls. In juvenile rheumatoid arthritis rheumatoid factor was present in 5%, and antinuclear factor in 4%, compared with an incidence of 4% and 0% respectively in controls. In Henoch-Schönlein purpura there was little evidence of associated autoimmune disorder. Gastric parietal cell and thyroid microsomal antibodies were found in 9% and 10% of our control population, but the significance of this is not clear. It is concluded that in children the presence or absence of autoantibodies as diagnostic criteria should be interpreted with the greatest caution.

Studies on nuclear staining by the fluorescent antibody method. I. Non-immunological factors leading to nuclear fluorescence

The causes of non-specific nuclear staining in the fluorescent antibody method were investigated. Minute amounts of labelled basic proteins, present in labelled sera, stain nuclei in both direct and indirect methods.

The attraction of these basic proteins is caused by electrostatical forces, binding basic items to the nuclei like basic dyes.