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Biomedical subjects

T Palosuo

Publications and source records attributed to T Palosuo.

At least 127 records · Page 7Linked to original sources
PubMed1988

Significance of rheumatoid factors in an eight-year longitudinal study on arthritis.

A community-based cohort comprising 150 patients with recent-onset seropositive arthritis or seronegative oligoarthritis or polyarthritis was monitored for 8 years. Of the different rheumatoid factor (RF) tests, the initial positivity in the most sensitive assays (latex slide test and IgM-RF by enzyme immunoassay) was the most reliable factor when distinguishing between the erosive and nonerosive cases. The individual RF isotypes fluctuated in four serial specimens, but each patient tended to preserve his or her reactivity pattern. Seroconversion from positive to negative within the 1st year of follow-up did not indicate a particularly good long-term prognosis.

Arthritis, Rheumatoid↗
PubMed1988

Effective inhibition of cardiolipin-binding antibodies in gram-negative infections by bacterial lipopolysaccharide.

Anticardiolipin antibodies (ACA) were detected by solid-phase enzyme immunoassay in the majority of sera from patients with Gram-positive and Gram-negative bacterial infections. The response involved all the major immunoglobulin classes IgG, IgM, and IgA. The specificity of the ACA was studied in competitive inhibition experiments with three putative antigens: cardiolipin, lipopolysaccharide (LPS) isolated from Salmonella minnesota, strain Re 595, and synthetic Escherichia coli lipid A. The binding of IgG class ACA from the sera of five patients with Gram-negative infections was effectively inhibited by LPS, whereas 100-fold more cardiolipin was required for comparable inhibition. Pure lipid A was a less effective inhibitor of anticardiolipin activity than LPS. This pattern of reactivity was not seen in sera from patients with Gram-positive infections, syphilis, or systemic lupus erythematosus. Our findings suggest that cardiolipin may not be the inducing antigen for the cardiolipin-binding antibodies that develop in Gram-negative infections.

Antibody Specificity↗
PubMed1988

Anticardiolipin response and its association with infections in young and middle-aged patients with cerebral infarction.

Antibodies binding to solid-phase cardiolipin (anticardiolipin antibodies, ACA), which are closely associated with lupus anticoagulant activity, have been found in patients with thrombosis. ACA are often seen also in patients after acute infections. To study further our recent observation on the association between infection and cerebral infarction in young and middle-aged patients we measured anticardiolipin response (IgG, IgM, IgA) in paired sera from 54 consecutive patients with cerebral infarction under 50 years of age and in 54 community controls matched for sex and age. An elevated IgG-class ACA level or a significant change in level as observed in 2 serial samples occurred in 15 (28%) patients, but in only 4 (7%) controls (P less than 0.02). These ACA levels were only slightly elevated, and there were no patients with levels approaching values commonly seen in lupus anticoagulant-positive patients. Neither were there any patients with systemic lupus erythematosus (SLE) as an underlying disease. The combination of IgG-class ACA positivity and preceding probable bacterial infection (based on clinical, cultural or serologic data) was found in 10 patients (18%) but in only 2 controls (4%) (P less than 0.05). There were no significant differences in IgM- or IgA-class ACA between the patients and their controls. These results suggest that IgG-class ACA response associated with preceding probable bacterial infection is more common in patients with cerebral infarction than in their community controls. However, slightly elevated ACA are probably only indirect indicators of preceding infection and not directly involved in the pathogenesis of thrombosis itself.

Adolescent↗
PubMed1988

Rheumatoid factor isotypes in patients with rheumatoid arthritis and in subjects with "false-positive" reactions.

The appearance of RFs, as detected by standard serological techniques, often precedes the onset of clinical RA by years. This pre-rheumatoid immunological reactivity is not associated with C-reactive protein response or occurrence of antibodies against native type II collagen. The profile of RF isotypes appeared to be similar between pre-rheumatoid and rheumatoid sera. RA sera contained somewhat more frequently IgG and IgA class RFs than "false-positive" sera from a community-based population sample. 7S IgM could be detected at about the same frequency in rheumatoid sera, in RF-positive pre-rheumatoid sera and in sera with "false-positive" RF reactions. The significance of the findings in terms of the pathogenesis of RA will be discussed.

Adult↗
PubMed1988

Significance of false positive syphilis reactions and anticardiolipin antibodies in a nationwide series of pregnant women.

The highly sensitive rapid plasma reagin (RPR) and Treponema pallidum hemagglutination tests were used to determine the frequency of false positive syphilis reactions in a nationwide series of pregnant women in Finland. The frequency found was 14/10,000. Two cases of systemic lupus and 2 of undefined connective tissue disease were found during a 20-month period among 134 false positive reactors in a series of 110,000 separate pregnancies. The risk of subsequent fetal loss among false positive syphilis reactors was 7%, similar to the risk in RPR negative controls. Half of the sera in the highest RPR titer groups and 1/3 in the lowest titer groups had elevated levels of anticardiolipin antibodies in solid-phase enzyme immunoassay. This assay did not increase the risk of clinical disease or subsequent fetal loss above the risk of RPR test alone.

Adult↗
PubMed1987

Raised acute-phase glycoprotein and IgM levels in cord serum.

The usefulness of a combined screening for acute-phase glycoproteins and IgM level in cord sera to denote various intrauterine or delivery-associated disorders was tested in approximately 2,000 consecutive cord sera. Increased glycoprotein level, measured by sensitive and technically simple concanavalin A binding nephelometry, showed a significant association with birth injuries and abnormalities of amniotic fluid, whereas raised IgM levels were linked to maternal genitourinary infections and to cesarean sections performed because of fetal distress. The correlation between these putative risk indices was poor (r = 0.38). Both indices were connected with severe neonatal disease and/or poor outcome of the child, but since such conditions were also otherwise evident at birth, routine screening by these tests was considered unwarranted.

Acute-Phase Proteins↗
PubMed1986

Anticardiolipin response in acute infections.

Paired serum specimens from 149 patients with six different infections verified by a significant rise in the specific antibody level were tested for anticardiolipin antibodies using enzyme-linked immunosorbent assay. Significantly raised levels, at least in one immunoglobulin class, were detected in 32% of the cases, and significant changes in the level indicating an ongoing process, in 26%. Taken as a whole, the response involved the immunoglobulins IgG, IgM, and IgA, although in patients with mumps the significantly raised levels were virtually confined to the IgA class. The binding of syphilitic antibodies to solid-phase cardiolipin was readily inhibited by cardiolipin liposomes, whereas this pattern of reactivity was noted in only one of four nonsyphilitic sera. It was concluded that anticardiolipin antibodies occur very frequently in a wide variety of uncomplicated infections.

Adult↗
PubMed1986

C-reactive protein in population samples.

The significance of C-reactive protein (CRP) was studied in three different sets of specimens. Raised levels (greater than 10 mg/l) were detected in 2.0% of 380 healthy blood donors from whom two blood specimens, taken at an interval of half a year, were tested. Except for two cases, only one of the two specimens was positive. Raised levels were found three times as frequently (in 6.6%) in a random middle-aged population sample consisting of 531 subjects. More than 40% of the raised levels could be connected to acute respiratory infections, and about 20% to smoking. Five of the 35 subjects (14%) in the population sample with elevated CRP had rheumatoid arthritis. The third set of sera comprised pre-illness specimens from 22 subjects who developed rheumatoid arthritis a few months to five years later. Although it had previously been proved that the majority of these sera contained rheumatoid factors, the CRP concentration was increased in one specimen only.

Acute Disease↗
PubMed1986

The distribution of class-specific rheumatoid factors is similar in rheumatoid and pre-illness sera.

The occurrence of IgM, IgG, and IgA class rheumatoid factors (RF) was compared by means of ELISA in 21 sera from patients with established rheumatoid arthritis (RA) and in 22 pre-illness sera from subjects who 4 months to 5 years later developed seropositive rheumatoid arthritis. The positive cases were virtually confined to three groups of about equal size: positive for all three RF classes, positive for IgM-RF and IgG-RF, and positive for IgM-RF only. Thus, the distribution of the RF isotypes was similar in rheumatoid and pre-rheumatoid sera.

Arthritis, Rheumatoid↗
PubMed1985

When does rheumatoid disease start?

Stored serum specimens collected in connection with a community-oriented epidemiologic study were available from 30 subjects who later developed seropositive rheumatoid arthritis. In 9 of these pre-rheumatoid specimens, the Rose-Waaler test result was positive, and in 16, the latex fixation test was positive. Two-thirds of the samples were positive when the interval between taking the blood specimen and onset of the disease was less than 4 years, and one-third were positive when the interval was greater than or equal to 4 years. The occurrence of rheumatoid factor preceded the onset of clinical disease more often in males than in females.

Adult↗
PubMed1985

Identical twins with the Rhnull phenotype of the regulator type in a Finnish Lapp family.

An inbred family A. G. with identical twin sisters having the Rhnull phenotype of the regulator type as confirmed by the maternal family data of Rh inheritance is reported. The family was traced back through church records for six generations. Several connections could be established with a Norwegian Sea Lapp community in which a family with the amorph Rhnull type has been reported. The closeness of the Finnish and the Norwegian Lapps was given special attention since, despite both of the communities are small and share a more or less common gene pool, they nevertheless seem to possess the two ultra rare Rh genes, Xor in the Finnish and r in the Norwegian family, producing, when homozygous, the Rhnull phenotype.

Adult↗
PubMed1985

Demonstration of antibodies to mosquito antigens in man by immunodiffusion and ELISA.

Cutaneous reactions to mosquito bites are believed to be immunologically mediated, but knowledge of the underlying mechanisms is very limited. In the present work, comprising 598 subjects, we show that precipitating and ELISA-reactive IgG-class antibodies occur frequently in the adult population. The operating antigen(s) were found in whole-body extracts of Aedes mosquitoes and also in a continuous mosquito cell line culture. The appearance of antimosquito antibodies seems to be correlated with the exposure to mosquito bites; however, massive exposure at an early age may result in a suppressed response.

Aedes↗
PubMed1985

Development of thyroid autoimmunity.

Two blood samples were taken at an interval of 5 years in a continuing epidemiological study of a rural population in south-western Finland with an age range of 40-64 years at commencement. Paired sera of 680 subjects were tested for antibodies against thyroglobulin and thyroid microsomal antigen. In the seroconversion cases the titres in the second specimens were either low or medium but never high. In the cases selected on the basis of the highest titres in the follow-up specimens, the titres in the baseline specimens were either high or medium but never low. These findings suggest that the emergence and the development of thyroid autoimmune seroreactions are slow processes.

Adult↗