Particle-counting immunoassay (PACIA) of pregnancy-specific beta 1-glycoprotein, a possible marker of various malignancies and Crohn's ileitis.

Abstract

Pregnancy-specific beta 1-glycoprotein (SP1) was assayed by particle-counting immunoassay (PACIA) with a sensitivity of 1 microgram/L. In serum from 50 men, the SP1 concentration was less than 1 microgram/L, whereas three of the specimens from 46 nonpregnant women had values exceeding 1 microgram/L. In 29% of 950 consecutive patients' sera, SP1 concentrations exceeded 1 microgram/L--in sarcoma (six of six), in malignant hemopathies (101/127, 80%) such as myeloma (20/26, 92%) and acute myeloblastic leukemia (23/27, 90%), and in various other types of cancer (11/19, 58%) except for bronchial epithelioma, which did not lead to any significant increase of SP1 in the five patients examined. The concentration of SP1 was also frequently increased in patients with Crohn's ileitis (28/43, 65%) but not in patients with other inflammatory disorders.

Prognostic value of concentration of pregnancy‐specific β1‐glycoprotein (SP1) in serum of patients with breast cancer

“…The principle of this technique is the agglutination by SP1 of latex particles coated with anti-SP1 antibodies, the agglutination being measured by optical counting of the unagglutinated particles. When the commercial version of IMPACT@ was used, rather than a prototype as in the preceding work (Fagnart et al, 1985), sensitivity was increased from 1 pg/l to 0.3 pg/L At this level, the coefficient of variation calculated on 100 assays was 8 % . Samples with > 1 pg/l were assayed in duplicate.…”

“…Particle counting immunoassay of SPl SP1 was assayed by particle counting as described (Fagnart et al, 1985) using IMPACT@ instruments (Acade Diagnostic Systems, Brussels, Belgium). The principle of this technique is the agglutination by SP1 of latex particles coated with anti-SP1 antibodies, the agglutination being measured by optical counting of the unagglutinated particles.…”

“…SP1, a protein produced by the syncytiotrophoblast (Horne et al, 19766;Tatarinov et al, 1974) occurs in serum at a concentration of over pg/l, considered as the upper normal limit (Fagnart et al, 1985;Tatarinov and Solokov, 1977), not only in pregnancy but also in patients with trophoblastic tumors (Seppala et al, 1978) and various other malignancies (Wurz, 1979;Vicovac et al, 1982) including breast carcinoma (Horne et al, 19766;Fagnart et al, 1985;Searle et al, 1978), malignant hemopathies (Fagnart et al, 1985) and sarcoma (Fagnart et al, 1985). Recently SP1 values of > 1 pg/l were also found at a high frequency in Crohn's ileitis (Fagnart et at., 1985).…”

Development of a high sensitivity IgG-latex immunodetection system stabilized by hydration forces

“…6 This reaction can be measured either by light scattering, 7 turbidity change 8 or particle counting. 9 Hydrophobic latexes always tend to aggregate. This tendency is facilitated by an increase of the electrolyte concentration and by the adsorption of proteins on the particle surface.…”