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The aim of this work was to evaluate the diagnostic accuracy of three different analytical methods for the detection of antineuronal antibodies and outline how they might be used to diagnose Paraneoplastic Neurological Syndromes (PNS) in a more effectively and rationally way. One hundred and four patients with neurological diseases were studied: 38 with paraneoplastic neurological disorder, 44 with other neurological diseases, and 22 with systemic autoimmune diseases and neurological disorders. 20 healthy subjects and 18 subjects with tumour without neurological disorders were also studied. Antineuronal antibodies were tested using three methods: Western blot (WB); Line-blot (LB); and indirect immunofluorescence (IIF) on primate cerebellum. The diagnostic sensitivity of the IIF, WB and LB methods was 28.9%, 26.3% and 36.8%, respectively, and their specificity was 95.2%, 97.1% and 98.1% respectively. The combined use of the three methods brought the sensitivity to 39.4%. The results of this study show that the methods used in clinical laboratories for the detection of antineuronal antibodies have good specificity. Among the three methods assessed, LB showed the highest diagnostic accuracy and also allowed for recognition of fine antibody specificities. According to these results we can suggest that LB should be used as the method of choice to search for paraneoplastic antibodies.

Previous studies have demonstrated that serum anti-actin antibodies are a reliable marker of intestinal damage severity in coeliac disease.To validate in a multicentre study the clinical usefulness of serum IgA anti-actin antibody ELISA and its possible use in monitoring intestinal mucosa lesions during gluten-free diet.Four centres recruited 205 newly diagnosed coeliac disease patients with villous atrophy, 80 healthy controls and 81 "disease" controls. Twelve coeliac disease patients on gluten-free diet but with persistent symptoms underwent serum IgA anti-actin antibody assay and intestinal histology evaluation. IgA anti-actin antibody ELISA was performed with a commercial kit. All coeliac disease patients underwent intestinal histology study.IgA anti-actin antibodies showed a sensitivity of 80% and a specificity of 85% in the diagnosis of coeliac disease patients with villous atrophy. The area under the receiving operator curve for anti-actin antibodies was 0.873 [95% C.I. 0.805-0.899]. Serum anti-actin antibodies values were significantly higher in coeliac disease patients than in healthy or "disease" controls (P0.0001). Serum anti-actin antibodies were positive in 41 of the 60 coeliac disease patients with mild intestinal histology lesions (69%) and in 123 of the 145 with severe lesions (85.3%) (P0.05). There was a significant inverse correlation between anti-actin antibody values and the villi/crypts ratio (r=-0.423; P0.0001). In the 12 coeliac disease patients on gluten-free diet who underwent re-evaluation as they were persistently symptomatic, intestinal histology showed three cases with persistent villous atrophy: all of these were positive for serum anti-actin antibodies ELISA, whereas both serum anti-tTG and EmAs were negative. The other nine patients showed normal intestinal villi and were negative for serum anti-actin antibodies.Anti-actin antibodies are a reliable marker of severe intestinal mucosa damage in coeliac disease patients and a simple ELISA technique offers an accurate method for their determination. These antibodies seem to be a very reliable marker of persistent intestinal damage in coeliac disease patients.

Blast cell extracts from patients with acute non lymphoid leukemia (ANLL) express cancer procoagulant (CP). This factor X (FX) activator is distinct from tissue factor (TF) in that it does not require factor VII (FVII) to trigger blood coagulation, it acts as a cysteine proteinase and is not present in normal mononuclear cells. To assess whether there is any relationship between the presence of CP and the status of the disease, ANLL patients have been studied at diagnosis, during remission, at relapse. The procoagulant activity in either the presence or absence of F VII and sensitivity to cysteine proteinase inhibitors were tested on cell extracts. Immunoreactivity was explored with an anti-CP polyclonal antibody. Data obtained in 91 newly-diagnosed ANLL patients (subtypes M1 to M5, FAB classification) confirmed the presence of CP in M1 to M4 groups (mean +/- SE FVII-independent activity: M1 = 2.1 +/- 0.7 unit/mg; M2 = 5.7 +/- 1.7 unit/mg; M3 = 31.5 +/- 8 unit/mg; M4 = 1.6 +/- 1.2 unit/mg); CP was absent in the M5 type. In eight patients analyzed in a subsequent phase of partial remission, specific activity had dropped from 26.9 +/- 7.8 to 10.5 +/- 4.0 unit/mg. Activity was virtually absent (0-0.05 unit/mg) in the bone marrow of 37 patients studied at complete remission. Bone marrow samples from six subjects tested at different intervals after complete remission were repeatedly negative for CP but became positive 2 to 5 months before relapse. Upon relapse, the FVII independent activity rose to 24.2 +/- 8.2 unit/mg.(ABSTRACT TRUNCATED AT 250 WORDS)

In a previous study we characterized cancer procoagulant (CP), a 68 kd cysteine proteinase which directly activates coagulation factor X in various subtypes (from M1 to M5) of acute non-lymphoblastic leukemia (ANLL). The aim of this study was to determine whether CP is also expressed by acute lymphoblastic leukemia (ALL) cells. Blasts from 25 ALL patients were extracted and tested for their procoagulant properties. 16 samples (64%) shortened the recalcification time of normal human plasma, and 9 (36%) did not. 8 of the 16 active samples showed properties compatible with CP, i.e. independence from factor VII in triggering blood coagulation and sensitivity to cysteine proteinase inhibitors. Selected samples also cross-reacted with a polyclonal antibody raised against purified CP. The specific activity of CP in ALL extracts was significantly lower than in most ANLL types previously studied (all but M4). These finding indicate that CP can be a property of the lymphoid phenotype although its expression may be lower than in the myeloid phenotype.

To verify whether cancer procoagulant (CP), a cysteine proteinase procoagulant distinct from tissue factor (TF), is associated with leukemic cells, we assayed the procoagulant activity of blast cell extracts from 26 patients with different cytological subtypes of acute nonlymphoid leukemia (ANLL) according to the French-American-British classification. All the samples except two shortened the recalcification time of normal human plasma, the effect being significantly greater in the M3 subgroup. The two criteria used to distinguish between CP and TF, independence from factor VII in initiating blood coagulation and sensitivity to cysteine-proteinase inhibitors, were positive in 19 samples from M1, M2, M3, and M4 cytological subtypes. None of the M5 samples fulfilled these criteria. In addition, M1, M2, M3, and M4 samples immunoreacted with an anti-CP goat polyclonal antibody on an Ouchterlony immunodiffusion plate. This study provides the first evidence for a procoagulant other than TF that is associated with leukemic cells.