[Clinical significance of antiribosomal antibodies. Study Group on Autoimmunity (GEAI)]. / Signification clinique des anticorps antiribosomes. Groupe d'étude auto-immunité (GEAI).

PURPOSE: Autoantibodies directed against the ribosomal P proteins, P0, P1 and P2 (anti-P), have been related to lupus-related psychosis and/or depression. The diagnostic value of antibodies directed against other ribosomal proteins or 28S RNA (anti-no-P) remains unknown. A multicenter study including ten centers belonging to the study group for autoimmune diseases (GEAI) was conducted in order to determine the diagnostic value of anti-P and anti-no-P antibodies in a large population of patients. METHODS: The patients were selected on the basis of the presence of serum anti-ribosomal antibodies detected by indirect immunofluorescence (IF) on rat liver/kidney/stomach/pancreas sections and human HEp2 cells. The clinical course of all patients was studied using a predetermined survey. The specificity of anti-P antibodies were determined by Western blot. RESULTS: Anti-ribosomal antibodies were found in 82 patients. Fifty-five of them had systemic lupus erythematosus and 27 had another disease. Only 54% of the anti-ribosomal antibodies detected by IF were anti-P and were found in 69% of the patients with systemic lupus erythematosus. Anti-no-P antibodies (46%) were preferably detected in patients who suffered from another disease (78%). In patients with systemic lupus erythematosus, neurological and psychiatric disorders were more frequent in the no-P group (47% vs. 16%, P < 0.01) than arthritis, which was found more frequently in the P group (78% vs. 53%, P < 0.05). CONCLUSION: Anti P antibodies do not constitute a specific diagnostic marker of systemic lupus erythematosus, and lupus-related neuropsychiatric disorders would be preferably associated with the presence of anti no-P antibodies.

[Bacterial contamination of platelet concentrates by Propionibacterium acnes]. / Contamination bactérienne de concentrés de plaquettes à Propionibacterium acnes.

In this study, three incidents of platelet contamination by Proprionibacterium acnes and an investigation of the transfusion process have been reported, which occurred at the Nord-Pas-de-Calais Blood Center over a period of several months. P. acnes is a bacterium that is present in the cutaneous flora; it does not produce any toxin, and is rarely considered as a pathogenic agent; its occurrence is widespread, in particular in those regions that are rich in sebum (face, back, scalp), and it is extremely apparent during adolescence. The three incidents occurred following the transfusion of a pool of leucodepleted platelet concentrates obtained from immunodeficient patients. The clinical outcome was in all cases positive. It was considered that the bacterial contamination of platelet concentrates could reflect insufficient skin disinfection at the site of the venipuncture and a minimal bacterial risk involving the blood collection procedure.

Investigation of a large kindred with type IIB von Willebrand's disease, dominant inheritance and age-dependent thrombocytopenia.

Twenty-six members of four generations of one family in which a man was diagnosed in 1961 as having von Willebrand's disease (vWD) have been studied. Subtype IIB vWD and autosomal dominant inheritance was identified in 19 individuals with bleeding signs varying in severity and frequency. The absence of high molecular weight multimers of plasma von Willebrand factor (vWf) and the heightened interaction of plasma vWf with platelets in the presence of low ristocetin concentrations were consistent in all affected subjects. Nevertheless the degree of these abnormalities was variable without clearcut linkage to the severity of clinical symptoms. Thrombocytopenia was present only in the adult affected family members and the platelet count appeared to be age-dependent. The investigation of this family provides further evidence of the phenotypic variability in the vWf-platelet interactions within this vWD subtype.