No abstract

Myoblasts obtained from donors histoincompatible for several non-major histocompatibility complex antigens (i.e., including minor histocompatibility antigens) and from syngeneic donors were transplanted without any immunosuppression into the muscles of male dystrophic C57BL/10J mdx/mdx mice. Myoblasts from syngeneic mice resulted in the formation of a high percentage of dystrophin-positive fibers 16 weeks after the transplantation. There was no evidence of a cellular immune reaction against the donor myoblasts, i.e., no infiltration by CD4 or CD8 lymphocytes and no increased expression of granzyme B and interferon-gamma mRNAs. Transplantation of myoblasts obtained from donors histoincompatible only for non- major histocompatibility complex antigens produced a transient increase of dystrophin-positive fibers at 4 weeks after transplantation for some donor strains but not for others. For donor strains that did produce an increase at 4 weeks, the number of dystrophin-positive fibers was reduced 16 weeks after the transplantation. There was evidence of a cellular immune reaction-infiltration by CD4 and by CD8 lymphocytes and increased expression of granzyme B and interferon-gamma mRNAs. Transplantation of myoblasts obtained from male C57BL/10J +/+ mice into female C57BL/10J mdx/mdx mice also led to the presence of only a few dystrophin-positive fibers with the same signs of cellular immune reaction. In this later case, the cellular immune response was attributed to the H-Y minor antigens. Finally, antibodies against fetal calf serum were detected after both syngeneic and nonsyngeneic transplantations, indicating that the culture medium may also be a source of antigens. In mice, the presence of these antibodies against culture medium did not reduce the success of a first syngeneic transplantation.

Somatostatin treatment was administered to 20 psoriatic patients according to the following protocol: Continuous infusion (250 micrograms/h) for at least 2 days followed either by short infusions (1 h) at 8 A.M. and 8 P.M. (12 cases) or by repeating the initial 2-day infusion (eight patients). Before treatment (day 0) and on day 6, biopsy specimens were taken for routine examination (12 patients) and for ultrastructure (seven patients). In vitro immunological studies were carried out on peripheral blood lymphocytes (six patients) on day 0 and day 8. In two patients, somatostatin was stopped because of serious side effects. Thus, clinical results were evaluated in 18 patients, on day 30. In ten of them no improvement whatsoever occurred, two had a partial clearing and an almost complete remission was achieved in six others. Ultrastructural studies showed, on day 6, enlargement of the intercellular spaces with deposits of granular material of glucidic composition, associated with features of cellular damage. Percentages of T and B cells were unmodified but a significant depression of mitogenic stimulation by PHA and ConA was clearly observed on day 8. Even if somatostatin treatment may have a beneficial effect in some patients it seems much less valid than other well-known therapies for psoriasis.

The transportation of plasma specimens to specialized haemophilia centre laboratories for anti-factor VIII inhibitor titre determination is often necessary. The routine method of transporting frozen specimens on dry ice is limited by its cost and need for special handling. The present study was undertaken to evaluate the effect of storing specimens at room temperature on the FVIII inhibitor titre determinations using the Bethesda assay. Specimens stored both in liquid phase as well as adsorbed onto filter paper discs were studied. The results of the present study demonstrate that plasma specimens stored for up to 2 weeks at room temperature, either in liquid phase or adsorbed onto filter paper, yield equivalent measures of FVIII inhibitor titres using the Bethesda assay to plasma specimens stored frozen at -70 degrees C. Plasma specimens dried on filter paper discs and stored at room temperature offers a reliable, more practical and less expensive alternative to frozen plasma as a means of transport to specialized referral laboratories for analysis of anti-FVIII titres.

The use of porcine factor VIII (FVIII) (Hyate:C, Ipsen) has proven to be very successful in treating patients with FVIII inhibitors. The best way to predict the usefulness of porcine FVIII therapy, and/or to estimate the appropriate treatment dose in a given patient, is to measure the patient inhibitor titre against porcine FVIII with the Bethesda assay, using porcine FVIII as the source of FVIII in the assay. The goals of the present study were to (1) find the optimal storage temperature, diluent and concentration for a working solution of porcine FVIII to be used as the source of FVIII for the porcine Bethesda assay, (2) assess the reliability of the labelled FVIII units in the preparation of such working solutions of porcine FVIII and (3) compare the inhibitor titres determined by the Bethesda assay using both porcine and human standard reference curves for measuring residual FVIII. The results of the present study demonstrate that a ready-to-use working solution of 1 U mL(-1) of Hyate:C diluted in human FVIII deficient plasma, either containing or deficient in von Willebrand factor antigen, is stable for up to 12 months, at -20 degrees C. The preparation of the 1 U mL(-1) working solution could be reliably calculated based on the units indicated on the vial label. Finally, using the human standard curve yields similar results to using the porcine standard curve for measuring any titre of allo- or auto-antibody against FVIII in the Bethesda assay, using Hyate:C as the source of FVIII. These findings are of practical value when performing a porcine FVIII-based Bethesda assay.