Plasmin inhibitor reduces T-cell lymphoid tumor growth by suppressing matrix metalloproteinase-9-dependent CD11b(+)/F4/80(+) myeloid cell recruitment.

Activation of the fibrinolytic system during lymphoma progression is a well-documented clinical phenomenon. But the mechanism by which the fibrinolytic system can modulate lymphoma progression has been elusive. The main fibrinolytic enzyme, plasminogen (Plg)/plasmin (Plm), can activate matrix metalloproteinases (MMPs), such as MMP-9, which has been linked to various malignancies. Here we provide the evidence that blockade of Plg reduces T-cell lymphoma growth by inhibiting MMP-9-dependent recruitment of CD11b(+)F4/80(+) myeloid cells locally within the lymphoma tissue. Genetic Plg deficiency and drug-mediated Plm blockade delayed T-cell lymphoma growth and diminished MMP-9-dependent CD11b(+)F4/80(+) myeloid cell infiltration into lymphoma tissues. A neutralizing antibody against CD11b inhibited T-cell lymphoma growth in vivo, which indicates that CD11b(+) myeloid cells have a role in T-cell lymphoma growth. Plg deficiency in T-cell lymphoma-bearing mice resulted in reduced plasma levels of the growth factors vascular endothelial growth-A and Kit ligand, both of which are known to enhance myeloid cell proliferation. Collectively, the data presented in this study demonstrate a previously undescribed role of Plm in lymphoproliferative disorders and provide strong evidence that specific blockade of Plg represents a promising approach for the regulation of T-cell lymphoma growth.

Single and combined effects of the vitamin D analogue KH1060 and cyclosporin A on mercuric-chloride-induced autoimmune disease in the BN rat.

Mercuric chloride induces in BN rats a self-limiting systemic autoimmune disease characterized by proliferation of autoreactive CD4+ T lymphocytes, polyclonal activation of B lymphocytes, and the development of an anti-glomerular basement membrane (GBM) nephritis with concomitant nephrotic range proteinuria. We have used this model of autoimmune disease to test the immunosuppressive ability of a novel vitamin D3 analogue KH1060. This compound prevents autoimmune manifestations including proteinuria, serum IgE, and serum anti-laminin antibodies in a dose-dependent manner, as does cyclosporin A (CyA). When dosages of KH1060 capable of partial reduction of proteinuria without causing significant hypercalcaemia are combined with small dosages of CyA also capable of partial prevention of proteinuria, an additive effect is seen, leading to complete prevention of proteinuria and substantial reductions in serum IgE and anti-laminin levels. Possible mechanisms of action are discussed and it is suggested that KH1060 could prove useful as an immunosuppressive agent in the treatment of autoimmune diseases.

False negative results in anti-HIV ELISA due to insufficient antigen coating of microtitre plates.

Since routine ELISA screening of blood donors for anti-HIV antibodies was introduced, much attention has been given to the specificity and the sensitivity of this assay. Most papers deal with false positive reactions while only a few have taken account of false negative results. We have found that insufficient HIV-antigen coating of the microtitre plates can lead to false negative results. It is essential that the producers of the ELISA test kits use control systems which guarantee sufficient antigen coating.

Plasma exchange in myasthenia gravis complicated with complement activation and urticarial reactions using fresh-frozen plasma as replacement solution.

6 patients with myasthenia gravis (MG) underwent 26 plasma exchanges (PE) using fresh-frozen plasma (FFP) as replacement solution. After each procedure, complement C3 conversion products (C3c) were detected in the plasma of all the patients. 3 patients had one or more attacks of urticaria during or immediately after the procedure. Using 5% albumin-saline solution as plasma replacement solution, complement activation and urticarial reactions were not seen. It is concluded that infusion of FFP to patients with MG should be avoided as it may induce complement activation and allergic reactions.

Autoimmune haemolytic anaemia treated with multiple transfusions, immunosuppressive therapy, plasma exchange, and desferrioxamine.

Severe autoimmune haemolytic anaemia in a five year old boy was unaffected by treatment with prednisone and splenectomy, but subsided after combined immunosuppressive therapy and three plasma exchanges. Over five months, a total of 93 transfusions of concentrated erythrocytes was given (equal to 18.6 grams of iron or 1.1 g/kg BW). This resulted in severe iron overload with cardiac, hepatic, and pancreatic complications, together with growth-retardation. These complications disappeared after treatment with desferrioxamine and vitamin C, but despite a normal growth hormone response to glucagon the concentration of somatomedin in serum remained low. Treatment by plasma exchanges and immunosuppressive agents may therefore be of value in severe haemolytic anaemia refractory to corticosteroids and splenectomy. Iron chelating therapy should be considered if multiple transfusions result in iron overload.

A single step immunoelectrophoresis method for the quantitation of complement C3c in biological fluids.

An intermediate gel rocket immunoelectrophoresis (IRI) suitable for direct quantitation of complement split products with C3c specificity is described. The technique represents a simple, quick, and reproducible method for the assessment of complement activity in biological fluids in diseases. The advantages of the quantitative approach of the IRI method as compared to the conventional crossed immunoelectrophoresis (CIE) are the increased sensitivity, specificity, and precision of the method; also, the assay capacity is superior to CIE. The IRI-C3c assay is therefore highly suitable as a scientific tool, and may also be useful for routine laboratory investigations.

Rapid improvement of myasthenia gravis after plasma exchange.

Neuromuscular transmission and the staircase phenomenon in the adductor pollicis muscle were studied in six patients with myasthenia gravis before and 24 hours after single plasma exchanges given in short series over one to four weeks. An improvement in neuromuscular transmission was observed in all patients but one within 24 hours, suggesting that an immunological block of receptor sites is reversible or that acetylcholine receptors are rapidly resynthesized. In addition to a neuromuscular transmission defect, two of the patients also showed evidence of impaired excitation-contraction coupling with a negative staircase phenomenon and reduced posttetanic twitch potentiation. This condition became normal after plasma exchange, which may indicate that a reversible immunological impairment of the sarcoplasmic reticulum was present. Improvement lasted up to several months. The anti-acetylcholine receptor antibody titers were lowered in response to single plasma exchanges, but actual titer levels showed poor correlation with clinical and electrophysiological changes.

Effect of in vitro X-irradiation on lymphocyte and granulocyte function.

Granulocyte transfusions have been complicated by graft-versus-host disease (GVHD) in the recipients. This risk can be eliminated by irradiation of the cell product. The effect of in vitro irradiation on elements of lymphocyte and granulocyte function was therefore studied in order to determine the dose of irradiation which blocked lymphocyte function without affecting the function of granulocytes. Lymphocyte blast transformation after stimulation with mitogens was reduced by 90% after irradiation with 1500 rad and by 97% after 5 000 rad. The response to microbial agents and allogeneic cells was far more radio-sensitive, being completely abolished after irradiation with 1 000 and 500 rad, respectively. Mobility was the function of polymorphonuclear leucocytes (PMN) most affected by irradiation, being slightly but significantly reduced after irradiation with 10 000-20 000 rad. The bactericidal activity was reduced only after irradiation with 40 000 rad or more, while the hexose monophosphate shunt activity and the myeloperoxidase activity were largely unaffected by irradiation with doses of up to 120 000 rad. Hence the results indicate that the irradiation of leucocytes intended for transfusion with a dose of 2 000 rad is likely to prevent GVHD without causing any apparent damage to the PMN.

A critical review of platelet yield by Haemonetics 30 . Based on literature and own observations.

By means of a haemonetics 30 cell separator platelets were collected for transfusion purposes from 18 different blood donors. A median yield of 5.7 X 10(11) platelets was obtained. The yield of platelets was found to be linearly related to the donors' initial platelet counts. The procedures were standardized by using one size of bowl (225 ml), performing 10 cycles per procedure, and performing all cycles as uniformly as possible. The median time per procedure was 118 min. Mild donor reactions were seen in 8 donors (44%) consisting of circumoral tingling. The decrement in the donors' platelet count was 86 X 10(9)/1, 37% of the initial platelet counts. The choice of the bowl size of 225 ml is motivated. The absurdity of the expression of yield pe h of processing, and of yield per 1 of blood processed is discussed. Furthermore, it is shown, that neither the fall in haematocrit nor the fall in the platelet count during the procedure are linear. The formulas commonly used for calculating the blood volume and platelet extraction efficiency, which are based on these assumptions, cannot therefore, in our opinion, be used.

Refractory Pneumocystis carinii infection in chronic granulomatous disease: successful treatment with granulocytes.

Pneumocystis carinii pneumonia developed in an 11-year-old girl with chronic granulomatous disease who had normal cellular and humoral immunity. The patient remained febrile during treatment with sulfamethoxazole-trimethoprim and pentamidine but became afebrile when treated with a series of 12 granulocyte transfusions combined with sulfamethoxazole-trimethoprim. In addition to documenting P carinii infection in chronic granulomatous disease our findings suggest that granulocyte transfusions may be of value in the treatment of severe infections in chronic granulomatous disease.

Harvesting of granulocytes for transfusion therapy by haemonetics 30. Yield, morphology and in vitro functions of collected granulocytes.

By means of a Haemonetics 30 blood cell separator white blood cells (WBC) were collected for transfusion purposes from 21 normal unstimulated donors. Citrated Hydroxyethyl Starch (HES) was used as anticoagulant. A mean yield of 1.13 x 10(10) WBC was obtained in 2 1/2-3 h. Half of the collected WBC were PMN cells containing a few per cent band forms, the other half lymphocytes and monocytes (12%). No shift in the distribution of WBC was found during the leucapheresis. Light and electron microscopy did not reveal any damage or changes in the structure of the processed granulocytes. The Trypan blue exclusion test showed 99% vital cells. In vitro assessment of the chemotactic and bactericidal activity of the collected granulocytes showed normal function. Also the content of myeloperoxidase was within normal range.

Post-transfusion purpura treated with plasma exchange by haemonetics cell separator. A case report.

A case of post-transfusion purpura in a 61-year-old, multiparous female with a platelet alloantibody (anti-Zwa) in her serum is reported. The patient was successfully treated with plasma exchange by means of a Haemonetics 30 cell separator and corticosteroids. Compared with other therapeutic measures, plasma exchange seems to shorten the duration of thrombocytopenia. Major surgery was possible in our patient within ten days of development of the syndrome.