Immunosuppressive therapy. 2

Efficient removal of abnormal immunoglobulin G from plasma of a multiple myeloma patient. Description of a new method for treatment of the hyperviscosity syndrome

Patients with multiple myeloma who have complications secondary to hyperviscosity are treated by chemotherapy and/or plasmapheresis. Because the response to chemotherapy is usually delayed, plasmapheresis is required for the removal of larger concentrations of plasma proteins to avoid life-threatening complications. Until now there has been no available means to decrease the abnormal plasma proteins in a selective manner. This report describes a new method for the selective removal of immunoglobulin G from the plasma of a patient suffering from IgG-type multiple myeloma. Results obtained from plasmapheresis and selective immunoadsorption of IgG are compared. It appears that the technique described herein may offer a new, more efficient method for the palliative treatment of diseases associated with elevated concentrations of plasma immunoglobulin G.

Cancer and teratogenesis: infrequent occurrence after medical use of immunosuppressive drugs

This study examines long term "medical" immunosuppression with azathioprine or cyclophosphamide for immunopathic disease in relation to cancer and foetal malformation. The experience represent an aggregate of 241 years of treatment and 508 patient-years of follow-up in 133 non-transplant patients. For azathioprine the mean duration of treatment was 1-9 years and the mean duration of observation was 3-8 years, and for cyclophosphamide, the mean durations of treatment and observation were 0-7 and 4-6 years. A sample of 70 patients was shown by in vivo tests to have significantly suppressed cell-mediated immunity. In the period of review there were observed two cancers, both squamous cell carcinomas of skin, two benign neoplasms and six keratoses; after the period of review, three further cancers were recorded, one being in a subject with a known previous cancer. Nine pregnancies with azathioprine yielded no foetal malformations.

Spontaneous and PHA stimulated lymphocyte transformation in multiple sclerosis patients during and after acute exacerbations with special reference to steroid therapy

Spontaneous (SLT) and phytochemagglutinin (PHA) stimulated lymphocyte transformation was studied in multiple sclerosis (MS) patients suffering from acute exacerbations or from the chronic progressive type of MS. The changes in cell-mediated immunity were also observed before, during and after immunosuppressive (prednisone) treatment. A total of 85 venous blood samples from 23 MS patients (11 males, 12 females) were included in the material. The controls consisted of 25 measurements from 17 healthy volunteers who served as normal controls. The pathological controls consisted of 13 patients with neurological diseases other than MS. All these and MS patients were hospitalized. The IUFdR uptake of the cells of MS patients was more rapid than that of the controls at 1-hr incorporation time in SLT. The difference decreased and was eliminated by longer incubation times (2-4 hrs). MS patients also differed from pathological controls in this sense. The reaction to PHA stimulation was lower both in the MS groups (64 per cent from the normal controls) and in the pathological controls. Within the different MS groups, significantly lower values were seen only in the samples of the patients receiving immunosuppressive therapy. Under prednisone (80-100 mg initial dosis) PHA stimulation values rapidly dropped within the first week and slowly returned within 2-4 weeks after the stopping of the corticosteroid treatment. In some cases, however, PHA values remained at a low level for several months. The significance of this finding for the understanding of the underlying pathogenetic mechanisms has to be studied in more detail.

Comparison of the immunosuppressive efficacy of 6-mercaptopurine, azathioprine, cyclophosphamide and 036.5122 (Asta) on the primary and secondary immune response of mice to sheep erythrocytes

Two alkylating (cyclophosphamide and 036.5122 Asta) and two antiproliferative agents (6-mercaptopurine and azathioprine) have been compared for their immuno-suppressive potency on the primary and secondary humoral immune response of mice. If equitoxic dosages of the respective drugs are compared, the alkylating agents proved to be of much higher immunosuppressive potency than the antiproliferative agents. In non toxic dosages alkylating agents were able to completely inhibit a primary or secondary immune response, whilst a similar effect with antiproliferative drugs could not be obtained even within toxic dose ranges. Induction of immunological tolerance was possible only by use of the alkylating agents. The significance of these comparative studies is discussed in view of the frequent use of the tested drugs in clinical immunosuppression.

Monitoring immune function during immunosuppressive therapy

Twenty-nine patients with a variety of connective tissue disorders were studied for the effects of immunosuppressive therapy on non-specific parameters of immune function. Baseline studies prior to therapy showed a frequent incidence of anergy (13%) lymphopenia (31%) and abnormal PHA response (43%). Despite these abnormalities in untreated patients it was possible to show an even higher incidence of anergy (31%), lymphopenia (66%) and abnormal PHA response (77%) following immunosuppressive treatment. The changes in lymphocyte count and PHA response were found to be statistically significant. It was found, paradoxically, that delayed hypersensitivity responses improved following institution of therapy in three patients. Clinical efficacy of immunosuppression correlated with lymphopenia and depressed PHA responses; in particular in the five patients with uncontrolled disease, these parameters were normal. Lymphocyte counts and PHA responses are the most simple and informative procedures to monitor immunosuppression in patients.

Kinetics of the reactive cell clones after immunosuppression and induction of tolerance: (1) inhibition of 19 S and 7 S plaque-forming cells in the primary and secondary immune response to sheep red blood cells by cyclophosphamide and 036.5122 (Asta)

The kinetics of the reactive cell clones after primary and secondary immunization with SRBC1) modified by cyclophosphamide and a newly synthesized cyclophosphamide analogue 036.5122 (Asta), have been studied. After primary immunization, both substances caused a severe and dose dependent depletion of 19 S PFC2). The 7 S PFC in the late primary response were only slightly inhibited by cyclophosphamide in low dose ranges, indicating, that sensitization could not be prevented by this substance. In contrast, 0.36.5122 was fully able to suppress 7 S PFC. Thus, treatment with 0.36.5122 after primary immunization can fully prevent the expression of the specific response. Experiments dealing with inhibition of a secondary immune response revealed that both test substances were able to strongly suppress the 19 S as well as the 7 S PFC. In general, 036.5122 demonstrates a higher suppressive potency, and the timing of its application for optimal suppression is less delicate than that of cyclophosphamide. 036.5122 was equally well inhibitory, whether given directly before or after antigenic challenge. The hypothesis is discussed, whether the immunosuppressive effect of 036.5122 given before antigenic challenge in the secondary immune response is due to cytotoxic damage of antigen reactive clones stimulated by persisting antigen.

Plasma exchange in the treatment of immune disease

Plasma exchange was investigated as an alternative to the use of toxic drugs to remove unwanted antibody. Studies in rabbits immunized with bovine serum albumin demonstrate that exchange transfusion after a primary immunization results in a rebound of antibody to above preexchange levels. However, exchange transfusion seven, 11, or 18 days after secondary immunization results in permanent lowering of antibody levels. Plasma exchange with the continuous flow centrifuge was used in four patients with hematologic diseases. White cell isoantibodies were removed in a septic leukopenic patient, permitting white cell transfusions. Two patients with immune thrombocytopenia were exchanges; one showed prompt and permanent elevation of platelet count, while the other did not improve. A patient with immune hemolytic anemia had stabilization of hemoglobin levels and decreased Coombs reactivity following plasma exchange.

Actinomycin D in the treatment of Paget's disease of bone

Fifteen patients with Paget's disease of bone were treated with actinomycin D for periods of up to 15 months. It was found that actinomycin D is effective in reducing the pain but not the neurological effects of Paget's disease. Careful adjustment of dose according to weight and initial response is necessary to prevent gastrointestinal side effects. If this is done, the risk of hepatic, renal, or haematological side effects is negligible.

The role of immunological factors in the treatment of cancer

Evidence has accumulated in the last 15 years that many experimentally-induced tumours in animals carry a tumour-specific transplantation-type antigen (TSTA) in their plasma membrane and that the tumour-bearing host responds to the TSTAs with the production of antibodies and cytotoxic mononuclear cells. In man the situation is not yet clear but there are indications that a similar situation may apply in many human malignancies. These findings have led to a resurgence in interest in the role of immunotherapy in the treatment of malignant disease, but as yet there is no clear evidence from properly controlled clinical trials that immunotherapy is the treatment of choice for any tumour. At present clinical immunotherapy constitutes a field for careful investigation but it cannot be considered a proven modality of treatment. At present its use must be confined to controlled studies in which benefit or possible harm can be determined. When giving immunotherapy it is necessary to monitor carefully the specific immune reaction of the host against the tumour. Further progress in immunotherapy requires a better understanding of why tumour cells succeed in vivo to escape destruction by the immune responses of the host. This review summarizes the current state of knowledge concerning the nature of TSTAs, the effect of the immune response to TSTAs on metastatic spread and the mechanisms of escape with special reference to the role which circulating soluble TSTA plays in 'neutralizing' the action of cytotoxic cells and antibodies. It is stressed that there is no support for the hypothesis of a 'blocking antibody'. Finally the different types of immunotherapy which have been developed in animal systems are described and possible clinical applications are discussed.