Antibodies immunosuppressive action

DNA s5mthesis and also interfere with cell replication. Alkylating agents has got cytotoxic action and damage the nuclei of growing and multiplying cells. They have got immunosuppressant action also and suppress antibody production. They also have radiomimetic (like ionizing radiation) actions. 

The pathology of the infection is due to inflammatory changes associated with an induced autoimmune demyelination of nerve cells. Interestingly, the immunosuppressive action of components of the parasite s membrane are probably responsible for frequent secondary infections such as pneumonia. Liberation of common surface antigens (the mechanism involved in immune evasion) in every trypanolytic crisis (episode of trypanosome lysis) leads to antibody and cell-mediated hypersensitivity reactions. It is believed that some cytotoxic and pathological processes are the result of biochemical and immune mechanisms. 

In the past 20 years hundreds of Chinese traditional and herbal medicines with immunomodulating functions have been screened, and their active components studied. Through these studies, six diterpene lactone epoxide compounds, with antiinflammatory and immunosuppressive actions, were isolated from T. wilfordii. Zheng et al. [183] assayed the half-effective dose (ED50), the therapeutic index (TI) and a certain safety factor (CSF) using croton oil induced ear swelling and hemolysin-antibody formation mouse models and found that triptolide (79), tripdiolide (80), triptonide (81), tripchlorolide (92), and triptolidenol (93) possessed both antiinflammatory and immunosuppressive activities, while triptriolide (94) showed antiinflammatory action only. Fig. (28). The results of the TI and CSF of both activities clearly demonstrated that the antiinflammatory and immunosuppressive compounds in T. wilfordii are pluralistic and the differences in these compounds can be used as a base for the evaluation and selection of them. 

Muromonab-CD3 (Orthoclone OKT3) [Immunosuppressant/ Monoclonal Antibody] WARNING Can cause anaphylaxis monitor fluid status Uses Acute rejection following organ transplantation Action Murine Ab, blocks T-cell Fxn Dose Per protocol Adults. 5 mg/d IV for 10-14 d Peds. 0.1 mg/kg/d IV for 10-14 d Caution [C, /-] w/ Hx Szs, PRG, uncontrolled HTN Contra Murine sensitivity, fluid overload Disp Inj SE Anaphylaxis, pulm edema, fever/chills w/ 1st dose (premedicate w/ stCToid/APAP/antihistamine) Interactions t Effects W/ immunosuppressives t effects OF live virus vaccines t risk of CNS effects encephalopathy W/ indomethacin EMS Monitor for S/Sxs of Infxn monitor resp Fxn, known to... 

Astragalus Astragalus membranaceus) Uses Rx of resp infxns, enhancement of immune system, HF Action Root saponins t diuresis, -1- BP anti-inflammatory action related to the stimulation of macrophages, t antibody formation t T-lymphocyte proliferation Available forms Caps/tabs 1-4 g tid, PO Liq ext 4-8 mL/d (1 2 ratio) dry ext 250 mg (1 8 ratio) tid, PO Notes E Immunosuppression w/ doses >28 g Interactions t Effect OF acyclovir, anticoagulants, antihypertensives, antithrombotics, antipits, intCTleukin 2, intCTferon X effect OF cyclophosphamide EMS t Risk of bleeding... 

The anti-inflammatory and immunosuppressive effects of glucocorticoids are largely due to the actions described above. In humans, complement activation is unaltered, but its effects are inhibited. Antibody production can be reduced by large doses of steroids, although it is unaffected by moderate doses (eg, 20 mg/d of prednisone). 

When injected, azathioprine (Imuran) is rapidly converted to 6-mercaptopurine. The half-life of azathioprine after intravenous injection is 10 to 20 min, and that of 6-mercaptopurine is somewhat longer. The cytotoxic activity of these thiopurines is due to the conversion of mercaptopurine to 6-thiouric acid, a noncarcinostatic metabolite. This action is thought to block the excess synthesis of inosinic acid from its precursors, glutamine and phosphoribosylpyrophosphate. In addition, unlike cyclophosphamide, azathioprine is a potent anti-inflammatory substance that can cause a reduction in the number of monocytes and neutrophils at inflammatory sites. Antibody responses are also inhibited by azathioprine. Studies in humans have shown that azathioprine decreases the y-globulin and antibody levels, thus influencing IgG rather than IgM production. This makes azathioprine an effective immunosuppressant in the early phases of immune responses. It is less effective or completely ineffective in altering either the effector phase or already established reactivities. 

Gusperimus is a guanidine derivative with antitumor and immunosuppressive properties. Its mechanism of action is not well understood and may involve blockade of the maturation of B and T lymphocytes and monocytes, with inhibition of both cell-mediated and antibody-mediated immunity. In preliminary clinical trials in transplant patients, adverse effects at low doses included mild-to-moderate leukopenia, facial and perioral numbness, anorexia, gastrointestinal disturbances, facial flushing. 

Describe the mechanisms of action, clinical uses, and toxicities of antibodies used as immunosuppressants. 

Mechanism of action Rh GAM is a human IgG preparation that contains antibodies against red cell RhJD) antigens. Administration of this antibody to Rh (D)-negative. D -negative mothers at time of antigen exposure (ie, birth of an Rh (D)-positive, D -positive child) blocks the primaiy immune response to the foreign cells. The mechanism probably involves feedback immunosuppression. 

The drug enhanees elass I histoeompatibihty molecules on lymphocytes, increases the production of ILs-1 and -2, regulates antibody responses, and above all enhances NK cell activity. Besides, it also inhibits cancerous tumour-cell growth by virtue of its inherent ability to inhibit protein anabolism (synthesis) in vivo. The drug is antiproliferative and, therefore, may also serve as immunosuppressive. It is, however, pertinent to state here that the prevalent action of the drug upon the NK cells is believed to be the most important and critical factor for its prevailing antineoplastic profile. 

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