General Types of Immunotherapy - Coursework Example

INTRODUCTION Although still far from being perfected, immunotherapy, as a way to treat human maladies either just by itself or in tandem with other maladies, has been gaining ground. As this kind of therapy capitalizes on the human “natural defense system,” its ensuing development is significantly dependent on the depth of our understanding of our immune system. This paper presents the essential information about the field of immunotherapy and provides a couple of examples of immunotherapy’s medical application – that is, concrete cases where immunotherapy was done. THE FIELD OF IMMUNOTHERAPY Immunotherapy is a treatment procedure that capitalizes on the potentials of the human body’s natural immune system to fight disease (see Ball & Kagan 2008, pp. 38). As a treatment that stimulates or refurbishes the capability of our inherent bodily defense system to fight infection and disease, immunotherapy – likewise called biological therapy or bio-therapy – employs substances called biological response modifiers, which are may be produced in the laboratory to treat cancner, rheumatoid arthritis, and other diseases. Since the nineteenth century when the power of the human immune system to treat sickness initially came to the surface, immunotherapy – although, to date, it’s still far from being perfected – has been considered promising therapy or treatment procedure especially for cancer (cf. Bhardway 2007; Curiel 2007, pp. 1172; see also Sica & Bronte 2007), allergies (Josephson 2006, pp. 156-159; see specifically Denburg 1998, pp. 220), asthma (see Walsh & McDougall 2008, pp. 165-171; Ahrens, Straube-Koerbler, & Lettgen 2008, pp. S75; Yeadon & Diamant 2000, pp. 354-355) – among others. Basically, immunotherapy is an attempt to get the immune system to react to, for instance, as in the case of cancer immunotherapy, the cancer cells as if they were foreign – and, hence, needed to be eliminated, rejected or suppressed. Essentially, the body’s immune system distinguishes and attacks bacteria and/or other foreign elements that it finds within the human body system. Then, the immune system produces antibodies that lock up and labels the cancer cells – facilitating their eventual destruction by another special cells that are from the immune system. However, the human immune system does not always suffice to battle bacteria alone. For this immunotherapy – which may be by pills, intravenous or injection – becomes of help. Immunotherapy either stimulates the immune system to fight the bacteria or enhances the body’s normal defense system reaction to a disease threat. The chemicals that are made to modify biological response are either inherent in the body or are produced in laboratory. A state of “immunocompromised” or lessened efficacy of the immune system may also be deliberately induced for various reasons. Known as immunosuppression, this is done to prevent the body from rejecting a transplanted organ, or for treatment of rheumatoid arthritis – among others. Currently, there are cortisone, azathioprine and cyclosporine as immunosuppresants. Immunotherapy is sometimes used by itself. But, usually, it is used as an adjuvant to another primary therapy – that is, to supplement and/or complement the anticancer effects of the primary therapy. For instance, immunotherapy lessens the side effects of radiation or chemotherapy. Slowly but surely developing field The inception of immunotherapy may be traced as far back as 1859 with Louis Pasteur’s defining experimentation that eventually reported on protective effects of vaccines, whereby Pasteur was able to show that spontaneous generation (of disease) was actually a consequence of airborne microorganisms. When Pasteur’s breakthrough was complemented by Robert Koch’s painstaking characterization of bacteria and bacterial infection, the germ theory of disease and the seminal field of immunology were established by the end of the 19th century (Kaufmann & Wolchok 2007, pp. 4-5). Concomitant to these formative years of the field of immunology, there was a New York City surgeon by the name of William Coley. Conventionally, he is known to have been the first to recognize the potential role of the immune system (in cancer treatment). In the late eighteenth century, he treated cancer patients by deliberately infecting them with a certain kind of bacteria that eventually came to be known as Coley toxins. He is likewise said to have devised a vaccine stuffed with killed bacteria that instigates tumor killing. Subsequently, he reported successful cases of tumor regression in his patients – which attributed to antecedent bacterial infection (see Curiel 2007, pp. 1167). Similarly, in Europe in the middle of nineteenth century, doctors noticed that tumors would shrink if these were infected. Besides, medical professionals were taking inspiration from the successful smallpox vaccine that “cancer vaccines” were attempted to produce too. These attempts were ineffective, but were instrumental in bringing about the field of immunotherapy. The initial development of immunotherapy, however, was very slow; or, differently expressed, the state of immunotherapy is still to get pass over the state of being investigational (see Ball & Kagan 2008, pp. 38). With Coley’s findings overshadowed by other forms of (cancer) treatment, over a hundred year’s work in the laboratory yielded little success too. In fact, it was only in 1975 that Georges Koehler and Cesar Milstein made synthetic antibodies; in 1976, a fuller understanding of tumor recognition and rejection at the cellular and molecular levels was reached and the T cell growth factor (IL-2) identified and cloned; and in 1980’s, interferon-alpha was known to cure tumors of patients with low-grade lymphoma. From then on, researchers have made important progress in this field. And as the cells and molecules of the immune system are better understood, immunotherapy is expectedly going to be much furthered as its development has shown its growth from somewhat cryptic field of just a few professionals and experts into an immense academic discipline whose fundamental doctrines filter through all other aspects and areas of clinical medicine (see Brown & Kirkwood 2001, pp. 3-25). General types of immunotherapy Now, immunotherapy realizes its intended purpose by two general strategies. Firstly, there is what is called “active” immunotherapy (see Souba & Wilmore 2001, pp. 505) and “passive” immunotherapy (see Shors 2009, pp. 168-169). The former seeks to improve the immune response by stimulating the patients’ existing immune system by treating it with modulators such as adjuvants and vaccines (see Crowley 2009, pp. 210). The latter, also called “adoptive” immunotherapy, provides new components – that is, synthetic substances – to replace or add to the patients’ immune system by transferring or transfusing to the patients antibodies or cells (see Park & Mitchell 2008, pp. 88; see also June 2007, pp. 1204). A popular form of passive immunotherapy is monoclonal antibody therapy, where antibodies are created inside a medical laboratory and injected into the patient’s vein. Immunotherapy may be “specific” or “non-specific,” as well (Crowley 2009, pp. 211 and 224). It is specific or targeted if it is directed against a particular target (the antigen). This strategy includes most cancer vaccines and all monoclonal antibodies. Alternatively, immunotherapy can be directed to augment or improve the immune system’s effectiveness in general. This non-specific strategy includes treatment with cytokines such as interferon and interleukin-2 (IL-2) (Park & Mitchell 2008, pp. 88; Ball & Kagan 2008, pp. 38). The involved biological agents From the preceding, it becomes understandable that immunotherapy is involving biological agents that generally are additional immune cells or immune signaling molecules. Thus, it avails of T cells that directly or indirectly recognize or destroy problem cells (see the findings of Shen et al. 2007). Immunotherapy may also draw on monoclonal antibodies, such as the B cells that produce antibodies against viruses, bacteria, toxins and even other cells that are specified to be inherently foreign to one’s body system. Further, cytokines – the chemical messengers between various parts or among cells of the immune system -- are also being employed – e.g., interleukins-2 (IL-2) and interferons (Park & Mitchell 2008, pp. 89-91; see Bhardwaj 2007, pp. 1130). To date, there are studies involving Interleukin-2 and interferon as these biological response modifiers are being considered in terms of their potential to treat advanced malignant melanoma. Interferon is now being used to treat hepatitis C. Current state of immunotherapy and its offer of hope There is no doubt that immunotherapy is a potentially cutting edge treatment. However, much of what it is today is still in experimental or investigational phase (see Curiel 2007, pp. 1172). It promises to be the least toxic of treatments, but it is not free from different side effects depending on the type of treatment. These side effects may be weakness or feeling of exhaustion, loss of appetite, queasiness or nausea, vomiting, chilling, muscle or body aches, diarrhea, and fever or flu-like symptoms. Some patients may similarly report skin rashes; while others would easily bleed or get bruises. However, these side effects are easily contained and they normally head off once the treatment is stopped. Not all patients too are candidates for immunotherapy as it is not recommended for the cases of prostate and ovarian cancers and for smaller and earlier stages of cancer. EXAMPLES OF APPLICATION OF IMMUNOTHERAPY Now, we turn our attention to two applications of immunotherapy. We need to indicate in this paper that immunotherapy is actually being applied to deal with different illnesses, particularly with skin cancer and with allergies. The first would be about a high profile case that is going to break grounds in the field of immunotherapy for cancer cases, and the second is about an ordinary application of immunotherapy to address allergens. Immunotherapy for skin cancer In June 2008, Dr. Casian Yee rendered a report about the first successful treatment of a patient with advanced skin cancer. The skin cancer patient was treated by injections with immune cells cloned from his own immune system. The treatment was adoptive, and it lasted for eight weeks – after which he was pronounced to be cured from skin cancer. Yee’s successful use of adoptive therapy is an extension of his earlier works where he harvested cells from the peripheral blood, tumor sites, and drained lymph nodes and expanded effector cells in a specific or non-specific fashion for adoptive transfer (see Yee 2008). Generally, adoptive cell therapy (ACT) employs autologous tumor-infiltrating lymphocytes and is an effective treatment for patients with metastatic melanoma (cancer skin). Based on adoptive immunity, ACT is T cell-based cytotoxic response to attack cancer. T cells that have a natural or genetically engineered reactivity to patient’s cancer are expanded, cultured in vitro to make them more effective, and then adoptively transferred back into the cancer patient (see Yee 2008). Simplistically put, Yee’s (2008) approach of adoptive immunotherapy to harness the power of the immune system to seek and destroy cancer or tumor cells is realized by creating armies of T cells that are augmented to find and kill cancer cells. Yee (2008), in his specific application of immunotherapy, employed CD4 helper T cells as a means to augment in vivo persistence and the use of pre-infusion lymphodepletion to condition patients to adoptive transfer. The antigen-specific CD4 T cell clones were produced from Class II-restricted epitopes for tyrosinase and NY-ESO-1 from nine melanoma patients’ peripheral blood. These patients had advanced melanoma that was also obstinate to conventional therapy. They were treated in a dose escalation of a single infusion of antigen-specific CD4 T cells at cell doses of 109, 3.3 X 109 and 1010/m2. As a consequence, in some patients, Yee was able to observe the development of endogenous CD and CD8 T cell responses to non-targeted melanoma-associated antigens. CD 8 T cells destroy cells that have been infected with foreign invading micro organisms and produce antiviral substance (antibodies) that help fight off the foreign invader(s). This is accordingly an indication of localized recruitment of no-specific effectors by infused CD4 T cells that may have led to tumor killing. Immunotherapy for allergies Immunotherapy for allergies, more commonly known as allergy shot, is given to augment one’s tolerance to allergens – that is, the substances that provoke allergy symptoms. It is not panacea for allergies; it simply reduces one’s sensitivity to particular substances. The process, called desensitization, involves allergy extracts being shot into human bodies by allergist with progressively increasing dosages over time to facilitate the adjustment of the body to the allergen – eventually resulting to the body becoming less sensitive to the allergen. Normally, the first shots are made to contain small quantity of the allergen or antigen to which one is affected by (see Josephson 2006, pp. 157). Essentially, allergen immunotherapy works like a vaccine. One’s body responds to the injected amounts of a particular allergen, given in gradually increasing doses, by developing an immunity or tolerance to the allergen(s) (see Griffin 2009, pp. 46). As a result of these immune changes, immunotherapy can led to decreased, minimal or no allergy symptoms when one is exposed to the allergen(s) included in the allergy vaccine (Josephson 2006, pp. 157). Generally, immunotherapy to allergies follows a couple of phases. The first phase, called build-up phase, involves receiving injections with increasing amounts of the allergens. The frequency of injections during this phase generally ranges from one to two times a week – that is, unless a rapid build up schedules are used. This phase normally endures from three to six months. The second phase – termed maintenance phase – starts when the effective therapeutic does is reached. Different from person to person, the effectiveness of this phase depends on one’s level of allergen sensitivity and response to the immunotherapy build-up phase (Lockey & Ledford, 2008 pp. 323; see also Lee 2003, pp. 292). It is said that the effectiveness of immunotherapy is how severe is the person’s allergy and the quantity of substances a person is allergic to. In general terms, however, immunotherapy works very well for allergies to insects, pollens and dust mites, allergic asthma, molds and even pet dander. But, whether it’s efficacious to hives and/or food allergies is yet to be determined (see Hicks 2006, pp. 55). Besides the traditional allergy shots, scientists and medical practitioners are now proposing other new immunotherapy procedures. First, there is what is called rush immunotherapy, which involves more rapid – hence, rushed – build up to the maintenance dose of extract. Because in this procedure increasing doses of allergen are given every few hours rather than every few days or weeks, rush immunotherapy is posing a greater risk of body-wide reaction. On this account, rush immunotherapy is done under close medical supervision in hospitals. Second, there is oral immunotherapy. Also termed sublingual-swallow immunotherapy, it works by giving allergen extracts as drops, usually placed under the tongue and then swallowed (rather than through injections). And, third, there is intranasal immunotherapy (see Takabayashi et al. 2003; Lockey, Bukantz & Bousquet 2004, pp. 499). While it is specifically helpful in reducing nasal symptoms of rhinitis, its effect may not have the longer lasting benefits that have been associated with traditional immunotherapy. CONCLUSION Lest we have false hope, it is deemed necessary to point out as we round this paper up that while it is true that immunotherapy has, to date, been able to achieve some milestones, its progress is going to come in incremental basis – that is, its progress is going to be with us in step-by-step fashion. Besides, immunotherapy is very closely connected to our understanding of human immune system. Thus, our optimism for this cutting-edge therapy process must be tempered by realistic considerations. BIBLIOGRAPHY Agosti, JM & Sheffer, AL 2002, Biotherapeutic approaches to asthma, Informal HealthCare, London. Ahrens, PA, Straube-Koerbler, H & Lettgen, B 2008, Immunotherapy in children – evaluation of efficacy by using a quantitative allergen specific bronchial challenge test. The Journal of Allergy and Clinical Immunology, 121 (2), pp. S75. Ball, E & Kagan, A 2008, 100 questions and answers about Leukemia, 2nd ed., Jones and Batlett Publications, Sudbury. 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