Medical Biotechnology (BIOT 412) Human Diseases Assignment Muhammad Adeel Department of Biological Sciences FORMAN CHRISTIAN COLLEGE LAHORE (A CHARTERED UNIVERSITY) Assignment # 1 Human Diseases (Rheumatoid Arthritis) Name: Muhammad Adeel Roll No: 12-10004 Course: BIOT 412 Instructor: Dr. Leslye Johnson Medical Biotechnology (BIOT 412) Human Diseases Assignment Muhammad Adeel Human Disease: Rheumatoid Arthritis (RA) Section A: What is it? In a very simple manner, Rheumatoid Arthritis can be described as a chronic multisystem disease that causes the inflammation of joints and its surrounding tissues as well. The area of infection can spread to other areas than the joints as well. It is a well known example of auto immune disorders, in which the body’s own cells are attacked by the immune system. In this case the lymphocytic infiltration of the synovium (soft tissue lining the non cartilaginous surface in joints) takes place. Since the disease can spread to other areas of the body, it has been labeled as a systemic disease. 1. Pathogenesis While it has been known that the disease is mediated immunologically, the actual mechanism of triggering it is unknown. Some have labeled pathogens like virus and bacteria for the initiation, but no tangible study has been formed. However both, genetic and environmental factors are involved in this disease. The role of human leukocyte antigen has been recognized in the pathogenesis. A serotype of this major histocompatibility complex, HLA DR 4 is known to be involved. Initially the disease would affect the synovial membrane and destroy the joint system symmetrically. On a systemic level, it goes on to affect the pulmonary, ocular, vascular and other organs as well. The figure below shows a normal joint: Medical Biotechnology (BIOT 412) Human Diseases Assignment Muhammad Adeel As the disease progresses, it can lead to disruption of the tendons, and that of course, would limit the movement of joints. On another level, a certain level of deformity would exist. (Fauci et al., 2009) The deformation is caused by the release of a significant number of cytokines. Apart from this effector molecules are also released, which increase the inflammation. The method of inflammation can be direct or indirect. In both cases, the end result is the degradation of collagen and preteoglycans. Macrophages release enzymes that have increase number of neutrophils in the area, adding to the pathogenesis process. The autoantibody released in the process is known as the Rheumatoid Factor (RhF). These factors and an immunoglobulin (Ig G) form complexes that lead to the disease process. Citrulline antibody is another factor involved in the process. The figure below shows a deformed hand that has been affected with RA. The other figure is of an inflamed joint. (Marshall & Haynes, 2005) 2. Parts of Body Affected As mentioned earlier, it is a systemic illness, so all major organs of the body would be infected if the inflammation spread. However the major regions include: wrists, hands, elbows, shoulders, knees, ankles, etc Apart from this, the skin, lungs and heart can also be affected. 3. Genetic or Environmental? After much study on RA, it has been shown that both genetic and environmental factors are involved. Research has shown that factors like genetic variance, incomplete penetrance and Medical Biotechnology (BIOT 412) Human Diseases Assignment Muhammad Adeel multiple gene involvement do play a role in RA. As hinted earlier, HLA genes have a major role to play in the progress of this disease. (Nakaoka et.al, 2011) Research has also shown that environmental factors can also make people vulnerable to RA. A research has shown that habits like smoking can lead to RA. The reason cited is that the smoking causes change in the proteins related to the immune system and this can lead to the settling in of an auto immune disorder like RA. (John, 2009) As mentioned earlier Rheumatoid factors are released against body’s own tissues. This factor is basically a part (Fc) of an immunoglobin, IgG. Together they form immune complexes that cause pathogenesis. This factor can be precipitated on cooling the blood sample and are therefore referred to as cryoglobulin. 4. Symptoms RA is basically characterized by a symmetrical inflammation of the joints. This means that joints on the both side of the body would be equally affected. The major thing to be understood about the symptoms of the disease is that they are dependent on the type of inflammation. RA has tow levels: active and inactive. In active type, the inflammation is very much there and so are the symptoms. In case of inactive, the inflammation is less and the symptoms go into remission. The return of inflammation can happen any time and is known as a relapse or flare. During the active state of the disease, the symptoms are as follows: Fatigue, loss in hunger, low intensity fever, pain in muscles & joints, stiffness (this symptom is quite notable during the morning time). Due to the inflammation, the joints would turn red, become swollen and cause extreme pain. Similar symptoms would include difficulty in turning door knobs or twisting your hand, presence of nodule on the posterior side of the skin, numbness, chest pain among others. Since it is a systemic illness, burning in eyes, drying of mouth and pleurisy are also symptoms of RA. Section B) Understanding from Genetics’ Perspective Using the genetics perspective, researchers were able to understand the role of a serotype of HLA, HLA DR4 in the causing of the immune response against bodies own antigens. They Medical Biotechnology (BIOT 412) Human Diseases Assignment Muhammad Adeel were also able to use techniques like DNA sequencing and molecular based typing to conclude the role of D region in the disease. The research pointed out, “Using DNA sequencing and molecular-based typing, it has been demonstrated that the disease-conferring portion of the D region is confined to a short sequence within the third hypervariable region of HLA-DRB1 gene which includes the amino acid positions 67 through 74. The HLA genes and gender constitute about 30% of the genetic risk in RA, while other genetic factors such as cytokine genes, germline genes, and T-cell receptors also account for some of the genetic predisposition to RA.” (Marshall & Haynes, 2005) Section C) Population Effected It is now a well established fact that women are affected at least three times more than men. As per statistics available, it occurs in 0.8% of the population. Majority of the people affected from RA are in their 40’s and 50’s. However this doesn’t mean that only old people are affected by it, since RA can occur at any age. Juvenile RA is a term referred to young people affected by RA. The prevalence of this disease progresses with age. In Pakistan, at least 8% of the population suffers from joint pain. The exact numbers who suffer from RA is unknown owing to various reasons. Surveys have not been much beneficial here, since people often are unwilling to reveal illnesses. However, the data collected via cross sectional studies has shown that a major portion of the elderly population suffers. Women, of course, face the major brunt of it. However, the ratio is less or equal to developed nations like U.K or U.S.A. (Akhtar et al., 2011) Section D) Diagnostics, Prevention and Treatment 1. Diagnostics It is imperative to know that a single standard test has not been made for detecting RA at its initial stage. Usually a combination of imaging and blood tests is done to arrive at a standard conclusion. Rheumatoid Factor presence cannot be taken as a yardstick for any immunological study pertaining to RA since it is present in other diseases like HCV, so the specificity of such a Medical Biotechnology (BIOT 412) Human Diseases Assignment Muhammad Adeel test would be significantly low. An assay has been developed, which would be discussed in the last section. Let us take a look at these diagnostics: A) Blood Tests Blood tests can be used to measure the degree of inflammation. Most often used tests include: Erythrocyte sedimentation rate (ESR) and C-reactive Protein (CRP) When the value of both these factors is high, inflammation is present. Also the color of synovial fluid during inflammation changes, and can be viewed in the figure below: B) Imaging An X-ray would also show if the joint has been inflamed by RA. It has been shown that x ray of feet is more effective in showing the presence of RA. Doctors have also agreed that better imaging techniques like magnetic resonance imaging and ultrasound scans produce better diagnosis. 2. Treatment A permanent cure for RA has not been found yet, however advancement in usage of antibody therapy is there. It would be discussed in the last section. The goal of treatment is to lessen the pain and improve the function of joints. Doctors are resilient on the fact that earlier diagnosis can lead to lessening of pain to a great extent. The range of treatment can be divided into four segments: Medical Biotechnology (BIOT 412) Human Diseases Assignment A) Drugs B)Physical Therapy C) Surgery Muhammad Adeel D)Biological Therapy We shall take a look at each aspect now. A) Drugs For quite some time, drugs have been in use for the treatment of RA. Mostly doctors would prescribe a combination of 2, 3 drugs to lessen the pain. The dosage and the kind of drug depend on the activeness of the RA in the patient. Major classes of drug being used in such cases are analgesics and non steroidal anti-inflammatory drugs (NSAID’s). Pain Killers are basically given to help the other drug to its task by lessening the pain in the patient. NSAID’s are quite effective in terms of relieving pain, but their efficacy is short term. These can be in the form of capsules or gel that can be applied on affected areas. Another class of drug being used these days is the disease modifying anti-rheumatic drugs (DMARD’s). The basic target of these drugs is not to lessen pain but to address the main disease. Examples would include gold injections and sulfasalazine among others. Some of them are immunosuppressant as well, and limit the RF production. Steroids are also given to reduce inflammation; however they should be used with care owing to their side effects. (Fauci et al., 2009) B) Physical Therapy In places where drugs can be harmful owing to side effects, physical therapy can be used. In this procedure the working of joints is maintained with exercise. In such cases, patients are assigned a physiotherapist who would suggest different exercises over a specific period of time. C) Surgery If the disease has been detected in an earlier stage, the doctor would opt for a surgery. The scope and magnitude of surgery varies from patient to patient. In certain cases, the synovium is removed to prevent further inflammation. In old patients, joint replacement surgery can also be performed. D) Biological Therapy Biological therapies were developed during the last two decades and are focused on addressing the immune system’s involvement in the disease. The therapy involves the usage of molecules Medical Biotechnology (BIOT 412) Human Diseases Assignment Muhammad Adeel that can target immune system factors. A known class of molecule being used these days is the anti-TNF drugs and they are being used against tumor necrosis factor (involved in inflammation). Other classes target other factors like CD3 or CD 22. The principle is that they would inhibit the release of such auto immune factors. (Takeuchi, 2011) Section E) Recent Development (Major Research Questions) A major research question that can be thought of in terms of recent therapeutic revolution is that “Is the cure of RA a realistic goal?” A paper published in 2009, indicated to the fact that disease remission is an actual possibility. Apart from this, it also suggested that advances in molecular biology have lead to understanding of the disease and developing a possible cure. In this section, we would take a look at these research innovations: 1. Innovation in Diagnosis Advancement in molecular biology has lead to a very specific diagnostic measure for RA, which is now known as Anti MCV Antibody Test. It focuses on detecting the autoantibodies produced against a protein family known as citrullinated vimentin. It is basically a point of care testing immunoassay that would detect a mutated form of these proteins. The specificity of this test is as high as 99.7%, which is quite great. 2. Innovation in Treatment As mentioned earlier, biological molecules are now being applied against the immune response. Another region of innovation that can lead to a permanent cure or at least remission of the disease is the antibody therapy (Hay & Olewyn, 2004). These monoclonal antibodies can be divided into four categories: 1. Chimeric 2. Humanized 3. Fully Human 4. Fusion Proteins Their function is limiting the effect caused by the immune system against its own body tissues. Further development is now being made in these monoclonal antibodies by altering their glycobiology. It is now known that by altering the sugar structure of the antibody, better molecules can be made. This has been implemented in the case of a molecule rituximab, which has been glycol-engineered for enhancing its activity.(Isaac, 2009) Medical Biotechnology (BIOT 412) Human Diseases Assignment Muhammad Adeel References Akhtar, E, Bilal, S & Haque, U (2011) “Prevalence of Arthritis in India & Pakistan”, Rheumatology International, 33: 849-55 Bartold, PM, Marshall, RI and Haynes D.R (2005) “Peridontitis & Rheumatoid Arthritis”, J Periodontal, 76: 2066-74 Fauci, AS, Braunwald, E, Kasper DL, Hauser, SL, Longo, DL, Jameson JL, Loscalzo, J. (2009) Harrison’s Manual Of Medicine. McGraw Hill: New York, 886-888 Hameed, K & Gibson, T (1997). “A comparison of the prevalence of rheumatoid arthritis and other rheumatic diseases amongst Pakistanis living in England & Pakistan”. British Journal of Rheumatology 36: 781-185 Hay, FC & Westwood MR Olwyn, (2002) Practical Immunology, 4th Edition. Blackwell Science: New York: 76 Isaacs, D John (2009) “Antibody engineering to develop new antirheumatic therapies”, Arthritis Research & Therapy. 11: 225-229 Nakaoka, H, Cui, T, Tajima A, Oka, A, Mitsunaga, S, Kashiwase, K, Homma, Y, Sato, S, Suzuki, Y, Inoko, H & Inoue, I (2011) “ A systems genetics approach provides a bridge from discovered genetic variants to biological pathways in rheumatoid arthritis”. PLoS One: 9: 1-16 Takeuchi, T (2011) “Revolutionary change in rheumatoid arthritis management with biological therapy” Keio Med 60: 75-81 Web Resource Used: Statistics of RA in Pakistan: http://www.mendeley.com/research/prevalence-arthritis-indiapakistan-review/ On immunoassay of RA: http://acr.confex.com/acr/2008/webprogram/Paper2009.html Figures from: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001467/