Biologics are specialised & advanced injectable drugs which target the culprit chemicals responsible for the autoimmune destruction of any organ system. Use of Biologics over last decade have revolutionised the management of Rheumatological diseases. This article attempts to answer all questions that are commonly asked by patients regarding Biologics.
What are Biologics?
Biologics are drugs (Usually injectable) which are manufactured in a complex advanced biotechnological environment which have extreme precision in blocking or inactivating the culprit molecules or chemicals that cause autoimmune damage in Rheumatological diseases. e.g Etanercept is a biological drug that blocks the harmful action of the culprit chemical (also known as cytokines) named TNF alfa and is used in management of Ankylosing Spondylitis and many other rheumatological diseases.
Which Rheumatological diseases are treated with Biologics?
Most of the Rheumatological diseases are treated with biologics. The common ones are Rheumatoid Arthritis, Ankylosing Spondylitis, SLE, Psoriasis, Psoriatic Arthritis, Sjogren’s Syndrome, Vasculitis, Juvenile Immune Arthritis, Scleroderma, Ulcerative Colitis, Uveitis, Inflammatory Myositis and so on.
Can Biologics cure the rheumatological disease?
No, they can’t cure a person of the disease. This is because , most of the rheumatological diseases are caused by autoimmune phenomenon. By autoimmune phenomenon it is meant that our own immune system which is destined to kill and eradicate bacteria, virus & other microbes which cause disease to us, unfortunately are misdirected against our own organs and cause serious destruction to them. The destruction and damage done by the immune system is mostly mediated by toxic chemicals (which are completely non-toxic to the organs of a normal person) known as cytokines. Biologics when injected in our body, either target these cytokines and block their action or they inactivate the cells of the immune system so that they are no more capable of releasing the toxic cytokines. However, this inactivation is not permanent as the biologics themselves being drugs , do not stay in the body for long and they have their own half lives after which, the cells of immune system repopulate and start releasing the misdirected toxic cytokines causing continuation of the autoimmune damage. Thus, Biologics need to used continuously to achieve silence of autoimmune damage.
How long do we need to get treated with Biologics?
As already mentioned in the previous post and also as per the researchers, they is no limited time frame of use of Biologics. They ideally are needed to be used lifelong. It has often been found that use of Biologics for a short period (suppose 6 to 9 months) have resulted in sustained remission (absence of any disease) for a significant period of time but the disease DO tend to come back causing damage to organs after that period of remission. Hence, as per standard international guidelines, Biologics need to be used lifelong.
What are the side effects/adverse effects of Biologics?
There are certain common adverse effects of Biologics. Biologic drugs inactivate toxic cytokines which are misdirected against our own body. However, even in a person with rheumatological disease, these toxic cytokines, apart from causing autoimmune damage to the organs, play an extremely vital role in normal immune combat against the external microbes, bacteria, virus and other harmful organisms there by maintaining the normal immune defence of the body. Thus , inactivating these immune cells and cytokines can impair the normal immune defence of the person to external or even hidden internal microbes. Dormant illnesses (organisms that hide in the body without causing any overt disease) can manifest as full blown disease if Biologics are used without ruling out the presence of dormant diseases. One such example is Latent Tuberculosis Infection. Some others are Hepatitis B, Hepatitis C and HIV. Thus, if a person who harbours Tuberculosis bacteria in his body (Extremely common in South Asian countries like India, Bangladesh & Pakistan) although with no overt disease (also known as Latent Tuberculosis Infection :LTBI) is started on Biologic injections, there are significant chances that there will be reactivation of these dormant tuberculosis bacteria ( which were actually suppressed due to normal immune activity of the body) and cause a florid Tuberculosis of a particular organ. Similar situation might arise with patients who are silent careers of Hepatitis B, Hepatitis C and HIV.
External Infections: Patients on Biologics DO have little bit higher risk of acquiring external infections. The commonest external infections are Sore Throat, Common Flu, Viral Pharyngitis and Sinusitis and sometimes Herpes. This risk of external infections are more in patients who already are on immunosuppresants and those who are aged more than 65years. If used in children, e.g. for Juvenile Immune Arthritis, it should be ensured that they have updated vaccination schedule.
Hematological: (Frequency <1%)Use of Biologics have been associated with changes in blood counts. They include reduction in White Cell Count (Leucopenia), Platelet Count (Thrombocytopenia) or sometimes reduction of all cells of the blood(Pancytopenia).
Neurological: The package inserts of Biologics do have a black box warning stating that there are possible increased risk of demyelinating neurologic disorders which include multiple sclerosis, optic neuritis and Guillain-Barre Syndromes. These data are based on post marketing adverse affect reporting.
Malignancy: Extremely rare cases of lymphoma, Leukemia & other blood related malignancies have been reported. Concomitant use of drugs like Azathioprine increases the risk of these malignancies. Whatever, little evidence is available in development of malignancies , they have been found to occur in children and adolescents. The incidence of these cases is minuscule however, the manufacturer of the Biologics do need to report these kind of adverse events if any to the USFDA.
What tests are necessary before treatment with Biologics?
For children and adolescents: It has to be ensured that they are well up to date with the standard national vaccination sschedule.
For all: Tests for Latent Tuberculosis Infection (LTBI) such as 10 TU Mantoux Test, Interferon Gamma Release Assay (IGRA or Quantiferom TB), Chest X Ray and for Hepatitis and HIV, HbsAg, IgM Anti HCV & HIV I and II Antibody tests need to be done prior initiation of Biologics.
