Diagnositic Utility of Serum Adenosine Deaminase and Liver Function Tests in Tuberculosis and Hiv Patients

Adenosine deaminase is a catabolic enzyme, of the purine catabolic pathway. The function of ADA also is related to the development of immune system and cell differentiation in human. The global incidence of tuberculosis (TB) has sharply increased particularly in areas where HIV and tuberculosis are both prevalent. The Adenosine deaminase activity was found to be elevated in the fluid sample of most of the suspected cases of Tuberculosis and HIV. But it has been observed that in the patients presented with typical clinical picture of tuberculosis infection and HIV, the adenosine deaminase activity in serum is much above the reference range. The Adenosine deaminase activity along with the lymphocyte to Neutrophils ratio, total leucocytes count and protein electrophoresis can be used as a diagnostic test for the diagnosis of HIV and HIV plus tuberculosis infection. The study consists of 37 patients with HIV infection, 33 patients with HIV and tuberculosis and 43 patients who suffered from tuberculosis and 25 normal subjects. All the serum samples were analyzed for ADA, Serum Total Proteins, Albumin, Globulin, Serum Alkaline Phosphatase, Serum Alanine Transaminase, Serum Aspartate Transaminase and Serum Total Bilirubin. HIV patients had significantly higher ADA levels compared to normal controls. TB Patients also had significantly higher ADA and Total Leucocyte count when compared to normal controls. Comparison of normal subjects with patients suffering with both HIV and TB showed that the patients had significantly higher ADA and Alkaline phosphatase levels. INTRODUCTION Though India is the second-most populous country in the world, India has more new TB cases annually than any other country. In 2011, out of the estimated global annual incidence of 9 million TB cases, 2.3 millions were estimated to have occurred in India, accounting for approximately one fifth of the global incidence. [1] Similarly there were approximately 34 [31.4–35.9] million people across the world living with HIV in 2011. Sub-Saharan Africa is the most affected region, with nearly 1 in every 20 adults living with HIV. Sixty nine per cent of all people living with HIV are living in this region. There is no cure for HIV infection. However, effective treatment with antiretroviral drugs can control the virus so that people with HIV patients can enjoy healthy and productive lives. [2] India has the third largest number of people living with HIV/ AIDS. As per the 2008-09 HIV estimates, there are an estimated 23.9 lakh people currently living with HIV/AIDS in India with an adult prevalence of 0.31 percent in 2009. [3] Among the states, Manipur has shown the highest estimated adult HIV prevalence (1.40%), followed by Andhra Pradesh (0.90%), Mizoram (0.81%), Nagaland (0.78%), Karnataka (0.63%) and Maharashtra (0.55%). Besides these states, Goa, Chandigarh, Gujarat, Punjab and Tamil Nadu have shown an estimated adult HIV prevalence greater than national prevalence (0.31%). Tuberculosis is the commonest opportunistic infection among people living with HIV and in several instances HIV and TB co-exist. The possibility of HIV infection in cases of tuberculosis and Vice-Versa, should be considered at all times. In 2011 worldwide 430,000 people were estimated to have died of TB and HIV co-infection, in addition to the 990,000 people who died from TB alone. It has been seen that AIDS with a co-infection of tuberculosis exist more predominantly in the lower economic group of people. In resource-poor settings, smear negative TB is difficult to diagnose and also difficult to exclude especially in HIV infected patient. [4] There are a few numbers of tests available for the diagnosis of tuberculosis, such as Adenosine deaminase activity, polymerase chain reaction, Interferon gamma and Lysozyme. There is also microbiological confirmation of the microorganisms i.e. culturing of the fluid obtained, looking out for the Acid fact bacilli in the sputum or fluid. The various tests for the diagnosis of tuberculosis, Polymerase Chain Reaction (PCR), is expensive and is not found to be more sensitive to pleural fluid. Thus the only test left is Adenosine deaminase Activity (ADA). This is a single test which is sensitive and specific and at the same time inexpensive and easy to perform [5]. Adenosine deaminase (ADA) is a hydrolase enzyme, polymorphic and actively participates in the metabolism of adenine nucleotides. This enzyme catalyzes hydrolytic de-amination of adenosine and deoxyadenosine to inosine and deoxyinosine respectively; in this process ammonia is released. ADA modulates the concentration of adenosine which is both a metabolic precursor for nucleic acids (intracellular) and significant signaling molecule involved in the regulation of various physiological processes. Lymphoid tissue has 10 to 20 time’s higher adenosine deaminase concentration than the other tissues. Looking into the role of this enzyme in the differentiation of lymphoid cells and maturation of monocytes to macrophages and taking note of the lack of sufficient information regarding the levels of biochemical parameters in tubercular and HIV subjects, the present study was initiated. Adenosine deaminase test can be used for early TB detection where TB is endemic or other diagnostic means are expensive in adult population. Adenosine deaminase analysis is a simple and inexpensive colorimetric test that can be performed on serum and body fluids. Since 1978, ADA it has been used in the diagnosis of tuberculous effusion by Puras,