A method for the determination of the percentage of CD4 T cells and CD4/CD8 ratio

DESCRIPTION provided by applicant The long term goal of the proposed research is to develop a simple quantitative point of care POC method for determination of percentage of circulating CD T lymphocytes and CD CD ratio in blood of pediatric patients CD cell counts are needed to stage and monitor HIV infected patients In adults the absolute number of CD T cells per microlitre of blood has critical prognostic and therapeutic implications and is used for both HIV staging and treatment decisions In pediatric patients the high variability of absolute CD T cell numbers occurs within first or years of age In addition concurrent illnesses may affect CD counts Therefore in pediatric patients aged less than or years it is strongly recommended that percentage of CD T cell measurement within the lymphocyte populations CD ly is determined since this parameter CD ly is far less variable than the absolute CD T cell counts The gold standard technique currently used for quantitation of CD cells and determination of CD ly is flow cytometry However flow cytometers including smaller single purpose CD cell counting devices are expensive and are generally inaccessible in resource limited countries Because flow cytometry based CD cell counting is beyond the reach of so many HIV infected people the World Health Organization WHO has urged the development of simple point of care CD cell count and CD ly assays designed for resource limited settings Recently a number of manual assays have emerged to meet specific demands for rapid testing of CD cell count in blood However significant limitations of these assays such as multi step operating procedures use of relatively expensive equipment and slow sample turnover hinder their widespread use Moreover to our knowledge currently there are no manual methods on the market that provide CD ly measurements It is in this context that we propose to develop a quantitative fast and inexpensive assay for determination of percentage of CD T cells in less than years old children The proposed method flow through cell counting assay FTCA is based on the use of the special membrane and a proprietary flow through cassette to measure cell count status The test can potentially be completed in less than minutes and can be performed by laboratory technicians with low levels of training The specific aims of Phase I are Development of an a prototype of the disposable FTCA cartridge for simultaneous detection of CD CD T cells and total lymphocytes Examine and select the most suitable antibodies and filters for determination of CD CD counts and total lymphocytes by FTCA Explore all variables affecting the performance of the FTCA and optimize the conditions of the assay Compare the analytical performance of CD ly and CD CD determination by the FTCA and conventional flow cytometry assay using a limited number of well characterized clinical samples Advantages of the proposed technology such as the speed convenience and low cost of the analysis substantiates our belief that the FTCA will be widely used in clinical practice PUBLIC HEALTH RELEVANCE The development of the proposed method will allow using tests for determination of percentage of circulating CD T lymphocytes and CD CD ratio in blood of pediatric patients for staging and monitoring HIV infection in children Successful completion of these studies will be beneficial for public health and make available all of the technology needed for a substantial business opportunity to license the technology and manufacture commercial products