DNA, drug abuse and mistaken identities

Several drug-related stories shocked us this month. On July 3, a 35-year-old Filipina was executed by the Chinese government for drug trafficking. She was the fifth Filipino since 2011 to be legally murdered by an independent state for transporting drugs. Ten days later, 31-year-old Cory Monteith, the promising and multi-talented Canadian actor and Glee star, died because of heroin overdose combined with alcohol consumption.

Globally, the number of drug users and drug-related crimes has reached phenomenal proportions. The 2012 World Drugs Report released by the United Nations Office on Drugs and Crime (UNODC) indicated that over 230 million people used illicit drugs in 2010 alone. This is roughly one in 20 persons. In the Philippines, about 1.7 million people are addicted to drugs, resulting in about 1,700 casualties annually (http://www.philstar.com/ headlines/2012/11/14/866389/ddb-17-million-pinoys-hooked-drugs).

Given these shocking news and bothering statistics, one cannot help but reflect on the problems and dangers brought about by the use of illicit drugs in our country and in the world. Governments across the globe are and have been in active and intensive campaign against trafficking and the use of dangerous drugs.

In the Philippines, mandatory drug testing is imposed on applicants for firearms license, members of law enforcement agencies and persons who are candidates for public office. Random drug testing is implemented on officers and employees of public and private offices, and students of tertiary and secondary schools. In sports, random and target doping control tests are implemented to detect use of performance-enhancing drugs among athletes. If a person’s urine sample tested positive for illegal drug precursors and subsequently he/she is proven guilty of use, corresponding legal responsibilities would be imposed on the person. Reprimands imposed by the law may either be rehabilitation, imprisonment or penalty depending on the extent of drug use.

In some situations where prohibited substances are detected in urine samples, the identity of the human source of the sample may be questioned. And every so often we hear a person claiming that he/she is not guilty of drug use. Instead, allegations of switching of urine samples and mistaken identities are made. Claims like this may be true and valid, or may also be attempts to escape punishment. Considering the severity of penalties of drug use, it is imperative that the identities of samples remain unquestioned.

Confirmation of the identity of a sample used for drug testing may be made with the aid of DNA analysis. In the US and elsewhere, DNA profiling of urine samples is used to resolve the issue of the human sources of these samples in some drug cases. In contrast, the Philippines has yet to adopt a system to resolve issues of identification associated with drug testing.

Urine is the most common sample that is submitted for drug testing. The existence of DNA in urine is well investigated, with epithelial cells being the primary source of DNA for this type of sample. Hence, DNA analysis of urine samples can be used to solve questions on sample identity. However, a urine specimen is considered one of the most challenging samples for DNA typing particularly when handling samples from males. Urine from females contains more epithelial cells and has a higher rate of obtaining positive DNA results. Since more male urine samples are submitted for drug testing, there is an urgent need to validate more sensitive DNA procedures to increase the likelihood of successful DNA typing of urine samples from male as well as female sources.

The DNA Analysis Laboratory, Natural Sciences Research Institute (UP-NSRI DAL; www.dnaforensic.org) received funding from the Office of the Vice Chancellor for Research and Development of the University of the Philippines (http://ovcrd.upd.edu.ph/) to validate procedures for DNA profiling of urine samples. The ongoing research also proposes to address the procedures used for routine storage of urine samples. Since urine samples are the primary evidence in investigations involving drug use, these samples should be handled properly in order to preserve the DNA. Current practices in the handling of urine samples that tested positive for drugs include cold storage at -20°C for 15 days to one year. During this period, affected parties may request the re-testing of samples for the presence of drugs, especially when there are allegations of sample switching or errors in the conduct of the actual drug tests.

DNA profiling of urine samples is expected to confirm or negate the issue of sample switching. To determine the effect of temperature on the success of DNA recovery, samples provided by volunteers had been stored at different conditions simulating storage and handling conditions in drug testing laboratories. Samples will be extracted at different intervals to determine the success of DNA recovery over time. This research is ongoing until the end of 2013. To our knowledge, this is the first study in the Philippines, which proposes to use DNA in order to simplify the investigations into allegations of erroneous identification or misidentification in drug investigations. By providing a tool to protect the identity of sources of urine samples and the integrity of the drug testing scheme, the research team at UP-NSRI DAL hopes to aid in the Philippines’ effort to reduce the use and trafficking of illicit drugs within and across our national borders.

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Maria Lourdes D. Honrado was a City of Mandaluyong Collegiate Scholarship (CMCS) BS Biology graduate Major in Biotechnology from Rizal Technological University. She joined the DNA Analysis Laboratory, Natural Sciences Research Institute in 2011. She is the principal investigator of the project entitled “DNA Profiling of Human Urine Samples for Identification” funded by the Office of the Vice Chancellor for Research and Development, University of the Philippines, Diliman while being enrolled in the Masters qualifying program of the Institute of Biology, University of the Philippines, Diliman (http://biology.upd.edu.ph/).

Dr. Maria Corazon A. de Ungria is the head of the DNA Analysis Laboratory, Natural Sciences Research Institute of UP Diliman (http://nsri.upd.edu.ph/nsri/). The UP-NSRI DNA Laboratory (www.dnaforensic.org) offers its DNA profiling, biobanking and parentage testing expertise as part of its advocacy of maximizing the use of science, particularly DNA technology, to answer social and legal questions that affect society. The laboratory may be contacted at 632 925-2965 and [email protected].