Molecular Pathology

Molecular Pathology

The revolutionary advances made in molecular biology during the past quarter century have made a major impact on clinical laboratory diagnosis. This is evident from rapid acceptance and adoption of molecular diagnostics in laboratories around the world. Generally, emphasis is now for the acquisition of latest DNA technology to provide timely and high quality services to patients. Moreover, molecular biology offers novel strategies for gene therapy protocols, which have potential for use in future to correct genetic defects and treat cancer.

The Section of Molecular Pathology was established in 1995 and provides testing and expertise for interpretation of molecular diagnostics as well as support for investigational research. The scope of our molecular pathology testing includes infectious diseases, oncology, molecular genetics and histocompatibility analysis. A variety of both qualitative and quantitative virology tests are offered, and they are based on viral nucleic acid detection using polymerase chain reaction and oligonucleotide probe hybridisation. Hepatitis viruses (B, C and D types), Herpes Simplex virus, Cytomegalovirus, Human papillomavirus, Epstein Barr virus and Cremeon Congo hemorrhagic fever virus represent the major viral types analysed in the Molecular Pathology Laboratory. These tests help clinicians identify the correct diagnosis of Hepatitis C and monitoring of its treatment. RNA based genotyping of Hepatitis C is added to this list to help clinicians in making correct therapeutic decisions. DNA technology has provided powerful tools for genetic diagnosis, especially of single gene disorders such as thalassemia, cystic fibrosis, congenital adrenal hyperplasia and others. Presently, the Molecular Pathology Laboratory offers prenatal diagnosis for ß-thalassemia, and, to date, more than 450 tests have been successfully performed. In addition, ?F508 mutation screening is also available for prenatal diagnosis. Human Leukocyte Antigen (HLA) matching is an important criterion for organ transplant. The Molecular Pathology Laboratory provides low to intermediate resolution nucleic acid based typing facility for HLA class I and II loci. HLA-A, -B, -C, -DR, -DQ alleles are typed using PCR-SSP technology obtained from leading manufacturers. For post transplant monitoring quantification of donor chimerism is also included in the repertoire. The vision of the Molecular Pathology Laboratory is to make available the latest and high quality DNA diagnostics to improve health.

Presently, there is no structured residency programme in the Section; however, residents from Histopathology, Microbiology, Chemical Pathology and Haematology sections rotate in Molecular Pathology as a part of their comprehensive training programme. Residents acquire special knowledge of molecular pathology on issues related to the application of DNA/RNA technology in wide variety of clinical circumstances. For example, in infectious diseases, they learn molecular diagnosis of several of the common viral and bacterial agents prevalent in Pakistan. Residents also learn how to correlate clinical findings and other laboratory tests with molecular diagnostic reports.

In addition, through the Elective Rotation Programme, AKU students and visiting medical students are taught the latest molecular techniques and their applications in infectious diseases cancer and genetic disorders. The Section also participates in the Technologist Training Programme of the clinical laboratory which includes two months of formal teaching and laboratory skills training in molecular pathology. Trainees are provided knowledge and skills of several molecular diagnostic techniques, results interpretation and different aspects of quality assurance.

The research activities of the Section include several areas of investigation. These activates are supported by both internal and external peer-reviewed grants received by the faculty.

One major theme of research is the study of Immunopathology of mycobacterial infections and the role of chemokine activation in the outcome of tuberculosis in pulmonary and extra-pulmonary infections. The intended goals of these projects are to understand the molecular and cellular basis of the difference between immune responses in localised and extrapulmonary tuberculosis. Another area of research interest of our faculty is to investigate molecular epidemiology of M. tuberculosis strains, to enhance our understanding of prevalence and transmission patterns of tuberculosis in Pakistan using spacer-oligotyping and IS6110 RFLP typing techniques.

The second area concerns identification of mutations in BRCA1 gene in breast cancer patients with family history. In our population, contribution of hereditary breast cancer equals to 15 to 20 per cent of the total cases. A plausible reason for this observation may be the fact that marriages within ethnic groups and especially between close relatives are very common in our population. Identification of BRCA1 mutations will help families' early detection of individuals at risk of breast cancer.​