Comparative evaluation of three JAK2V617F mutation detection methods.

The correlation of JAK2V617F with a proportion of chronic myeloproliferative disorders has generated numerous studies focused on the development of molecular-based assays for JAK2V617F detection. The current parallel study comparatively evaluated 3 JAK2V617F molecular detection methods. Genomic DNA from blood or bone marrow was assayed by 3 laboratories using allele-specific polymerase chain reaction (AS-PCR) or kit-based restriction fragment length polymorphism methods, which used polyacrylamide gel or capillary electrophoresis analysis. In addition, samples were sequenced in 2 of the laboratories. Results found 100% concordance among the 3 methods, with analytic sensitivities of 5% for both kit methods and 0.01% for AS-PCR. The kitbased assays detect JAK2V617F with equal sensitivity regardless of analysis method, and, despite greater sensitivity of AS-PCR, all 3 methods yielded 100% concordant results for this 36-sample set. Consistent with other reports, direct sequencing was insufficiently sensitive to serve as an initial diagnostic tool for JAK2V617F detection.

Human papillomavirus testing methods.

Testing for human papillomavirus (HPV) relies exclusively on techniques of molecular biology using nucleic acid probes. Tests for HPV using nucleic acid probes have been commercially available since the late 1980s, but early tests were cumbersome, involving the use of nucleic acid probes labeled with radioactive phosphorus (32P). These early HPV tests did not achieve widespread use because they did not detect all oncogenic HPV genotypes. The current commercial HPV detection kit, Digene's Hybrid Capture 2 kit, detects virtually all high-risk oncogenic HPV types, as well as most low-risk nononcogenic HPV genotypes. The Hybrid Capture 2 test format is a proprietary nucleic acid hybridization signal amplification system owned by Digene Corporation. Virtually all test formats for DNA sequence analysis are amenable to applications intended to detect and perhaps quantify the various HPV genotypes. These methods can involve direct hybridization with complementary DNA probes, such as Southern blotting or in situ hybridization, signal amplification, such as the Hybrid Capture 2 method or target nucleic acid amplification, most notably the polymerase chain reaction (PCR). Polymerase chain reaction has been used for HPV detection, genotyping, and viral load determination. General or consensus primer-mediated PCR assays have enabled screening for a broad spectrum of HPV types in clinical specimens using a single PCR reaction. Following amplification using consensus primers, individual HPV genotypes are identified using a variety of methods. Using consensus primers in a test format known as real-time quantitative PCR (RQ-PCR), it is possible to generate viral load (concentration) data from reaction curves generated by monitoring PCR reaction kinetics in real time.

Achieving quality reproducible results and maintaining compliance in molecular diagnostic testing of human papillomavirus.

Laboratories contemplating either the addition of new molecular tests or modifying methods approved by the Food and Drug Administration for human papillomavirus testing should be aware of a variety of procedural, performance, and regulatory issues surrounding such activity. Diagnostic medical laboratory testing in the United States is regulated by the Centers for Medicare and Medicaid Services, an agency formerly known as the Health Care Finance Administration. The regulatory vehicle of the Centers for Medicare and Medicaid Services is manifested in the Clinical Laboratory Improvement Amendments (CLIA). The CLIA program has put into place specific regulations for laboratory quality control, which includes specific recommendations for method validation. Regulations that must be followed regarding personnel, quality control, quality assurance, method validation, and proficiency testing depend on the complexity category of the individual test. All molecular diagnostic tests, including those for human papillomavirus, are considered high complexity. The Centers for Medicare and Medicaid Services retains the authority to allow private, national accreditation organizations to "deem" that a laboratory is compliant with CLIA '88 requirements. Accreditation organizations, such as the Joint Commission for Accreditation of Hospitals, the Commission on Office Laboratory Accreditation, and the College of American Pathologists (CAP), as well as several state medical laboratory-accrediting agencies, possess the authority to deem laboratories as "CLIA-approved." The CAP, through its Laboratory Accreditation Program, has promoted standards for laboratory performance and method validation. In general, guidelines set forth in the CAP Laboratory Accreditation Program checklists specify that all clinical laboratory testing must essentially meet those requirements defined for high-complexity testing under CLIA '88, including test validation standards, reportable/reference ranges, performance criteria, and proficiency testing.