Clinical Chemistry 56:10 1645–1651 (2010)
What Is Your Guess?
An Unlikely Pregnancy Dina N. Greene,1 Brian J. Hall,1 and David G. Grenache1*
CASE DESCRIPTION A 46-year-old woman presented for anterior cervical discectomy and fusion of C5/C6 and C6/C7 vertebrae to treat a cervical myelopathy. She had a history of anxiety disorders, epilepsy, and mild intellectual impairment. She denied any recent sexual activity, but was 2 weeks late for her menstrual cycle. A serum point-of-care human chorionic gonadotropin (hCG) test was interpreted as positive but a urine point-of-care hCG test was interpreted as negative and a quantitative serum hCG was ⬍2 IU/L (reference interval 0 –5 IU/L).
QUESTIONS 1. What are potential causes of the discrepant hCG test results? 2. What tests can be done to investigate the discrepancy? 3. What should the physicians do about the discrepant results before proceeding with the surgery? The answers are below. ANSWERS There are multiple reasons for discrepant hCG results. False-negative/decreased results can be caused by the
1
University of Utah Health Sciences Center, Department of Pathology, Salt Lake City, UT. * Address correspondence to this author at: Department of Pathology, University of Utah School of Medicine, ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT 84108. Fax 801-584-5207; e-mail
[email protected]. DOI: 10.1373/clinchem.2010.153064
high-dose hook effect (1 ) or high concentrations of specific hCG variants (2 ), whereas false-positive/increased results can be due to hCG-secreting malignancies (3 ) or pituitary hCG (4 ). Interfering antibodies have been implicated in both falsely increased and falsely decreased results (5 ). Investigations to identify the cause will vary depending on the pattern of test results. For example, to investigate a possible high-dose hook effect, sample dilution would be most appropriate. In this case, a positive serum qualitative result in 1645
What Is Your Guess? conjunction with a serum quantitative result below the measuring range of the assay suggested the presence of an interfering antibody. Consistent with this hypothesis, the qualitative test result was negative after treatment of the sample with a lyophilized interfering- antibody– blocking reagent. This case demonstrates that point-of-care hCG tests can produce erroneous results due to interfering antibodies. Physicians are encouraged to contact the laboratory when discrepancies occur or when test results are not consistent with the clinical evidence.
Author Contributions: All authors confirmed they have contributed to the intellectual content of this paper and have met the following 3 requirements: (a) significant contributions to the conception and design, acquisition of data, or analysis and interpretation of data; (b) drafting or revising the article for intellectual content; and (c) final approval of the published article.
Authors’ Disclosures of Potential Conflicts of Interest: No authors declared any potential conflicts of interest. Role of Sponsor: The funding organizations played no role in the design of study, choice of enrolled patients, review and interpretation of data, or preparation or approval of manuscript.
References 1. Stickle DF, Gronowski AM, Olsen GA, Fellows PA, Avery MB, Studts DJ, Pirruccello SJ. Decreased signal intensity of Sure-Vue serum/urine qualitative hCG test at high [hCG] [Abstract]. Clin Chem 2000;46(Suppl 6):A3. 2. Gronowski AM, Cervinski M, Stenman UH, Woodworth A, Ashby L, Scott MG. False-negative results in point-of-care qualitative human chorionic gonadotropin (hCG) devices due to excess hCGbeta core fragment. Clin Chem 2009;55:1389 –94. 3. Stenman UH, Alfthan H, Hotakainen K. Human chorionic gonadotropin in cancer. Clin Biochem 2004;37:549 – 61. 4. Snyder JA, Haymond S, Parvin CA, Gronowski AM, Grenache DG. Diagnostic considerations in the measurement of human chorionic gonadotropin in aging women. Clin Chem 2005;51:1830 –5. 5. Kricka LJ. Human anti-animal antibody interferences in immunological assays. Clin Chem 1999;45:942–56.
News & Views
Cyberintrusion—Happening Much Closer to You Than You Might Think! Hoi-Ying Elsie Yu1*
According to the Internet Crime Complaint Center (IC3)2 (www.ic3.gov), cybercrimes are rising rapidly. In 2009, 336 655 cybercrime complaints were submitted to IC3, a 22.3% increase compared with 2008. Of these complaints, 146 663 were referred to law-enforcement agencies for further investigation. These referred cases represented a combined financial loss of $559.7 million. Although many may think these crimes were the results of careless individuals who fell for those “you just inherited a million dollars” scams, the reality is that if you have Internet connection, hackers have probably already attempted to attack the information stored in your computer. According to a report by Perkel (1 ), an average of 27 000
1
Children’s Hospital Boston, Boston, MA. * Address correspondence to the author at: Children’s Hospital Boston, 300 Longwood Ave., BA 761, Boston, MA 02115. Fax 617-730-0383; e-mail elsie.
[email protected]. Received June 10, 2010; accepted June 14, 2010. 2 Nonstandard abbreviations: IC3, Internet Crime Complaint Center; IT, information technology.
1646 Clinical Chemistry 56:10 (2010)
hacking attempts were made per day during the first quarter of 2010 at the San Diego Supercomputer Center of the University of California. The report also provides some practical tips to enhance cybersecurity. Despite the alarming number of incidents, hacking attempts can usually be blocked successfully by well-coded firewalls. Most computer hackers look for open access or a poorly coded firewall to steal or sabotage data and intellectual property. Therefore, information technology (IT) professionals should be hired to write protective firewalls. Sensitive data should be managed by a centralized IT team that can monitor traffic and limit access. E-mail should be encrypted when sending sensitive data. Computers should be password-protected and encrypted. These measures may seem quite straightforward, but many academic researchers do not endorse them because of limited funding to hire IT professionals and the inconvenience that comes with heightened security. For example, cybersecurity means that personal computers should not be allowed to handle sensitive
