IDH1/IDH2 Mutation Analysis by PCR and Pyrosequencing

University of Virginia Health System Medical Laboratories “Quality You Expect, Service You Deserve”

LABORATORY MEDICINE UPDATE

October 1, 2012

IDH1/IDH2 Mutation Analysis by PCR and PyroSequencing

The Molecular Diagnostics Laboratory is now offering analysis to detect common, clinically significant point mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2). IDH1 and IDH2 are key enzymes in the mitochondrial citric acid cycle. Somatic mutations in codon 132 of IDH1 and codon 172 in IDH2 have been described in a significant proportion of patients with anaplastic astrocytomas and secondary glioblastomas. This assay targets these codons in IDH1 and IDH2. It will not detect mutations in other regions of either gene. Overall frequency of these mutations is in the range of 60-90% in these tumors. These mutations are rarely found in primary adult or pediatric glioblastomas.

In patients with glioblastomas or anaplastic astrocytomas, the presence of an IDH1 or IDH2 mutation is associated with a significantly longer overall survival. Multiple factors contribute to prognosis in these patients and the results of this assay are but one of them. Thus, this assay is intended for use as an aid in developing patient specific prognostic predictions.

The IDH1 and IDH2 mutations are also found in about15- 20% of acute myeloid leukemias and at a much lower frequency in myelodysplastic and myeloprolferative disorders (2-5%).

Methodology: PCR of each codon followed by pyrosequencing on the Qiagen PyroMark Q24 system.

Required specimen: formalin fixed paraffin embedded tumor tissue. A matched H&E with the area of interest circled must accompany each sample. Determination of percent tumor load is also required. Ideally at least 40 to 50% of the sample should contain tumor material.

Bone Marrow Slide Labeling

Bone Marrow aspirate / biopsy / touch prep slides made at the patient bedside are critical in assessing hematologic neoplasms. In keeping with The Joint Commission National Patient Safety Goals on patient identification and in conjunction with the College of American Pathologist accreditation regulations, all slides must be labeled at the bedside with proper identification. Preferably the patient name and medical record number should be written on the slide however with limited space, just the name is acceptable per laboratory standards. Placing unlabeled slides in a container and labeling the outside of the container is not appropriate. A Bone Marrow procedure checklist is available from the Cancer Center Laboratory at 924-9071.

of 2 Gram Stain from Genital Cultures discontinued

In accordance with current guidelines, the Clinical Microbiology laboratory will discontinue performance of gram stain smears on specimens received for genital culture. Gram stains will continue to be performed in conjunction with culture for Neisseria gonorrhoeae upon request, only when the specimen source is a male urethral swab. A separate order for Gram stain for N. gonorrhoeae is required. Due to issues with reduced specificity, Gram stains for N. gonorrhoeae are not recommended for female genital specimens.

If bacterial vaginosis or vaginitis is suspected, the Affirm test is available as a referral test, and collection devices can be obtained from the Clinical Laboratory (please refer to previous LMU notification below for additional information).

From LMU 8/14/12: New Referral Lab Test Microbial Vaginosis/Vaginitis Panel

Medical Laboratories is now offering a DNA probe test for detection and identification of Candida species, Gardnerella vaginalis and Trichomonas vaginalis nucleic acid in vaginal fluid specimens from patients with symptoms of vaginitis/vaginosis. Samples are accepted Monday through Friday, with results available in 2 to 3 days. The required collection kit (AFFIRMTM VPIII Ambient Temperature Transport System) is available by calling 434-924-5227. Samples submitted with any other collection device will be rejected.

Bacterial vaginosis (BV) is the most common vaginal infection, and accounts for up to 50% of vaginitis/vaginosis cases, depending upon the patient population. While G. vaginalis is no longer thought to be the only etiologic agent of BV, it is still considered to be a primary contributor to infection, which involves an increase in anaerobic bacteria and reduction in normal vaginal flora. BV is considered a risk factor for adverse pregnancy outcome and post-hysterectomy cuff cellulitis. BV-associated bacteria in the endometrium may be etiologic agents of endometritis and pelvic inflammatory disease, independent of Gonorrhoeae and Chlamydia infection. Vaginal candidiasis is the second most common form of vaginal infection seen. Approximately half of all adult females will have one or more episodes of vaginal candidiasis in their lifetime, with up to 5% suffering from recurrent and sometimes intractable yeast infection. Trichomoniasis, a non-reportable sexually transmitted disease, has been associated with adverse pregnancy outcomes, post-surgical gynecologic infections, and post-hysterectomy cuff cellulitis.

If you have questions or concerns, please contact the Microbiology Director at PIC 3677 or 924- 5667.

Insurance Denials for High-Sensitivity CRP (C-Reactive Protein) Testing

Medical Laboratories has received information from Palmetto GBA Medicare, the Health System’s fiscal intermediary for billing Medicare claims, that claims for High sensitivity C- reactive protein testing will not be covered. Their reasons include:  Current literature does not support the use of high sensitivity CRP for diagnostic purposes  Medicare does not cover high sensitivity CRP testing for screening, prevention or risk stratification of cardiovascular disease

However, Standard sensitivity CRP is covered as a diagnostic test for the detection and evaluation of infection, tissue injury and inflammatory disease.