Starting November 29th, 2022, Corewell Health West, Hematology Laboratories will begin reporting absolute counts for white blood cell (WBC) manual differentials, in addition to relative (percentage) counts. The WBC differential count determines the number of each type of white blood cell present in the blood. It can be expressed as a percentage or as an absolute value. Of these, the absolute value is much more important than the relative value, given that clinically relevant WBC elevations and declines are defined by their absolute numbers, not by their relative proportions, and there is potential for error if this conversion is performed outside the laboratory.
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Obstetrics & Gynecology
Effective November 21, 2022, the following changes will be made to Meconium Drug Testing (LAB479).
- The cutoff for positivity for the opiate drug class (codeine, morphine, hydrocodone, hydromorphone, oxycodone, and oxymorphone) will increase to 20 ng/g from 10 ng/g.
- The format of reporting will be updated to include discrete reporting fields for all tested analytes. Positive results will no longer be denoted via comments.
Compliance & Safety, Education & Training, Microbiology
Update: Swabs for Cultures without a Source and Order
Effective May 9th, 2022, Spectrum Health Laboratory’s Microbiology Department will no longer be preemptively setting up cultures on swabs without a source and order, when received on Thursdays through Sundays and Holidays. Note: The specimen will still be held, but cultures will not be set up in anticipation of the order.
Advanced Technology Laboratory, Cytogenetics
Discontinuation of Low-Volume and Individual Fluorescence in situ Hybridization (FISH) Probes
Effective immediately, due to low test utilization and the high cost of maintaining proficiency, the following FISH tests will no longer be offered:
• Prader-Willi/Angelman (15q11-q13) by FISH
Recommended test is Angelman/Prader-Willi mPCR
• Smith Magenis (17p11) by FISH
If need arises for this test, please place an order for a Send out Genetics Miscellaneous and enter requested test in the comments. The testing will be sent out through Spectrum Health.
Any questions about referral testing may be directed to the Referral Department. Any questions or concerns regarding these changes may be directed to Dr. Salah Ebrahim in the Cytogenetics Laboratory.
General Information, Microbiology, Test Utilization
Discontinuation of Placenta Microbiology Cultures
As of April 12, 2022, Spectrum Health Laboratory will no longer add microbiology cultures to placental tissues received based on paper requisition forms.
Viral and bacterial cultures from placental tissue are rarely clinically beneficial and are no longer the gold standard diagnostic approach due to the relative insensitivity of culture methods.
If viral studies are desired (possible indications could include known CMV exposure with positive IgM or intrauterine fetal demise at < 28 weeks), then molecular testing is the recommended diagnostic approach. HSV and CMV PCR tests may be ordered in Epic.
• Herpes Simplex 1/2 Qualitative PCR, Tissue (LAB1230413)
• Cytomegalovirus (CMV) Qualitative PCR, Tissue (LAB1230291)
Bacterial cultures are challenging to interpret since they typically grow normal genital flora and histopathological analysis used to diagnose acute chorioamnionitis correlates poorly with growth from bacterial placenta cultures. If indicated, culture and PCR tests may be ordered in Epic.
• Metamycoplasma hominis, Molecular Detection, PCR, Varies (LAB848)
• Ureaplasma species, Molecular Detection, PCR, Varies (LAB848)
Placenta tissues sent to the lab in formalin are not acceptable for PCR or culture orders.
MTHFR C677T [LAB7390], the methylenetetrahydrofolate reductase mutation analysis, is being discontinued as an obsolete test.
The American College of Medical Genetics (ACMG) and American College of Obstetricians and Gynecologists (ACOG) have determined that MTHFR C677T testing has minimal clinical utility. Current testing recommendations indicate that this test should not be ordered as part of a routine evaluation for thrombophilia or adverse pregnancy outcomes.
On January 24th, 2022 Rubella Antibody, IgG, Serum (LAB496) and Rubella IgG Antibody Quantitative (LAB3544) will be combined as LAB496 and moved to the Immunochemistry laboratory due to reagent constrains with the current vendor.
Testing will be available Monday-Friday with a turn-around-time of 1-3 days. Results will be reported qualitatively as Immune or Not Immune. If quantitative results are needed, please fax Immunochemistry at 616-267-2771 or call 616-267-2770.
Effective February 1, 2022, the Cystic Fibrosis (CF) Carrier Screen test, which includes the 23 common variants for cystic fibrosis recommended by ACOG/ACMG, will be discontinued as an orderable test at Spectrum Health Laboratory.
The recommended replacement test is the Cystic Fibrosis Mutation Analysis (Test ID: CFP) offered by Mayo Clinic Laboratories, a 106-variant panel which includes the recommended 23 common variants.
The mitigation strategies enacted during the COVID-19 pandemic to reduce the spread of this virus led to essentially non-existent influenza prevalence during the 2020-2021 winter season. However, influenza has now returned and case numbers are increasing throughout West Michigan.
Influenza prevalence guides the most appropriate testing approach and sufficient prevalence has now been reached for influenza rapid antigen testing (e.g. Sofia instrument) to have improved performance. The use of rapid antigen testing as a screening method during high prevalence reduces both the cost to the patient and turn-around-time as compared to lab-based molecular methods. Rapid antigen tests generally have high analytical specificity, but lack the sensitivity of nucleic acid amplification methods (e.g. PCR). For this reason, PCR testing is still recommended for hospitalized patients and for outpatients with a negative antigen result if influenza is still suspected and if the result will impact clinical decision making.