Effective January 4, 2023, the process for reporting the Microalbumin/Creatinine ratio was changed for situations where one of the results, microalbumin and/or creatinine, is below or above the assay’s analytical measuring range (AMR).
Albumin Reagent Conversion
Corewell Health Laboratories (formerly Spectrum Health) has utilized the Bromcresol Purple (BCP) method for the measurement of albumin concentration in serum, plasma, and serous body fluids for well over 20 years. The test principle consists of a reaction where the BCP binds selectively with albumin, causing a color change that is measured photometrically. A vast majority of labs across the country, including reference labs such as Mayo Medical Laboratories, utilize an alternative method for albumin measurement that consists of Bromcresol Green (BCG) instead of BCP. To align with the majority of institutions this size, and to be included in a larger peer group for proficiency testing purposes, Corewell Health Laboratories – West, has been transitioning to BCG for the measurement of albumin over the last few weeks.
Corewell Health Laboratory (Grand Rapids) Coagulation laboratory is pleased to announce a change to our von Willebrand factor (VWF) activity test. The historical test von Willebrand ristocetin cofactor (LAB335) will be retired and replaced by von Willebrand factor activity (VWF activity, LAB1230904) on January 17, 2023.
Respiratory syncytial virus (RSV) primarily infects pediatric patients, but occasionally infects adults and may be of particular concern for the elderly and immunocompromised. Corewell Health Laboratories offers two tests for RSV. A rapid antigen test may be used to confirm RSV diagnosis in pediatric patients. This test is not approved by the FDA for testing adult patients, so tests will be cancelled if ordered on an off-label age group. There are no age restrictions for RSV testing by way of a molecular panel that also includes COVID and influenza as viruses with overlapping symptoms.
| Test name | Epic Test ID | Methodology | Specimen | Age restriction |
| RSV Rapid | LAB495 | Antigen | Nasopharyngeal (NP) swab | Approved for patients 0 – 18 years of age |
| COVID, Influenza, RSV PCR | LAB1230746 | Molecular/PCR | Nasopharyngeal (NP) swab | No age restriction |
The following information was updated in the Lab Catalog.
Influenza cases numbers are currently 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.
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.