Summary
The CAP released a guideline for amyloidosis lab workup, recommending Congo red staining for amyloid detection and mass spectrometry for fibril protein typing. The guideline emphasizes the importance of accurate and timely identification of amyloid fibril types for effective treatment.
Guideline on amyloidosis lab workup published
The CAP released in late November its guideline for proper testing and laboratory workup of amyloidosis, which includes four recommendations and three good practice statements.
The four conditional recommendations are as follows:
- In patients with suspected systemic amyloidosis, pathologists may screen cytology specimens (conventional smears and/or cell blocks) of aspirated abdominal fat for detection of amyloid. Note: Best preparation methods should be determined and optimized by individual laboratories, and ancillary testing techniques should be validated on cytologic material. Note: If cytologic smears only are prepared in the absence of a cell block, this limits the ability for further testing, including subtyping.
- When evaluating specimens for the presence of amyloid, pathologists should use the Congo red staining method. Note: Laboratories may use other methods but should validate against Congo red or electron microscopy and must show equivalency.
- When assessing Congo red histochemistry, pathologists may add fluorescence microscopy with the tetramethylrhodamine isothiocyanate (TRITC)/Texas red filter to increase sensitivity for amyloid detection, if available.
- In patients with amyloidosis being considered for therapy, to optimize diagnostic yield and tissue use, pathologists should use mass spectrometry to identify the fibril protein type. Note: In renal amyloidosis, amyloid fibril typing may often be successfully accomplished by immunofluorescence, although reflex to MS-based proteomics should be performed in difficult or equivocal cases.
The full guideline, including the good practice statements, is published online in Archives of Pathology & Laboratory Medicine (doi.org:10.5858/arpa.2025-0275-CP).
Amyloidosis is becoming a treatable disease, “but we have to identify the fibril type accurately and quickly,” said Billie S. Fyfe, MD, guideline expert panel co-chair, speaking last fall in a CAP25 session about the soon-to-be released guideline. “In addition,” she said, “clinicians are pushing us to identify amyloid at earlier and earlier time points. So they want us to have very sensitive methods and accurate classification of fibrils.”
Dr. Fyfe, of Rutgers Health Robert Wood Johnson Medical School, said if left untreated, 25 percent of patients with immunoglobulin light chain (AL) amyloidosis die within six months of diagnosis, and 25 percent of patients with amyloid transthyretin (ATTR) amyloidosis die within 24 months of diagnosis.
Dylan Miller, MD, of Intermountain Central Laboratory, co-chaired the guideline expert panel with Dr. Fyfe.
Gift to lab medicine students: $50 million over 50 years
UW Medicine in Seattle reported in early December a gift from an anonymous donor that will cover tuition for the senior-year clinical rotations of all undergraduate students enrolled in its Medical Laboratory Science program.
The gift will generate annual disbursements estimated to exceed $50 million over the next 50 years.
The undergraduate MLS program of the Department of Laboratory Medicine and Pathology at the University of Washington is a full-time, four-year course of study. Seventy students were in the program at the time of the gift announcement, and 35 had begun their senior-year clinical rotations. The gift to cover in-state tuition will help the program expand its enrollment to 100 students during the next 10 years, UW Medicine said.
Geoffrey S. Baird, MD, PhD, professor and department chair, said, “It has been a long-standing dream to provide more financial support to students during the professional phase of the UW-MLS program.”
Molecular point-of-care test for Bordetella cleared with CLIA waiver
Roche’s first point-of-care test for the detection of Bordetella infections, including pertussis, has been granted Food and Drug Administration 510(k) clearance and CLIA waiver. The PCR test uses the Cobas Liat system to deliver results in 15 minutes at the point of care.
The test not only detects Bordetella infections but also differentiates between three key species: B. pertussis; B. parapertussis; and B. holmesii, an emerging pathogen increasingly associated with pertussis-like symptoms and potential diagnostic challenges.
Roche tests approved to ID HER2-positive metastatic breast cancer patients eligible for Enhertu
The Food and Drug Administration approved additional indications for the Roche Pathway anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody and Ventana HER2 Dual ISH DNA Probe Cocktail tests. These tests are now approved to aid in identifying HER2-positive metastatic breast cancer patients who may be eligible for treatment with Enhertu (trastuzumab deruxtecan).
Until now, Roche’s Pathway HER2 (4B5) test had been approved for identifying metastatic breast cancer patients with HER2-low and HER2-ultralow expression. With this expanded approval, Roche’s 4B5 test in combination with the Ventana HER2 Dual ISH DNA Probe Cocktail can now be used to identify patients across the full spectrum of HER2 expression for potential eligibility for Enhertu.