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Laboratory evaluation for the presence of antineutrophil cytoplasmic antibodies (ANCAs) is used diagnostically in the evaluation of patients suspected of having systemic vasculitis. (1-4) The main utility in ANCA testing [...], Context.--Variability in testing for antineutrophil cytoplasmic antibodies (ANCAs) contributes to confusion and controversy related to testing for vasculitis and other ANCA-associated diseases. Objectives.--To survey laboratory testing practices regarding ANCA testing and to investigate differences in testing algorithms. Design.--Supplemental questions were sent to the 333 laboratories participating in the College of American Pathologists proficiency testing program for ANCA as part of the Special Immunology S2 Survey. Results.--A total of 315 laboratories submitted responses to the supplemental questions. Only 88 of 315 participants (28%) reported using a combination of indirect immunofluorescence (IFA) and enzyme immunoassay (EIA) techniques as recommended by current guidelines, with a few additional labs using IFA and multiplex bead assay as an acceptable alternative to EIA. Other labs reported using only IFA, EIA, or multiplex bead assays. Conclusions.--A wide variety of testing algorithms are in use for ANCA testing despite evidence to suggest that a combination of IFA and EIA testing provides the most comprehensive information. Laboratories should inform clinicians clearly about testing practices and utility of testing in specific disease states. (Arch Pathol Lab Med. 2016; 140:524-528; doi: 10.5858/arpa.2015-0221-CP)

Although multicolor flow cytometry was originally introduced into the field of diagnostic hematopathology as an ancillary or companion diagnostic test, this powerful tool is becoming a primary diagnostic modality, independent [...], Context.--Flow cytometry is often applied to minimal residual disease (mRd) testing in hematolymphoid neoplasia. Because flow-based MRD tests are developed in the laboratory, testing methodologies and lower levels of detection (LODs) are laboratory dependent. Objectives.--To broadly survey flow cytometry laboratories about MRD testing in laboratories, if performed, including indications and reported LODs. Design.--Voluntary supplemental questions were sent to the 549 laboratories participating in the College of American Pathologists (CAP) FL3-A Survey (Flow Cytometry--Immunophenotypic Characterization of Leukemia/ Lymphoma) in the spring of 2014. Results.--A total of 500 laboratories (91%) responded to the supplemental questions as part of the FL3-A Survey by April 2014; of those 500 laboratories, 167 (33%) currently perform MRD for lymphoblastic leukemia, 118 (24%) for myeloid leukemia, 99 (20%) for chronic lymphocytic leukemia, and 91 (18%) for plasma cell myeloma. Other indications include non-Hodgkin lymphoma, hairy cell leukemia, neuroblastoma, and myelodysplastic syndrome. Most responding laboratories that perform MRD for lymphoblastic leukemia reported an LOD of 0.01%. For myeloid leukemia, chronic lymphocytic leukemia, and plasma cell myeloma, most laboratories indicated an LOD of 0.1%. Less than 3% (15 of 500) of laboratories reported LODs of 0.001% for one or more MRD assays performed. Conclusions.--There is major heterogeneity in the reported LODs of MRD testing performed by laboratories subscribing to the CAP FL3-A Survey. To address that heterogeneity, changes to the Flow Cytometry Checklist for the CAP Laboratory Accreditation Program are suggested that will include new requirements that each laboratory (1) document how an MrD assay's LOD is measured, and (2) include the LOD or lower limit of enumeration for flow-based MRD assays in the final diagnostic report. (Arch Pathol Lab Med. 2015; 139:1276-1280; doi: 10.5858/arpa.2014-0543-CP)