Pathology · Haematology, point-of-care white cell and neutrophil count
Athelas Home
Athelas, Inc.
Athelas Home moves the white cell and neutrophil count that a patient at risk of neutropenia needs out of the laboratory and onto a kitchen table. Three FDA clearances since 2018 rest on manufacturer method comparisons, and the February 2026 clearance that opened point-of-care use added no new performance data. One peer-reviewed paper exists, and it measures satisfaction, not accuracy.
Performance Metrics
Clinical Evidence
The FDA record is one body of manufacturer data carried across three clearances. The K243348 decision summary refers every analytical performance section to the two earlier submissions. The original comparison (Athelas One, K181288) ran 312 patient samples from three US point-of-care sites against a Sysmex XE-5000 laboratory analyser. The FDA decision memorandum lists 113 fingerstick and 195 venous samples, four short of the 312 total. With all sites combined, WBC agreed at r 0.99 with slope 0.978 (95 per cent CI 0.958 to 1.000) and a mean bias of -0.151 x 10^3/µL (-2.31 per cent). NEUT% agreed at r 0.96 with slope 0.980 (0.953 to 1.003), intercept 1.855 (0.530 to 3.677) and a mean bias of 0.636 percentage points. Every pre-set criterion was reported as met. The same samples fed a flagging comparison against the XE-5000. For morphological flags, Athelas One flagged 90 of 99 abnormal samples and cleared 206 of 213 normal ones: sensitivity 90.9 per cent, specificity 96.7 per cent. For distributional flags (leukopenia and leukocytosis) it caught 34 of 39, a sensitivity of 87.2 per cent (95 per cent CI 72.6 to 95.7), with specificity of 98.5 per cent. A 59-patient matrix study found fingerstick and venous blood agreed on the same device (WBC r 0.996, slope 1.026; NEUT% r 0.969, slope 0.999). The home data (K200828) compare Athelas Home in patients' homes with Athelas One run by trained staff, not with a laboratory analyser. The two public documents give different figures for this study. The FDA decision summary describes 61 patients (with neutropenia, autoimmune disease, immunosuppressive cancer therapy or clozapine treatment) and 117 paired results. WBC ran from 1.3 to 14.4 x 10^3/µL, with r 0.97 and slope 1.00 (0.97 to 1.05). NEUT% ran from 21 to 78, with r 0.95, slope 1.00 (0.93 to 1.05) and a bias of 1.00 percentage point at both decision levels. The applicant's 510(k) summary instead reports 165 home samples: WBC r 0.97, slope 1.0 (0.95 to 1.03), mean bias 0; NEUT% r 0.92, slope 1.0 (0.98 to 1.09), intercept -1.0 (-6.09 to 0.0), mean bias -0.5 percentage points. Neither document explains the difference. No home sample fell below WBC 1.0 x 10^3/µL or NEUT% 21, so neither shows performance in severe neutropenia. For repeatability, 24 self-testing patients ran duplicate fingersticks within five minutes. The applicant reports a pooled WBC CV of 5.4 per cent against a 7.5 per cent criterion. The FDA precision profile splits it by level: 2.8 per cent at a mean of 2.5, 6.2 per cent at 6.1 and 7.6 per cent at 11.8 x 10^3/µL, the last just above the criterion. Ten patients testing control material at home reached a CV of 10.3 per cent on the low level. Of 81 home tests, 76 (94 per cent) ran without an error. In the supervised first visits, 22 of 32 tests were run by a caregiver rather than the patient. Peer-reviewed evidence is one paper. Kelly and colleagues (Annals of Clinical Psychiatry 2021) report a sub-analysis of a prospective, open-label clozapine trial in which patients gave a venous draw and an Athelas One fingerstick at baseline and week two and rated the two on a five-point scale. Patients reported convenience and value, there was a trend towards less concern about blood draws, and physicians preferred the point-of-care sample. The abstract gives no accuracy figures and no sample size, and one author lists an Athelas affiliation. No independent accuracy study of Athelas One or Athelas Home was found in PubMed. Independent evaluations of rival point-of-care counters for clozapine monitoring (Journal of Applied Laboratory Medicine 2023; Clinical Biochemistry 2025) did not include an Athelas device. The evidence grade is prospective because the peer-reviewed study is a sub-analysis of a prospective trial and the FDA comparisons collected fresh samples for the purpose; none of them tests accuracy against a clinical outcome, and there is no randomised trial. AurisMark reasoning: one FDA clearance and one peer-reviewed paper earn one mark. A second is withheld because the prospective evidence is agreement with the manufacturer's own analyser and a satisfaction survey, no independent accuracy study exists, no primary source documents deployment scale, and the only jurisdiction located is the United States.
| Study | Design | n | Sensitivity | Specificity | AUC | Published |
|---|---|---|---|---|---|---|
| Athelas, Inc. (Athelas One method comparison vs Sysmex XE-5000, FDA 510(k) K181288) | ProspectiveProspective | 312 | n/a (method-comparison endpoint) | n/a (method-comparison endpoint) | — | FDA 510(k) summary K181288, decision 5 November 2018; reprinted in K200828 and K243348. 312 patient samples at three US point-of-care sites, run in singlet on the XE-5000, covering the reportable range and medical decision levels. The FDA decision memorandum lists 113 fingerstick and 195 venous samples. Combined sites, Passing-Bablok: WBC (1.1–23.0 x 10^3/µL) r 0.99, slope 0.978 (0.958–1.000), intercept -0.042 (-0.159 to 0.086), mean bias -0.151 x 10^3/µL (-2.31%); NEUT% (8.0–92.89) r 0.96, slope 0.980 (0.953–1.003), intercept 1.855 (0.530–3.677), mean bias 0.636 percentage points (1.18%). All pre-set criteria reported as met. Analytical agreement study, not a clinical-outcome study. |
| Athelas, Inc. (abnormal-sample flagging comparison vs Sysmex XE-5000, FDA 510(k) K181288) | ProspectiveProspective | 312 | 90.91% morphological (90 of 99); 87.2% distributional (34 of 39) | 96.71% morphological (206 of 213); 98.5% distributional (269 of 273) | — | FDA 510(k) summary and decision memorandum K181288; same 312 samples. Morphological flags against the XE-5000 (predicate flag counts: abnormal lymphocytes or blasts 51, blasts 46, immature granulocytes 29, platelet clumps 15, left shift 14): overall agreement 94.87% against a 90% criterion modelled on the Sysmex XN flagging study design. Distributional flags (leukocytosis, leukopenia): positive agreement 87.2% (95% CI 72.57–95.70), negative agreement 98.5% (96.29–99.60), overall 97.12%. |
| Athelas, Inc. (at-home method comparison, Athelas Home vs Athelas One, FDA 510(k) K200828) | ProspectiveProspective | 117 | n/a (method-comparison endpoint) | n/a (method-comparison endpoint) | — | FDA decision summary K200828, decision 22 March 2022. 61 patients (neutropenia, autoimmune disease, immunosuppressive oncology therapy, clozapine), 1–4 visits each; a single self-test on Athelas Home against the mean of triplicates by trained operators on Athelas One; 15 strip lots. WBC (1.3–14.4 x 10^3/µL): r 0.97, slope 1.00 (95% CI 0.97–1.05), intercept 0.00 (-0.33 to 0.16). NEUT% (21–78): r 0.95, slope 1.00 (0.93–1.05), intercept 0.00 (-2.25 to 5.00); bias 1.00 percentage point at NEUT% 46.4 and 76.9. The applicant's 510(k) summary, reprinted in K243348, reports 165 samples instead: WBC (1.0–16.9) r 0.97, slope 1.0 (0.95–1.03); NEUT% r 0.92, slope 1.0 (0.98–1.09), intercept -1.0 (-6.09 to 0.0), mean bias -0.5 percentage points. The comparator is the manufacturer's own point-of-care analyser, not a laboratory instrument. |
| Kelly DL, Ponomareva OY, Mackowick M, Glassman M, Park J, Navarro-De La Vega M, Wehring HJ, Vyas G (University of Maryland; one author at Athelas) | ProspectiveProspective | 0 | — | — | — | Annals of Clinical Psychiatry 2021;33(2):116-123 (PMID 33878286). Sub-analysis of a prospective open-label clozapine trial: venous draw and Athelas One fingerstick at baseline and week 2, five-point Likert comparison. Reports patient-perceived benefit, a trend to less concern about blood draws, and greater physician satisfaction with point-of-care sampling. No accuracy data and no sample size in the abstract. |
Inside the algorithm
Editorial featureHow a fingerstick becomes a neutrophil percentage.
Five stages — from raw input to verdict — drawn from manufacturer documentation and the public regulatory record.
- INGEST
- NORMALISE
- DETECT
- LOCALISE
- VERDICT
Stage 01 · INGEST
One drop of blood on a pre-stained strip.
The patient lances a fingertip and touches 3.5 µL of blood to the inlet of a single-use Athelas test strip. In point-of-care use the operator can instead pipette capillary blood from a K3EDTA tube or venous blood from a K2EDTA tube. The strip has an upper and lower optical panel with a region coated in dry methylene blue and cresyl violet, so no liquid reagent is handled. Fill-volume testing showed that an empty strip returns an error and that 1.4 to 5.4 µL gave results within the bias criteria. The strip goes into the analyser, which is factory calibrated and runs an automatic calibration at the start of every test.
Input
Whole blood, one strip per test
Inference
Cloud, per test
Inside the Auris+ Listing
Five more sections complete this device’s Auris+ Listing.
Decision Ledger
ProPro unlocks a private, cross-vendor log of every case you read on this device — what the AI called, what you concluded, and a one-line reason if you overrode it. Ready for the EU AI Act's deployer logging obligations when they land in 2028.
Clinical Evidence Deep Dive
ProPro unlocks the structured clinical-evidence summary — study count, target patient population, and a tabular accuracy-metrics view drawn from peer-reviewed sources.
Peer-Reviewed Publications
ProPro unlocks the curated peer-reviewed publication list with PubMed cross-links — the citation backbone of every editorial verdict.
Post-Market & Regulatory Conditions
ProPro unlocks the post-market surveillance summary, recall record, and the conditions of approval that bound real-world use.
AI Algorithm Version History
ProPro unlocks the chronological record of algorithm version changes — what changed when, drawn from manufacturer changelogs and regulatory filings.
Regulatory Approvals
K243348
Class II
Safety Record
No recall, enforcement action or MAUDE adverse-event report naming Athelas, Athelas One or Athelas Home was found in the openFDA device databases, queried directly on 11 September 2026. The hazards that the FDA summaries themselves describe are worth reading. The reporting range starts at 1.0 x 10^3/µL WBC, and the home comparison contained no sample below that floor or below 21 per cent neutrophils, so the region where a clozapine or chemotherapy decision turns (an absolute neutrophil count near or under 1.0 x 10^9/L) is not shown in the public data. Against the XE-5000, Athelas One did not flag 5 of the 39 samples that the laboratory analyser flagged for leukopenia or leukocytosis. In the home error analysis, one HH! and one LL! range code were recorded as a successful test on the patient's side; results are withheld from patients by design and read only by the prescriber, so the prescriber's view is the safeguard. The device reports WBC and NEUT% only; the absolute neutrophil count is arithmetic the clinician performs. The labelling says the device is not to replace laboratory monitoring and that results are not the sole basis for managing leukopenia or neutropenia. A remote lockout lets the prescriber or manufacturer disable a device. Venous samples are stable for 24 hours; the summary observed degradation at 48 hours for both parameters.
Intended Use & Indications
Per the FDA indications for use (K243348): The Athelas Home is indicated for the quantitative determination of white blood cells (WBC) and Neutrophil percentages (NEUT%) in capillary whole blood from fingerstick for patient self-testing with results viewable by healthcare professionals, and in capillary or K2EDTA venous whole blood for multiple-patient use in point-of-care settings. For self-testing, the Athelas Home is intended to be used by a single person and should not be shared. The Athelas Home is only to be used with Athelas Test Strips. The Athelas Home is intended for adult patients (aged 21 and older) at risk of neutropenia. For self-testing patients with psychiatric conditions, clinical judgment should be exercised when deciding the end-user and based on the instructions for use (IFU), the treating physician should determine which patients are competent to perform the test by themselves. Results obtained with the Athelas Home should not be the sole basis for patient diagnosis, treatment, or management of leukopenia and neutropenia, and all results should be evaluated by a healthcare provider. Prescription Use Only.