Clinical Notes

Short practical lessons derived from advanced cytometry learning sessions, checked against published sources before editorial release. Learn → verify → synthesise → publish.

These are educational syntheses, not patient cases or employer procedures. Source session numbers are preserved; no original session date has been inferred.

Detection is not quantification

Derived from advanced session 1. A detected population and a reliable numerical estimate are separate claims. Before reporting a rare cluster, check the validated background rule, phenotype, evaluable denominator and specimen adequacy. A count such as 15 events is not a universal positive/negative threshold. If the assay permits a detected-below-quantification category, use it without presenting an unjustifiably precise value. CFCM question: what evidence supports the category being reported?

Correlation is not agreement

Derived from advanced session 6. Two procedures can correlate closely while differing systematically. First harmonise the measurand and denominator; CD4 as a percentage of T cells is not CD4 as a percentage of lymphocytes. Then assess bias and uncertainty against prespecified limits, investigating clinically meaningful discordance. A familiar comparator is not automatically ground truth. CFCM question: could the observed difference change interpretation?

A timing tolerance is a claim

Derived from advanced session 7. An operational interval around a nominal incubation time needs evidence for the modified procedure. Normal samples alone may fail to challenge dim or abnormal populations. Deliberately examine relevant boundary conditions and interactions, and assess reportable decisions rather than only average fluorescence. Document authorisation and change control before routine use. CFCM question: were the conditions most likely to fail actually tested?

Author and disclosure

Professional background: Juan Manuel Ojeda has professional experience with Sysmex España in clinical flow cytometry and now works as a freelance consultant. CFCM is his independent editorial project; its views do not represent Sysmex or imply company endorsement. Employer or client confidential information and intellectual property are excluded.