Haji Siyamuddin flags HIL index
- Haji Siyamuddin Ansari used an X post to spotlight the hemolysis‑icterus‑lipemia, or HIL, index as a specimen-quality check that labs could apply beyond serum to body fluids and other cytology material. - The strongest published data are in body fluids: a 2,752-specimen review found severe icterus and lipemia can be more common there, while a 2024 study set lower interference limits for six analytes. - HIL flags are already standard guidance for serum and plasma, but extending them to nonblood specimens remains a lab-by-lab practice rather than a universal rule. (clsi.org)
The hemolysis-icterus-lipemia index is a lab quality check for blood contamination, bilirubin, and fat in a sample, and Haji Siyamuddin Ansari is arguing it belongs in cytology workflows too. (clsi.org) In plain terms, the index is a traffic light for sample interference: hemolysis means red-cell breakup, icterus means excess bilirubin, and lipemia means fat clouding that can distort instrument readings. (clsi.org) (pubmed.ncbi.nlm.nih.gov) Clinical and Laboratory Standards Institute guidance describes HIL indices as automated checks used to annotate affected results or reject a specimen or result when interference crosses a cutoff. The document is written for serum and plasma, where most analyzers already measure these indices routinely. (clsi.org) The gap Ansari is pointing to is outside routine blood testing, in specimens such as pleural fluid, ascites, urine, and sputum that often move through cytology and molecular pipelines with less standardized HIL screening. Published guidance for nonblood cytology handling focuses heavily on collection, fixation, and cell-block preparation rather than a universal HIL rule. (pmc.ncbi.nlm.nih.gov 1) (pmc.ncbi.nlm.nih.gov 2) There is evidence that body fluids carry the same interference problem. A University of Iowa review of 2,752 body-fluid specimens found HIL distributions were broadly similar to serum and plasma, but body fluids showed a higher proportion of samples with severe icterus or lipemia. (pmc.ncbi.nlm.nih.gov) That study also found lactate dehydrogenase was the body-fluid test most commonly affected by hemolysis. In pleural fluid, false lactate dehydrogenase elevation from hemolysis can misclassify a transudate as an exudate under Light’s criteria. (pmc.ncbi.nlm.nih.gov) A 2024 American Journal of Clinical Pathology study pushed the point further by testing body-fluid analytes directly on a Roche cobas instrument. It found lower interference thresholds than blood-package inserts for six analytes, including lactate dehydrogenase, cholesterol, triglycerides, total protein, amylase, and albumin. (academic.oup.com) That paper also found dilution was a weak fix. Only cholesterol and triglycerides in icteric samples returned to baseline after dilution, while other interfered results did not reliably recover. (academic.oup.com) For cytology labs, the practical link is specimen triage. Reviews of effusion cytology and molecular testing both say downstream success depends heavily on preanalytic handling, specimen quality, and how much usable material reaches the cell block or nucleic-acid extraction step. (pmc.ncbi.nlm.nih.gov 1) (pmc.ncbi.nlm.nih.gov 2) (pmc.ncbi.nlm.nih.gov 3) The published literature does not show a universal cytology standard that says every urine, sputum, or body-fluid specimen must get an HIL index before processing. What it does show is a growing technical case that interference limits in nonblood fluids can differ from blood, and that labs setting rejection or comment thresholds need specimen-specific validation. (clsi.org) (academic.oup.com) So the post is less a new guideline than a push to import an established chemistry safeguard into messier cytology practice. The evidence base is strongest for body fluids today, and the next step for labs is deciding whether to build HIL checks into their own preanalytic rules before a compromised sample reaches staining or sequencing. (clsi.org) (pmc.ncbi.nlm.nih.gov)
