Re: GMS help
Cheryl Powell, BS, HTL located Freida Carson's article in the Journal of
Histotechnology in which she probably answers the question we've been asking
about substituting periodic acid for chromic acid in the Gomori methenamine
Dr. Carson lengthened the time in periodic acid and increased the
temperature, and demonstrated that this change in the procedure both
decreased non-specific staining, and increased the likelihood that
Histoplasma capsulatum would be demonstrated.
"Our experience indicated that 1% periodic acid oxidation for 5 to 30 min at
room temperature is insufficient for consistent detection of Histoplasma
capsulatum, although adequate staining of Aspergillus sp. is obtained.
Consequently, false-negative results may be reported. We recommend that the
period of oxidation with periodic acid should be extended to 1 hr at 56 to
60°C to ensure consistent demonstration of H. capsulatum. These observations
also underscore the importance of the use of matched positive controls when
analyzing fungal stains."
The authors did exactly what I suggested in an earlier posting: after an
index case brought the problem to their attention, they recovered seven
earlier cases from their files, and showed that the periodic acid technique
as commonly done failed to demonstrate the organisms in 3 out of the 8 cases.
I'm particularly impressed by their index case, in which the patient had
overwhelming active histoplasmosis in the bone marrow, with no staining with
periodic acid GMS at room temperature.
Could someone on this list with adequate archival material duplicate this
study and report it to us? - I would suggest calling this modified periodic
acid technique "Carson's GMS" unless Dr. Carson insists we blame it on her
junior authors! Are the reprints still available?
Inconsistent Detection of Histoplasma capsulatum with Periodic Acid Oxidation
in the Grocott Methenamine-Silver Nitrate (GMS) Fungus Stain
Freida L. Carson, Jerry Fredenburgh, and John E. Maxwell
1. Department of Pathology, Baylor University Medical Center
2. Richard-Allan Scientific Kalamazoo MI
3. Glenwood Regional Medical Center, West Monroe LA
J Histotechnol [June] 1999;22:119
Address reprint requests to:
Jerry Fredenburgh, Richard-Allan Scientific, 225 Parsons Street, Kalamazoo MI
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