Histological assessment of PAXgene tissue fixation and stabilization reagents.

Author(s): Kap M, Smedts F, Oosterhuis W, Winther R, Christensen N, Reischauer B, Viertler C, Groelz D, Becker KF, Zatloukal K, Langer R, Slotta-Huspenina J, Bodo K, de Jong B, Oelmuller U, Riegman P

Publication: PLoS One, 2011, Vol. 6, Page e27704

PubMed ID: 22110732 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to compare morphological preservation, histochemical and IHC staining, and in situ hybridization between 80 PFPE and FFPE tissue specimens from a wide variety of tissue types. The effects of duration of PAXgene fixation and room temperature block storage were also evaluated. FFPE tissue was fixed for 24 h while the majority of PAXgene tissue was fixed for 3 or 24 h and then stored in PAXgene tissue stabilizer reagent for 24 h up to 1 week at room temperature before paraffin processing. A subset of PAXgene-fixed tissue was stored for up to 5 days at 4 degrees C rather than room temperature before manual paraffin processing.

   Summary of Findings:

   Tissue-specific differences in morphological preservation were observed between PFPE and FFPE specimens, but they were generally minor and included instances where FFPE tissue was superior (stomach, small intestine, prostate, and lung) and where PFPE tissue was superior (liver, muscle, thyroid, adrenal gland and others). Artifacts observed in PFPE tissue compared to FFPE tissue included loss of red blood cells, cell shrinkage, and pyknosis. A decrease in contrast contributed to cases where FFPE tissue was inferior to PFPE tissue. Any differences observed between specimens fixed in PAXgene for 3 h rater than 24 h were also minor. However, the authors note that morphology scores given by 4 pathologists were very subjective. IHC staining using a panel of 33 antibodies was generally similar between FFPE and PFPE tissue. For a few antigens that showed better staining in FFPE tissue than PFPE tissue (CD3, CD20, CD68, KER8.18, and S100), omitting the antigen retrieval step improved IHC staining for the PFPE specimens. There were no differences observed when IHC staining was performed on sections from new PFPE blocks or blocks that had been stored for 2 years at room temperature. Periodic acid schiff (PAS) and resorcin fuchsin (RF) staining showed some cell specific differences between PFPE and FFPE specimens. Sirus red (SR) staining was crisper and of higher intensity in PFPE specimens than FFPE specimens. On the other hand, Gomori (GOM) staining was more intense in FFPE specimens than PFPE specimens and in PAXgene specimens fixed for 3 h rather than 24 h. HER2 in situ hybridization was successful in both PFPE and FFPE breast cancer tissue, but the signal was stronger in PFPE specimens.

   Biospecimens

   • Tissue - Adrenal Gland
   • Tissue - Bladder
   • Tissue - Bone Marrow
   • Tissue - Breast
   • Tissue - Colorectal
   • Tissue - Esophagus
   • Tissue - Adipose
   • Tissue - Kidney
   • Tissue - Liver
   • Tissue - Lung
   • Tissue - Lymph Node
   • Tissue - Muscle (Skeletal)
   • Tissue - Ovary
   • Tissue - Pancreas
   • Tissue - Placenta
   • Tissue - Prostate
   • Tissue - Skin
   • Tissue - Small Bowel
   • Tissue - Spleen
   • Tissue - Stomach
   • Tissue - Testis
   • Tissue - Thyroid Gland
   • Tissue - Uterus
   • Tissue - Other

   Preservative Types

   • Formalin
   • PAXgene

   Diagnoses:

   • Normal
   • Neoplastic - Benign
   • Neoplastic - Lymphoma
   • Neoplastic - Carcinoma

   Platform:

   Analyte	Technology Platform
   Morphology	H-and-E microscopy
   Morphology	Light microscopy
   Protein	Immunohistochemistry
   RNA	In situ hybridization

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Acquisition	Biospecimen location	Adrenal gland Bladder Bone marrow Breast Colon Esophagus Fat Kidney Liver Lung Lymph nodes Muscle Ovary Pancreas Placenta Prostate Rectum Skin Small intestine Spleen Soft tissue Stomach Testis Thyroid Uterus
   Biospecimen Preservation	Type of fixation/preservation	Formalin (buffered) PAXgene
   Biospecimen Preservation	Time in fixative	3 h 24 h
   Storage	Storage duration	0 d 2 y
   Analyte Extraction and Purification	Antigen retrieval	Heat induced epitope retrieval None
   In situ hybridization Specific	Targeted nucleic acid	HER2
   Light microscopy Specific	Type of tissue stain	PAS RF SR GOM

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