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Quantifying mast cells in bladder pain syndrome by immunohistochemical analysis
Author(s) -
Larsen Mathilde S.,
Mortensen Svend,
Nordling Jørgen,
Horn Thomas
Publication year - 2008
Publication title -
bju international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.773
H-Index - 148
eISSN - 1464-410X
pISSN - 1464-4096
DOI - 10.1111/j.1464-410x.2008.07576.x
Subject(s) - medicine , tryptase , mast cell , interstitial cystitis , pathology , systemic mastocytosis , biopsy , staining , urinary bladder , urinary system , immunohistochemistry , urology , immunology
OBJECTIVES To evaluate a simple method for counting mast cells, thought to have a role in the pathophysiology of bladder pain syndrome (BPS, formerly interstitial cystitis, a syndrome of pelvic pain perceived to be related to the urinary bladder and accompanied by other urinary symptoms, e.g. frequency and nocturia), as >28 mast cells/mm 2 is defined as mastocytosis and correlated with clinical outcome. PATIENTS AND METHODS The current enzymatic staining method (naphtolesterase) on 10 µm sections for quantifying mast cells is complicated. In the present study, 61 patients had detrusor biopsies taken between 2002 and 2005; the patients were given a clinical score, and sections of the biopsy stained with (i) naphtolesterase on 10 µm sections, staining every third section, or (ii) immunohistochemically with antitryptase on both 10 µm and 3 µm sections, with two and six unstained sections between, respectively. Mast cells were counted according to a well‐defined procedure. RESULTS The old and the new methods, on 10 and 3 µm sections, showed a good correlation between mast cell counts. When using tryptase staining and 3 µm sections, the mast cell number correlated well with the clinical score (Spearman’s ρ 0.576; 95% confidence interval 0.155–0.820) and 27 mast cells/mm 2 was the threshold suggesting mastocytosis. CONCLUSIONS We recommend taking biopsies from the detrusor of patients with suspected BPS and examining them with tryptase‐stained 3 µm thick sections, with every seventh section used for quantification; 27 mast cells/mm 2 is considered indicative of mastocytosis.