Heterogeneity of mast cells in mastocytosis and inhibitory effect of ketotifen and ranitidine on indolent systemic mastocytosis.
BACKGROUND
Mastocytosis is a disorder of mast cell proliferation that occurs in both cutaneous and systemic forms. The most frequent site is the skin.


OBJECTIVE
The mast cell subtype of two patients with mastocytosis was investigated.


METHODS
Immunohistochemical studies were performed on the skin or gastric mucosa or both of the two patients. Blood and urine levels of various mediators were measured for one patient.


RESULTS
Mast cells containing tryptase and chymase were the only type seen in the skin lesions of an 11-month-old boy with urticaria pigmentosa. Mast cells containing tryptase were predominant in lesions of the skin and gastric mucosa of a 41-year-old man with indolent systemic mastocytosis. However, mast cells containing tryptase and chymase were predominant in the nonlesional and the normal skin of this patient. Tryptase-positive cells were more numerous in lesional skin than nonlesional skin and normal skin. Elevated blood and urine levels of various mediators were decreased by means of combination therapy with ketotifen and ranitidine.


CONCLUSIONS
In indolent systemic mastocytosis, mast cell dynamics involve only cells containing tryptase. Release of mediators from mast cells may be inhibited by means of combination therapy with histamine H1 and H2 receptor antagonists.
Kurosawa
M
M
Department of Dermatology, Gunma University School of Medicine, Maebashi, Japan.
Amano
H
H
Kanbe
N
N
Akimoto
S
S
Takeuchi
Y
Y
Yamashita
T
T
Hashimoto
T
T
Kurimoto
F
F
Miyachi
Y
Y
D000328:Adult; D001706:Biopsy; D053818:Chymases; D015232:Dinoprostone / Q000097:blood; D006632:Histamine / Q000097:blood; D006801:Humans; D007223:Infant; D007665:Ketotifen / Q000627:therapeutic use*; D015289:Leukotrienes / Q000097:blood / Q000652:urine; D008297:Male; D008407:Mast Cells / Q000473:pathology*; D008415:Mastocytosis / Q000473:pathology*; D011899:Ranitidine / Q000627:therapeutic use*; D012697:Serine Endopeptidases / Q000378:metabolism; D013929:Thromboxane B2 / Q000097:blood; D053802:Tryptases; D014582:Urticaria Pigmentosa / Q000473:pathology*
D015289:Leukotrienes; D013929:Thromboxane B2; D006632:Histamine; D011899:Ranitidine; D012697:Serine Endopeptidases; C083294:chymase 2; D053818:Chymases; D053802:Tryptases; D015232:Dinoprostone; D007665:Ketotifen