Intramuscular interstitial cells of Cajal associated with mast cells survive nitrergic nerves in achalasia


Natalia Zarate, Centre for Academic Surgery, 3rd Floor Alexandra Wing, The Royal London Hospital, Whitechapel, London E1 1BB, UK.
Tel: 0044 (0) 20 7377 7184; fax: 0044 (0) 20 7377 7346; e-mail:


Abstract  Achalasia is dominated by injury to inhibitory nerves. As intramuscular interstitial cells of Cajal (ICC-IM) are proposed to form functional units with nitrergic nerves, their fate in achalasia may be critically important. We studied the relationship between loss of nitrergic nerves and injury to ICC-IM in patients with achalasia and determined associations between ICC-IM and mast cells (MC), using quantitative immunohistochemistry and electron microscopy. Loss of neuronal nitric oxide synthase (nNOS) immunoreactivity was completed within 3 years of acquiring achalasia. Thereafter, progressive ultrastructural injury to remaining nerve structures was evident. Within the first 2 years, the number of ICC-IM did not decline although ultrastructural injury was already present. Thereafter, loss of ICC-IM occurred unrelated to duration of disease. Damage to ICC-IM appeared unrelated to nerve injury. A significant MC infiltration was observed in the musculature; the number of MC was positively related to the persistent number of ICC-IM. Mast cell formed close contacts with ICC-IM and piecemeal-degranulation occurred towards ICC-IM. In conclusion, injury to ICC-IM in achalasia is variable, but not related to duration of disease and injury to nitrergic nerves. MC are prominent and form close functional contact with ICC-IM which may be responsible for their relatively long survival.