Mast cells in pulmonary haemosiderosis.

Abstract

SUMMARY A case of childhood pulmonary haemosiderosis with a fourfold increase in mast cells in the lung is described. This finding is discussed in relation to the pathogenesis of the disease. Comparison is made with controls, and the use of disodium cromoglycate is advocated. Treatment with disodium cromoglycate began and resulted in regression of dyspnoea, maintenance of a steady haemoglobin value, and clinical cessation of pulmonary bleeding for a period of 14 weeks. An episode of massive intrapulmonary haemorrhage then occurred and the patient died. At necropsy the lungs showed the characteristic brown induration with superimposed recent bleeding. Abnormalities shown by light and electron microscopy were similar to those seen in the lung biopsy, with alterations in the mast cells consistent with cromoglycate treatment.3 The other organs, in particular the kidneys, were normal. Lung tissue from this child was compared with that from three adults with PH (one case each of mitral stenosis, immune complex mediated PH, and adult IPH) and three normal adult controls (Fig.

Childhood Interstitial Lung Disease

“…84 Mast cells produce mediators that have smooth muscle constrictive properties: 78 therefore mast cells and their mediators may provide at least a partial explanation for the finding of airways obstruction in such patients. 62,63,79,83 The increased number of pulmonary parenchymal and peribronchiolar mast cells in our patients with CILD appears to be relatively specific to these illnesses and is not a sign of general lung damage. Mast cells were not abundant in lung specimens from patients with other severe lung diseases, such as bronchopneumonia, asthma, cystic fibrosis, or congenital heart disease with PHT.…”

“…80 Also, leukotriene C 4 and D 4 have notable effects on peripheral bronchoconstriction 81 and arachidonic acid products produced from mast cells 78 ' 82 can produce airway smooth muscle constriction. Increased airways reactivity has been found in CILD patients, 83 in adults with ILD, 78,79 and in animal models of ILD. 84 Mast cells produce mediators that have smooth muscle constrictive properties: 78 therefore mast cells and their mediators may provide at least a partial explanation for the finding of airways obstruction in such patients.…”