[Mast cell hyperplasia in bone oxalosis].

BACKGROUND

To assess by means of histomorphometry the incidence of bone marrow mast cell hyperplasia in patients with chronic renal failure and oxalosis.

MATERIAL AND

METHODS

Eighteen individuals were assigned to three groups: 6 (4 males and 2 females, aged 26.31 +/- 2.5 yrs) had chronic renal failure (CRF) and oxalosis of bone; 6 (1 male and 5 females aged 22.1 +/- 3.56 yrs) had CRF and 6 normal (5 males and 1 female aged 23 +/- 2.78 yrs) individuals entered the control group. Quantitative histologic assessments were completed in undecalcified sections of plastic embedded iliac crest bone biopsies stained by the Toluidine Blue method for identification of mast cells. The number of mast cells (cell/mm2 tissue area, x +/- sd) was determined by a semiautomatic image-analyzing system.

RESULTS

The number of mast cells was greater in patients with oxalosis of bone, 32.67 +/- 9.59, than in patients with CRF (20.84 +/- 5.04, p < 0.05) and than in the control group (3.26 +/- 1.03, p < 0.001).

CONCLUSIONS

Oxalosis of bone is associated with substantial increases in the number of mast cells in the bone marrow. Such a change is not related to chronic renal failure per se and does not appear to represent a non-specific response to bone marrow fibrosis. Mast cell accumulation may contribute to the development of bone marrow fibrosis seen in this disorder.