Frequency of the 816D>V c-kit mutation in patients with recurrent anaphylaxis in comparison to two control groups
| Patient group . | n . | c-kit mutation, no. (%)* . | CD25+, no. (%) . |
|---|---|---|---|
| Mastocytosis† | 48 | 25/30 (83) | 39/45 (87) |
| Without anaphylaxis | 36 | 18/22 (82) | 29/34 (85) |
| With anaphylaxis | 12 | 7/8 (88) | 10/11 (91) |
| ″Idiopathic″ anaphylaxis‡ | 12 | 3/6 (50) | 5/12 (42) |
| With clonal mast cells§ | 5 | 3/4 (75) | 5/5 (100) |
| True idiopathic | 7 | 0/2 (0) | 0/7 (0) |
| Nonmastocytosis, nonanaphylaxis | 12 | 0/5 | 0/10 |
| Patient group . | n . | c-kit mutation, no. (%)* . | CD25+, no. (%) . |
|---|---|---|---|
| Mastocytosis† | 48 | 25/30 (83) | 39/45 (87) |
| Without anaphylaxis | 36 | 18/22 (82) | 29/34 (85) |
| With anaphylaxis | 12 | 7/8 (88) | 10/11 (91) |
| ″Idiopathic″ anaphylaxis‡ | 12 | 3/6 (50) | 5/12 (42) |
| With clonal mast cells§ | 5 | 3/4 (75) | 5/5 (100) |
| True idiopathic | 7 | 0/2 (0) | 0/7 (0) |
| Nonmastocytosis, nonanaphylaxis | 12 | 0/5 | 0/10 |
Data on mast-cell CD25 expression, another marker of clonal mast-cell disease, are provided for comparison.
816D>V except in 2 patients with mastocytosis (with or without anaphylaxis) who had either a 816D>Y or a 522F>C mutation. Clinicopathologic features of the patient with 522F>C mutation has been reported in detail.12 All mutational analyses were performed on bone marrow aspirates. Nucleic acid isolation from paraffin-embedded bone marrow biopsy tissue (fixed in B-plus) of 6 patients with anaphylaxis was attempted,13 but was not successful.
Patients readily diagnosed with mastocytosis due to UP skin lesions and/or multifocal mast-cell clusters in the bone marrow.
Patients with neither urticaria pigmentosa nor mast-cell clusters in bone marrow, who were referred for evaluation of multiple recurrent anaphylactic episodes. Further study of bone marrow mast cells for minor diagnostic criteria in this subgroup revealed 5 patients with various clonal mast-cell markers as reported in detail in Table 2. The remaining 7 patients in this subgroup had no clonal mast-cell markers, thus representing the true idiopathic population.
See Table 2.