The clinical course of some patients with sickle cell disease may be explained by concurrent Mast Cell Activation Syndrome (MCAS). This may be associated with an increased level of systemic inflammation.
Patient selection: sickle cell disease (SCD)
Reasons to suspect mast cell activation in a patient with SCD:
(1) poor clinical phenotype
(2) symptoms inconsistent with typical SCD and more consistent with MCAS
(3) laboratory evidence of mast cell activation
(4) positive response to MCAS-targeted therapy
Typical laboratory findings:
(1) normal serum tryptase level
(2) normal plasma histamine levels
(3) elevated prostaglandin D2 (PGD2) levels
(4) elevated serum heparin levels
(5) normal urine N-methylhistamine level
(6) mild monocytosis and/or eosinophilia
