ACKR1 and systemic lupus erythematosus: Thus, we examined the hypotheses that: (1) white cell count, haemoglobin (Hb) and platelet counts are lower in AA than EA patients with SLE, and (2) that the ACKR1 rs2814778-CC genotype accounts for the lower white cell counts but not for differences in platelet count and Hb concentration in patients of AA.