Possible feedback control of white blood cells: effect of splenectomy in Felty's syndrome

Feedback control of the white blood cell (WBC) count was analyzed in 20 cases reported by Coon, before and after splenectomy in Felty's syndrome. In only one case did the total white cell count fail to rise postsplenectomy, while in a second case the polymorphonuclear (poly) count did not exceed the preoperative value. Both of these patients had initial poly counts above 1000/mm3. If the preoperative poly count was 35% or greater of total WBC, the postoperative percentage was lower in five out of six cases. A comparison was made between pre- and postoperative poly counts, and three cases were noted to be underresponsive. However, two had a later rise in polys ('late responders'). A non-poly was defined as total WBC minus polys; a relationship was noted between pre- and post-operative non-polys, described by the difference between initial and postoperative counts. Thus, there is evidence for feedback control of the white cell count in Felty's syndrome after splenectomy.