Kuppe et al. Allergy, Asthma & Clinical Immunology 2012, 8:6 http://www.aacijournal.com/content/8/1/6 Page 4 of 6 Figure 3 Flow cytometric analysis of bone-marrow cells and morphology of antigen-presenting cells (APC) from long-term-cultures. (A) NKT (CD3+/CD56+ cells) were no longer present in the bone marrow of the patient. (B-C) Images show Giemsa-stained cytospin preparations of 28-day-cultured haemophagocytes with characteristic autophagy vacuoles and inclusion bodies containing undigested phagocytozed material (arrows). (D-I) Further FACS analysis revealed a high expression of CD63 on all BMCs and also an increased expression of CD11b on granulocytes. in the peripheral blood were already dramatically reduced (Table 2). The patient was maintained on 5 mg prednisolone and cyclosporine 2-6 mg/kg/d and to date he has had no further relapses for over a year. Discussion In acquired cases of macrophage activation syndrome (MAS), the clinical course is usually rapidly progressive with multi-system organ failure often occurring within Table 1 Laboratory Values Variable Haematocrit (%) White-cell count (10^6/l) Platelet count (10^6/l) Ferritin (μg/l) Triglycerides (mg/dl) IL2R (kU/l) IL6 (ng/l) CRP (mg/l) PCHE (U/l) Prothombin time (INR) Fibrinogen (g/l) fever episode 0,25 15,10 587 1043 68 > 7200 1500 >230 + 918 4,8 after 2 weeks 0,34 13,10 519 230 127 2000 250 53 3218 n.d. after 5 months 0,43 11,9 235 204 208 690 n.d. 10 9495 n.d. normal range 0.4–0.54 4.3–10.0 150–350 30–400 < 200 223–710 < 7 < 5 5320–12920 0.8–1.1 2.0–4.5