Can splenectomy be avoided in recently diagnosed adults with immune thrombocytopenia (ITP)?
Bronchoalveolar Lavage Fluid
Intravenous (IV) anti-D is an established treatment for Rh+, non-splenectomized patients (pts) with ITP. This study explores whether it is an appropriate interim therapy for recently-diagnosed (within 1 to 12 months (mos)) adults and whether splenectomy can be avoided by its use. Methods: 28 Rh+, HIV- pts with ITP were treated with IV antiD (50 or 75mcg/kg) whenever their platelet (pit) counts (ct) fell to < 30,000/ul (30K) and were followed for at least 18 mos or until splenectomy. "Responders" achieved a pit increment (incr) 20K and pit ct 30K within 1 week of treatment. Patients were considered "off treatment" if they had stable pit cts 30K for 6 months. Plasma glycocalicins (GC's), the extramembranous portion of GPlba, were measured by sandwich ELISA at study initiation, as high GC's may indicate high pit turnover and increased disease activity in pts with ITP. Results: Pts were followed for 5-44 mos (mean 22). 26/28 pts responded to the first infusion (inf) of anti-D and 20 (71%) consistently responded to anti-D. One pt was lost to follow-up at 10 mos (and is excluded from the table). Only one pt stopped anti-D due to toxicity (anemia and chills); no significant hemolysis or severe adverse event was seen. Greater pit incr. and duration of response was seen in the patients receiving 75mcg/kg. Long Term Num Initial Pit GC(mg/ml) Hb decrease PU Incr 1st Duration 1st Outcome Pts Cc (KAil) Day 7-0 (g/dl) Inf(K/ul) Inf (days) Splenectomy 6 9(av)+/-6.6 (sd) 0.9+/-0.2 1.8W-0.7 69+/-103 21+/- 16 On Treatment 12 15+/-7.3 1.3+/-0.8 1.5+/-0.8 122 +/- 115 44+/-61 Off Treatment" 9 21" V- 6.2 1.1+/-0.2 1.7+/-0.9 132 +/- 102 52+/-43 These 9 pts have been off treatment for a mean of 16 mos; 3 pts have had normal pit cts for 4 mos & 6 have cts 100KAil. Six of the 12 still requiring intermittent treatment receive only anti-D at intervals of 8 weeks. Pts who underwent splenectomy had lower initial pit cts than those able to discontinue treatment (p=0.01). GC levels correlated with duration of response to anti-D (p=0.016). In conclusion, anti-D is effective in the great majority of Rh+, non-splenectomized pts. With or without other therapy, anti-D can be used to prevent or delay splenectomy in pts with recently diagnosed FTP, especially those with pit counts 14K at diagnosis, by giving these pts a chance to spontaneously improve. The longer duration of response to anti-D in pts with higher pit turnover supports the hypothesis that interfering with pit destruction will have greater impact in states of increased thrombopoiesis.