Transient Remission of Chronic Thrombocytopenic Purpura Induced by Dengue Virus Infection

Dr. Elena Putintseva, Department of Physiology, Institute of Hematology and Immunology, Apartado 8070, Habana 8 (Cuba) I have read with great interest the report of Schmidt et al. [1]. I also observed one case of shortterm remission of chronic idiopathic thrombocytopenic purpura (ITP), but contrary to the previous authors it was due to viral infection and not to a bacterial one. The patient was a 54year-old white woman with a 30-year history of chronic ITP, resistant to steroids. In January 1978, during the epidemic of Dengue (serotype 1) in Cuba, she presented with a 3-day history of fever, articular and ocular pain, nausea, equimosis and generalized petechiae. Moderate hepatosplenomegaly and generalized peripheral lymphadenopathy were present. A full blood count showed Hb 12.0 g/dl, WBC 6.2×109/1 (segmented cells 49%, monocytes 6%, lymphocytes 45%), platelets 6× 109/1. Serologic TSA (134%) 320 η 280240 200 H 0 160 1 120 § 80 u 5 40 < L· -I-«J ε o π 1 Γ 0 5 10 15 † Onset of fever Days Fig. 1. Clinical course of chronic ITP patient with Dengue virus infection. test for Dengue virus type 1 was positive. She was treated symptomatically. Two days later her full blood count showed Hb 13.3 g/dl, WBC 7.0 × 10V1 (stab cells 2%, segmented cells 15%, basophils 1%, monocytes 1 %, lymphocytes 81 %), platelets 8 × 109/1, reticulocytes 1%, hyperbasophil cells and hyaline lymphocytes were seen in peripheral blood. One week later the platelet count rose drastically to 273 × 109/1 (fig. 1). Serum of this patient, tested for thrombopoie-tic stimulatory activity (TS A) in a mouse bioassay system by measuring the incorporation of 75Se-selen-omethionine (75SeM) into platelets of assay mice [2], revealed elevated TSA levels (134% of control, p < 0.05). The remission was of short duration, and the platelet count reached the preinfection level 30 days later. In December 1981 she was splenectomized and a complete remission was achieved.