Clinical characteristics of Inmune Thrombocytopenic Purpura

Abstract

Background: Inmune thrombocytopenic purpura (ITP) is usually self-limited, but may have a chronic evolution when persisting more than 6 months (10-20% cases). Its treatment is controversial and few national data is available.

Objective: To obtain knowledge on clinical and laboratory characteristics of ITP, its relationship with chronic evolution and treatment.

Patients and Methods: Retrospective study that includes patients with diagnosis of ITP between March 1998 and February 2003 at Luis Calvo Mackenna Children's Hospital. We registered at diagnosis: sex, age, symptoms and treatment strategy. Platelet count (PC) was done at diagnosis, between day 15-60 and after 6 months. Fisher test and Odds ratio were calculated.

Results: Median age was 4,4 years (0,7-16,1), initial PC was £ 20 000/mm³ in 37/52 cases. No cerebral bleeding was found. Observation strategy was used in 34/52 cases, steroids in 17/52 cases and steroids + inmunoglobulin in 1 case. The 6-months follow up was completed in 48/52 cases; 11 patients had a chronic evolution. We found an association with PC day 15 £ 20 000/mm³ (p = 0,01 OR = 9 IC95% 1,26-80,16) and PC day 60 £ 50 000/mm³ (p = 0,0000003 OR = 124 IC95% 7,77-4951,52).

Conclusions: Most of our patients were successfully managed with the observation strategy. 23% cases had a chronic evolution and PC day 15 £ 20 000/mm³ and PC day 60 £ 50 000/mm³ are considered risk factors.