Long-term response and outcome following immunosuppressive therapy in thymoma-associated pure red cell aplasia: a nationwide cohort study in Japan by the PRCA collaborative study group.
BACKGROUND
Thymoma-associated pure red cell aplasia (PRCA) accounts for a significant proportion of cases of secondary PRCA and immunosuppressive therapy has been reported to be useful in this condition. However, because of its rarity, the long-term response and relapse rates after immunosuppressive therapy are largely unknown, and optimal management of this disorder remains unclear. The aim of this study was to collect more information on the outcome of patients with thymoma-associated PRCA.


METHODS
We conducted a nationwide survey in Japan. From a total of 185 patients, comprising 73 with idiopathic and 112 with secondary PRCA, 41 patients with thymoma were evaluated for this report. End-points of this study were the response rate, duration of the response after immunosuppressive therapy and overall survival.


RESULTS
Surgical removal of thymoma was reported in 36 patients, 16 of whom developed PRCA at a median of 80 months post-thymectomy. First remission induction therapy was effective in 19 of 20 patients treated with cyclosporine, 6 of 13 patients treated with corticosteroids and 1 of 1 treated with cyclophosphamide. No cyclosporine-responders relapsed within a median observation period of 18 months (range; 1 to 118 months). Relapse of anemia was observed in three corticosteroid-responders who did not receive additional cyclosporine. Only two patients were in remission after stopping therapy for 19 and 67 months. The estimated median overall survival time of all patients was 142 months.


CONCLUSIONS
Thymoma-associated PRCA showed an excellent response to cyclosporine and cyclosporine-containing regimens were effective in preventing relapse of anemia. It does, however, remain uncertain whether cyclosporine can induce a maintenance-free hematologic response.
Hirokawa
Makoto
M
Division of Hematology and Oncology, Department of Medicine, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan. mhirokawa@hos.akita-u.ac.jp
Sawada
Ken-ichi
K
Fujishima
Naohito
N
Nakao
Shinji
S
Urabe
Akio
A
Dan
Kazuo
K
Fujisawa
Shin
S
Yonemura
Yuji
Y
Kawano
Fumio
F
Omine
Mitsuhiro
M
Ozawa
Keiya
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015897:Comorbidity; D016572:Cyclosporine / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D007564:Japan; D008297:Male; D008875:Middle Aged; D012010:Red-Cell Aplasia, Pure / Q000150:complications / Q000473:pathology* / Q000628:therapy*; D013945:Thymoma / Q000150:complications / Q000473:pathology* / Q000628:therapy*; D016896:Treatment Outcome
D007166:Immunosuppressive Agents; D016572:Cyclosporine