Treatment of pediatric idiopathic pulmonary hemosiderosis with low-dose cyclophosphamide.
OBJECTIVE
To report the safety and efficacy of long-term, low-dose cyclophosphamide therapy in a child with idiopathic pulmonary hemosiderosis (IPH).


METHODS
A 7-year-old boy diagnosed with IPH 4 years previously was initially prescribed prednisolone. Because he only had a transient response to prednisolone, oral cyclophosphamide 2 mg/kg/d was later added. A dramatic improvement was noted during the subsequent follow-up. One year after cyclophosphamide therapy, the patient suddenly developed thrombocytopenia (platelet count 75 x 10(3)/mm(3)), with the platelet count decreasing to 10 x 10(3)/mm(3) over the following 10 months. Cyclophosphamide was tapered to an alternating daily dosage of 1 mg/kg. The tapering resulted in a subsequent increase in the platelet count, which was maintained between 20 and 50 x 10(3)/mm(3) without occurrence of petechiae or spontaneous bleeding. Under this reduced dosing regimen, the disease has remained in remission for >1 year.


CONCLUSIONS
Due to the low prevalence of IPH, only limited data document the safety and efficacy of immunosuppressive therapy in treating this disease. Although our patient showed a good response to low-dose cyclophosphamide, he developed thrombocytopenia with its use. The mechanism is unclear, but it may be similar to that of high-dose cyclophosphamide-induced myelosuppression. Due to the development of thrombocytopenia, the use of cyclophosphamide was maintained under a reduced dosing regimen. The benefit of long-term immunosuppressive therapy is controversial, and more clinical evidence is required to support its continued usage.


CONCLUSIONS
Long-term, low-dose cyclophosphamide is effective in treating childhood IPH, but caution should be exercised due to the possible development of thrombocytopenia. Periodic monitoring of the platelet count in long-term treatment is recommended.
Huang
Shiou-Huei
SH
Department of Pharmacy, Chang-Gung Memorial Hospital, Kaohsiung, Taiwan.
Lee
Ping-Yu
PY
Niu
Chen-Kuang
CK
D002648:Child; D002675:Child, Preschool; D003520:Cyclophosphamide / Q000008:administration & dosage* / Q000627:therapeutic use; D006486:Hemosiderosis / Q000188:drug therapy*; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D008297:Male
D007166:Immunosuppressive Agents; D003520:Cyclophosphamide