Sideroblastic anemia showing unique response to pyridoxine.
We treated and followed up for 6 years a patient with pyridoxine-responsive sideroblastic anemia. The patient was a boy age 1 year and 9 months, who was diagnosed on the basis of peripheral red cell morphology and an increased number of sideroblasts in the bone marrow. Bone marrow erythroblasts showed a marked reduction of delta-aminolevulinic acid synthase (ALA-S) activity. The response of the patient to pyridoxine and its active form, pyridoxal phosphate, was unique. After the first course of pyridoxal phosphate therapy (300 to 500 mg/day i.v. for 4 days), all hematological data were restored to normal and remained normal for 29 months without the further administration of pyridoxal phosphate. The second course of pyridoxal phosphate therapy (500 mg/day i.v. for 2 days) was effective for 6 months. The third, fourth, and fifth courses of the therapy consisted of daily oral pyridoxine hydrochloride at a dose of 180 mg/day for 4 to 6 weeks, and the respective periods of hematological remission were 7, 12, and greater than 18 months. These observations suggest the presence of a complicated ALA-S activating or inactivating system, or both, in our patient.
Murakami
R
R
Department of Pediatrics, Kobe University School of Medicine, Japan.
Takumi
T
T
Gouji
J
J
Nakamura
H
H
Kondou
M
M
D000624:5-Aminolevulinate Synthetase / Q000172:deficiency*; D000756:Anemia, Sideroblastic / Q000188:drug therapy* / Q000378:metabolism; D004900:Erythroblasts / Q000201:enzymology; D006418:Heme / Q000096:biosynthesis; D006801:Humans; D007223:Infant; D007501:Iron / Q000378:metabolism; D008297:Male; D011732:Pyridoxal Phosphate / Q000627:therapeutic use; D011736:Pyridoxine / Q000627:therapeutic use*
D006418:Heme; D011732:Pyridoxal Phosphate; D007501:Iron; D000624:5-Aminolevulinate Synthetase; D011736:Pyridoxine