| Project/Area Number |
07457233
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Hematology
|
|---|
| Research Institution | Osaka University |
|---|
Principal Investigator |
MACHII Takashi (1996) Osaka University Medical School, Associate Professor, 医学部, 助教授 (50124780)
木谷 照夫 (1995) 大阪大学, 医学部, 教授 (80028406)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MIZUKI Masao Osaka University Medical School, Assistant Professor, 医学部, 助手 (80283761)
OHNO Etsuko Osaka University Medical School, Assistant Professor, 医学部, 助手 (00273631)
TOKUMINE Yukihiro Osaka University Medical School, Assistant Professor, 医学部, 助手 (90207564)
待井 隆志 大阪大学, 医学部, 助教授 (50124780)
|
|---|
| Project Period (FY) |
1995 – 1996
|
| Project Status |
Completed (Fiscal Year 1996)
|
| Budget Amount *help |
¥6,900,000 (Direct Cost: ¥6,900,000)
Fiscal Year 1996: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1995: ¥4,400,000 (Direct Cost: ¥4,400,000)
|
|---|
| Keywords | PIG-A gene / GPI-anchored protein / paroxysmal nocturnal hemoglobinuria / aplastic anemia / CD59 / glycophorin A / mutation frequency / GPIアンカー / グリコフォリン遺伝子 / PNH / 造血不全 |
|---|
| Research Abstract |
1. Detection of CD59 deficient blood cells and analysis of the PIG-A gene in Japanese patients with aplastic anemia (AA)
Expressiona of a glycosylphosphatidylinositol (GPI) -anchored protein (CD59) on erythrocytes and granulocytes from 75 Japanese patients with AA was investigated by flow cytometry. CD59 deficient populations were detected in 23 (30.7%) of the patients ; 10 of 23 cases had features of paroxysmal nocturnal hemoglobinuria (PNH), which were not recognized in the other 13. PIG-A gene abnormalities were detected in all 10 cases tested by heteroduplex analysis. PIG-A mutations, identified by sequencing the relevant region in 7 cases, were different from each other. Two independent PIG-A mutant clones were detected in two cases, respectively.
2. Detection of a small population of CD59 deficient erythrocytes in AA
By analyzing expression of CD59 on a large number of (10^6) erythrocytes with FACScan, we could detect a very small population (less than 1%) of CD59 deficient erythrocytes in 5 of 21 patients with AA,who showed no GPI -anchored protein (GPI-AP) deficiency by usual immunophenotyping. The CD59 deficient populations were repeatedly detected in 3 of 4 patients studied 1,6 or 12 months later. Taken together with the data obtained by the usual immunophenotypic examination described above, as high as 52% of Japanese patients with AA was estimated to have GPI-AP deficient blood cells.
3. Mutation frequencies in AA and PNH
Mutation frequencies in AA and PNH,who have MN blood type, were studied employing in vivo erythrocyte glycophorin A (GPA) mutation assay. We detected increased mutation frequencies of the GPA gene in 4 of 9 AA and in 5 of 9 PNH cases. Our finding suggests that not only PIG-A gene but also other genes are hypermutable, and that mutagenic pressure and/or gene instability may contribute to the pathogenesis of these diseases.
|
