PT  - JOURNAL ARTICLE
AU  - Tetsurou Hirata
AU  - Mikihiro Fujioka
AU  - Kenji A Takahashi
AU  - Takeshi Asano
AU  - Masashi Ishida
AU  - Kiyokazu Akioka
AU  - Masahiko Okamoto
AU  - Norio Yoshimura
AU  - Yoshiko Satomi
AU  - Hoyoku Nishino
AU  - Yoshio Hirota
AU  - Shigeo Nakajima
AU  - Shigeaki Kato
AU  - Toshikazu Kubo
TI  - Low molecular weight phenotype of Apo(a) is a risk factor of corticosteroid-induced osteonecrosis of the femoral head after renal transplant.
DP  - 2007 Mar 01
TA  - The Journal of Rheumatology
PG  - 516--522
VI  - 34
IP  - 3
4099  - http://www.jrheum.org/content/34/3/516.short
4100  - http://www.jrheum.org/content/34/3/516.full
SO  - J Rheumatol2007 Mar 01; 34
AB  - OBJECTIVE: Osteonecrosis of the femoral head (ONF) is a necrosis due to disruption of the blood flow. The disease often occurs in association with corticosteroid treatment. The pathology of corticosteroid-induced ONF is unclear, although abnormalities in the coagulation and fibrinolytic systems or in the lipid metabolism have been reported to be involved. We examined the relationships between development of ONF and genetic variations and plasma level of lipoprotein(a) (Lp(a)), which is closely involved in the coagulation and fibrinolytic systems and lipid metabolism. METHODS: The study population consisted of 112 renal transplant patients undergoing corticosteroid treatment. Their apolipoprotein (a) [apo(a)] isoform was determined by Western blotting, and patients were classified into low molecular weight (LMW) or high molecular weight (HMW) groups. The plasma Lp(a) level was measured. Patients were also examined for 3 single-nucleotide polymorphisms (SNP), -773 (G/A), +93 (C/T), and +121 (G/A). Relationships between these 3 genetic factors of Lp(a) and ONF development were examined using statistical methods including multivariate analysis. RESULTS: A strong relationship was observed between the apo(a) molecular weight phenotype and ONF development, with an increased risk of ONF development for the LMW group (adjusted odds ratio 5.75, 95% CI 1.76-18.74, p = 0.0038). No significant relationships were observed between ONF and plasma Lp(a) level and SNP. CONCLUSION: Apo(a) molecular weight phenotype would be a useful predictor of ONF that develops after corticosteroid treatment.