不妊症患者における精漿中LDH-C4アイソザイム活性の臨床的有用性の検討

Abstract

無精子症または乏精子症と診断された男性99名(21～55歳)の精漿を検体に, ゲル電気泳動による乳酸脱水素酵素(LDH)アイソザイムキットを用い, 不妊症患者の精漿中のLDH-C4を定量した.対照群の健常者10名の血清中総LDHは99.5±5.6IU/l, 不妊症患者99名の精漿中の総LDHは2487±1384IU/lと健常者に比べ, 約25倍の値を示した.無精子症7例中4例の精漿中にLDH-C4が検出された.精漿LDH-C4は不妊症患者の精巣の精子形成能と密接な関係を持っており, 男子不妊症の診断, 治療において従来のセミノグラムを補う有用な指標に成り得ると考えられる

Lactate dehydrogenase C4 (LDH-C4) is the specific isozyme of LDH produced by germ cells. We measured LDH-C4 activity in seminal plasma from infertile men with oligozoospermia or azoospermia using gel electrophoresis. Total LDH activity in seminal plasma from infertile patients (n = 99) was 2, 487 +/- 1, 384 IU/l (mean +/- SD). LDH-C4 isozyme activity was detected in 63 out of 75 seminal plasma samples from infertile patients with a mean of 383 +/- 356 IU/l (13.8 +/- 8.6% of total LDH). Sperm count was positively correlated with LDH-C4 (r = 0.298; P < 0.05), but not with any other LDH isozymes or with total LDH. Seminal LDH-C4 was significantly lower in patients with varicoceles (253 +/- 223 IU/l) than without varicoceles (474 +/- 262 IU/l). Six azoospermia patients were treated with hCG and hMG. Three out of four patients whose seminal plasma revealed LDH-C4 activity responded to the treatment, whereas none of the other two patients without seminal LDH-C4 activity did. These results indicate the clinical usefulness of seminal LDH-C4 as a potential marker for seminal epithelium activity in the diagnosis and treatment of male infertility.