実験的単純ヘルペスウイルス脳炎におけるAra-Aの治療効果—脳脊髄液および血清中抗体価の推移と病理

EXPERIMENTAL HERPES SIMPLEX VIRUS ENCEPHALITIS:EFFECT OF ARA-A TREATMENT, AND SEROLOGICAL AND PATHOLOGICAL STUDY

　抄録　ウサギの実験的単純ヘルペスウイルス（HSV）脳炎の系で，Ara-A投与の治療効果を検討した。同時に脳脊髄液（CSF）および血清中の抗体の動きを追い，その診断的意義を検討し，あわせて免疫螢光法によるウイルス抗原の検索と病理組織学的検索を行なった。HSV I型を眼角膜に感染させると，数日で大量の眼脂が出，脳炎症状が現れる。抗体をELISA法でみると，CSF中では感染4〜6日目にかけて，また血清中では2日程遅れて上昇を示した。Ara-AをHSV感染3日目に投与しはじめると生存率と予後がきわめて良かった。しかし6日目に開始すると，生存率は高めえても眼脂や神経症状の改善には余り効果的ではなかった。途中死亡した例では，感染経路各部（角膜，三叉神経節，橋部，大脳）にウイルス抗原がみられたが，生存例では認められなかった。また上記組織の神経細胞に変性，核内封入体がみられた。以上よりELISA法によるCSF中の抗体測定は感度が良く，早期診断を可能にし，かつAra-Aの早期開始が生存率を高め，予後を良好にすることを明らかにした。

The effect of Ara-A treatment on the experi-mentally induced herpes simplex virus (HSV) ence-phalitis in rabbits was examined. Simultaneously practical value of enzyme-linked icnmunosorbent assay (ELISA) for rapid diagnosis was tested to find an early rise of antibody in cerebrospinal fluid (CSF) and serum in connection with an adop-tion of Ara-A administration. F-ISV encephalitis was produced by inoculation with type-1 HSV into the bilateral corneas of the eyes. A large amount of pus and typical neurological signs cha-racteristic to encephalitis appeared after several days of infection. Ara-A therapy begun at the 3rd day of infection clearly increased the survi-val rate (90%) and improved the clinical signs, but the start of the drug at the 6th day could only increase the survival rate (60%) without cure of the clinical symptoms. ELISA could catch the early rise of IgG antibody in CSF from 3-4 days and in serum from 4-6 days after infection. Ara-A didn't interfere the antibody production. Viral antigens were found in the corneal epithelia and propria, neurons and Schwann's cells of trigeminal ganglia, neurons and glial cells of pons and cereb-rum, especially in hippocampal nuclei. Typical Cowdry A and full type intranuclear inclusion bodies in the neurons were observed in the above tissues with infiltration of large amount of small round cells. In conclusion, Ara-A therapy in HSV encephalitis at the early stage of infection was quite effective for cure and the ELISA method is a useful tool for detection of early antibody rise in CSF and serum.