血漿中HIV-RNA量の増加とともにAIDS痴呆コンプレックスが進行した1症例

A Patient with HIV Showing a Positive Relationship between the Course of AIDS Dementia Complex and the Level of HIV-RNA in Plasma

【抄録】　AIDS痴呆コンプレックス（ADC）またはHIV脳症は中枢神経系へのHIV感染症によって引き起こされることが知られているが，ADCの重症度と血漿中のHIV-RNA量との関係は明らかではない。本症例は，免疫機能が重度に低下したHIV感染症の32歳男性で，CDC分類でC3期に相当していた。本症例は痴呆を示し，ADCと診断された。ADCによる症状は，血漿中HIV-RNA量の増加に伴って進行した。脳波上は，基礎律動が徐波化し，MRI，T2イメージでは脳萎縮と皮質下における異常高信号域が認められた。本症例では，ADCの進行と血漿中HIV-RNA量との問には正の相関が観察された。ただ，髄液中HIV-RNA量は測定しておらず，不明であった。

　ほとんどの抗HIV薬は血液・脳関門を経て十分に中枢神経系へ移行することは困難である。このように抗HIV薬の中枢神経系への移行率は低値であることから，血漿中と髄液中とではIHV-RNA量に解離が起こる可能性がある。また，血漿中と髄液中では薬剤耐性が異なるHIV株が出現する可能性もある。以上を踏まえると，今後ADCの進行と，血漿中さらには髄液中HIV-RNA量，および薬剤耐性との関係を検討する必要がある。

　Although AIDS dementia complex (ADC) or HIV encephalopathy is known to be caused by infection by HIV (human immunodeficiency virus) of the central nervous system (CNS), the relationship between the severity of ADC and the level of HIV-RNA in plasma is not known.

　A 32 year-old man with HIV infection had a severely suppressed immune function, and was classified as category C 3 at the Center for Disease Control immune classification. His initial depressed mood gradually disappeared, but his memory became disturbed. In addition, he showed slowing of speech, thought, and behavior. His mood fluctuated and his ability to understand and concentrate deteriorated. He became demented, and ADC was diagnosed. These symptoms of ADC gradually progressed during a period of two years, accompanied by elevation of HIV-RNA levels in plasma. On electroencephalography, the frequency of basic activity became less than it was before the onset of ADC. Moderate brain atrophy and abnormal high intensity in the subcortical area were found on T 2-weighted MRI images.

　A correlation between progression of ADC and plasma HIV-RNA levels was observed in this case, although HIV-RNA levels in his cerebrospinal fluid (CSF) were not repeatedly investigated.

　Most anti-retroviral agents are not able to penetrate sufficiently into the CNS through the blood brain barrier. The insufficient penetration of anti-retroviral agents may cause the disassociation of HIV-RNA levels in plasma and in CSF, and HIV variants may cause the difference in drug resistance between plasma and CSF. Taking these facts into consideration, it is necessary to show the correlation between progression of ADC, and HIV-RNA levels and drug resistance in plasma and in CSF.