Strange recoveries, and... 奇妙な復帰、そして……

2. Strange rumors ２ 奇妙な噂

"No, I'm not sure," Kanzaki said. "I think it's a clone if it's a science fiction story."

Miyahara said that there is no direct relationship, but in fact there is a relationship between organ trade and youth prostitution. Some children who were given large doses of hormones for the purpose of abnormal erection and as a result became useless due to side effects such as hypotension / heart disease / cerebral infarction, or children who did not listen to the orders of the prostitute owner were killed as organ donors. In order to save the lives of rich people in developed countries, including Japan, children will be pulled out of their organs for sale and eventually killed. The reality is not exactly known, but the fact that there are endless arrests on the ground suggests that it is a dangerous, but delicious Dark business that makes money without difficulty. People like profits. And it is always the socially vulnerable who suffer.

"That's right.

Certainly, if it is a clone, there will be no rejection because it is essentially the same body as itself. "

Due to ethical issues, legislation will probably need to be amended to adapt to society the administratively difficult to perform bioclonal transplants, even if technically possible. And the tragedy of the poor, , who are not children, will continue unless biological clones can be forcibly used as transplanted organs.

With that in mind, Miyahara was trapped in despair.

"Well, if it's a clone ..."

Miyahara receives Kanzaki's words and switches his head.

"There is a possibility"

There are three main types of rejection in organ transplantation.

One of them is hyperacute rejection, which mainly involves the donor's HLA (Note 1). The second is acute rejection, which involves cell-mediated immunity (Note 2). The third is chronic rejection, which is said to be mainly due to the effects of humoral immunity. They are rejection symptoms that develop within a day, one week to three months, and three months to one year after transplantation, respectively. In any case, it is caused by the immune response that results from the difference in the biological system between oneself and others.

HLA is involved in the first concern about hyperacute rejection of organ transplants. There are three types (Note 3), and it is estimated that all of these patterns will match one in four, even for siblings. In the case of complete strangers, there would be only one in a hundred to a thousand. In recent years, excellent immunosuppressive drugs have been developed, so that even transplants that do not match HLA can suppress rejection to some extent, but HLA matching is indispensable to reduce rejection as much as possible.

"But if science could create a biological clone for you, that would have a pretty bad aftertaste, wouldn't it? This is just an imagination, but if you grow it with minimal stimulation in the culture, it should have no self-awareness or memory. So maybe you don't feel like a brother or sister with a gene similar to yourself. But once you see the real thing, you'll feel sick after that because of disgust and ethical thoughts. "

However, Miyahara calmly overturned Kanzaki's dark image.

"Yeah. Mr. Kanzaki is unexpectedly weak.

From the appearance, I don't think you're a human being who can't eat meat when you see the slaughter site ... Well, anyway, my clone is not someone else. Logically, it's just me. Therefore, it seems that the aftertaste should not be much worse than the act of a person killing another person and robbing an organ. Ethically speaking, assuming that the cloner would die if the organs were not donated, there would be no other choice. In the analogy of slaughter, it's the same as eating the meat you grow. "

"Even though the theory is so, it's not so easy to think about it."

"Sure, it's easy to say, but in reality there will be resistance."

After talking so far, they arrived in front of the conference room where Miyahara was heading. As expected, there is no sound leakage, but there are signs of people inside.

"Then, let's finish today," Miyahara said.

"I'm supposed to finish my work next week, so let's go drink at that time."

"Then, looking forward to that day, I will return to AD training."

Kanzaki made an effort to respond to Miyahara with a cheerful voice, bowed, and then ran away in the original direction. It seems that the colleagues other than Miyahara were already in the meeting room, and there were no other figures in the corridor.

After looking at the rear view of his young friend for a while, Miyahara tightened his mind and opened the door of the conference room.

Note 1

HLA = human leukocyte antigen / tissue-compatible antigen. Humoral immunity with HLA antibody. Humoral immunity is an immune system centered on antibodies and complements, and is so called because the antibodies are dissolved in serum. Also known as humoral immunity.

「いえ、ちょっとわかりかねます」と神崎。「ＳＦ小説の話ならばクローンかな、っていう気はしますけど」

　宮原は神崎には直接関係ないと言ったが、実は臓器売買と若年売春には関係がある。異常勃起目的でホルモン剤を多量投与され、その結果、低血圧／心疾患／脳梗塞といった副作用で使い物にならなくなった子供たち、あるいは売春宿オーナーの命令を聞かなかった子供たちの中には臓器の提供者（ドナー）として命を奪われる者もいる。日本を含め、先進国の金持ちの命を救うため、売買目的で臓器を抜かれ、最終的に死に至らしめられるというわけだ。その実態は正確には把握されていないが、現地で逮捕者が後を絶たないところをみると、危険だが労せず金を稼げる美味い闇商売なのだろう。人は利に傾く。そして被害を蒙るのはいつも社会的弱者だ。

「そうだな。確かにクローンだったら本質的に自分と同じ身体だから拒絶反応はないだろう」

　倫理的問題が伴うため、技術的には可能でも行政的には実行困難な生体クローン移植を社会に適応させるには、おそらく法律が必要だ。そして生体クローンを強制的に移植臓器として利用することが可能にならない限り――子供たちばかりでなく――貧困者の悲劇が続くだろう。そう考えると宮原は絶望的な気持ちに囚われてしまう。

「そうか、クローンならばな」

　宮原が神崎の言葉を受け、パチンと頭のスイッチを切り替える。

「可能性はあるな」

　臓器移植における拒絶反応には大きく分けて三つある。

　その一つが超急性拒絶で、これは主に提供者のＨＬＡ（註１）が関与する。二つ目が急性拒絶で、こちらは細胞性免疫（註２）が関係する。そして三つ目が慢性拒絶で、これは液性免疫の影響が主要因といわれている。それぞれ移植後、一日以内、一週間から三ヶ月、三ヶ月から一年以降に発症する拒絶症状だ。いずれにしても自分と他者との生体系の違いから起こる免疫反応が原因なのだ。

　臓器移植に関し、最初に懸念される超急性拒絶にはＨＬＡが関与するが、それには三種類（註３）あり、そのパタンすべてが一致するのは兄弟姉妹でも四人に一人、それ以外の赤の他人となると百人から千人に一人くらいしかいないだろうと見積もられている。

　近年では優れた免疫抑制薬が開発されているのでＨＬＡが合致しない移植でもある程度拒絶反応が抑制できるようになったが、そうはいっても拒絶反応をできるだけ少なくするにはＨＬＡの一致が不可欠なのだ。

「……ですけど自分用の生体クローンが実現できたとして、それはそれで結構後味悪いんじゃないですかね？　これは単なる想像ですが、培養液の中で最低限の刺激しか与えないように育てれば自己の認識も記憶もないでしょうから、たぶん自分の遺伝子を分けた兄弟姉妹という感じはしないかもしれませんが、でも一度でも実物を見たら、その先は嫌悪感と倫理的な想いの板挟みで気分が悪くなりますよ」

　だが神崎のそんな暗澹としたイメージを宮原は平然と引っ繰り返す。

「ふうん。神崎くんは案外気が弱いんだな。見かけからして屠畜現場を見たら肉が食べられなくなる人間とも思えんが……。まあ、それはともかく、自分のクローンは他人じゃなくてどこまでも自分なのだから、他人を殺して臓器を奪ったりするよりは、よほど後味が悪くないと思えるよ。倫理的に言っても臓器が提供されなければクローン元が死ぬと仮定すれば、他に選択の余地はないだろう。屠畜の喩えでいえば、自分が育てた肉を自分で喰うのと同じ理屈だ」

「理屈はそうでも、そんなに簡単に割り切れませんよ」

「確かにね。言うのは簡単だが、実際には抵抗があるだろうな」

　そこまで話したところで二人が宮原の目指す会議室前に到着する。さすがに音漏れはないが、中に人の気配がする。

「じゃ、今日はここで」と宮原。「来週中には仕事も一段落するはずだから、そのときは飲みに行こうじゃないか」

「では、その日を楽しみにＡＤ修行に戻るとします」

　神崎は努めて明るい声で宮原にそう応えると一礼して踵を返し、元来た方向に駆け足で去る。宮原以外の仕事仲間たちは既に会議室内にいるらしく廊下に他の人影はない。

　若い友人の後姿を暫しぼんやりと眺めた後、宮原は気を引き締め、会議室のドアを開ける。

　註１　ＨＬＡ＝ヒト白血球抗原／組織適合抗原。ＨＬＡ抗体による液性免疫のこと。液性免疫とは抗体や補体を中心とした免疫系で抗体が血清中に溶解して存在するため、こう呼ばれる。別名、体液性免疫。

　註２　獲得免疫のひとつで抗体が関与しない免疫系。マクロファージなどの免疫細胞が体内の異物を排除する。

　註３　ＨＬＡ・Ａ、ＨＬＡ･Ｂ、ＨＬＡ･ＤＲの三種類。なおヒトは各ＨＬＡを二種類ずつ持っているので実際には計六種類となる。