松果体部腫瘍におけるlymphoid cellの免疫学的意義

IMMUNOLOGIC SIGNIFICANCE OF LYMPHOID CELLS AGAINST PINEAL TUMORS IN MAN

I．はじめに

　松果体部に発生する腫瘍は，臨床的に特徴ある症状を呈する一方，組織学的にも極めて特徴ある像を呈するものである。two cell patternのpineal tumor^2,10）はその典型的なものであり，大型の明るい細胞を取り囲むように認められるlymphoid cellは，時にstroma様の形態を呈するものである。Marshall^6）らはその組織所見よりlymphoid cellがある種の免疫反応の結果として出現しているものであろうとの仮説を述べている。しかしながらこれらのlymphoid cellが，抗体産生細胞であるのか否か，さらにこの場で抗体を産生しているものなのかそれとも他の場所で作られた抗体をここに運んで来たものであるのか，また抗体を作つているとすれば如何なる種類の抗体を作つているのかといつた機能面に関する確証は何一つ明らかにされていないのが現状である。

　私共はこれらlymphoid cellの抗体産生に関する検索を行ない多少の知見を得たので報告する。

Pineal tumors are usually composed of two distinct cell types; large spheroidal cells and lym-phoid cells. In some cases, there is conspicuous granulomatous reaction including multinucleated giant cells mixed with infiltration of lymphocytes, plasma cells and histiocytes. It has been suggested that the reaction possibly represents an immunol-ogic one specific to this group of tumors. How-ever, this hypothesis has not yet been established. It remained unsolved whether the lymphoid cells produce the antibody and if so, what kind of antibody it is.

Surgically and autoptically excised materials from 3 patients with germinomas were examined. Small pieces of neoplasmic tissue were fixed in ethanol and embedded in paraffin. Thin sections were washed with cold phosphate buffer saline (PBS) and each of them was reacted with fluorescein iso-thiocyanate (FITC) labeled anti-human IgG, IgM and IgA rabbit γG. Surgically excised materials, 5 to 8% of lymphoid cells, were reacted with anti-human IgG conjugate but not with other conjugates.

After incubating the sections with serum of the patient at 37℃ for about 30 minutes, anti-human IgG conjugate stained either lymphoid cells or epithelioid cells, but other conjugates stained none of them. In these cases, the mitotic epithelioid cells and lymphoid cells reacted with anti-human IgG conjugate were stained with methylgreen-pyronin solution. While, these lymphoid cells were found rather in foci areas than in perivascular areas. Anti-human IgG conjugate reacting lym-phoid cells had been morphologically defined as the plasmacytic lymphocyte.

Thus we could prove the immunological signifi-cance of lymphoid cells against pineal tumors in man and get the following results;

1) The plasmacytic lymphocytes produce γG anti-body and these frequencies are calculated in 5 to 8% of the lymphoid cells.

2) These antibodies are synthesized in foci areas rather than in perivascular areas or others.

3) This γG antibody reacts specifically against in tumor.