다형핵백혈구의 탐식능에 관한 연구

Abstract

[한글]

감염에 대한 인체의 방어기전에는 여러가지 요소가 관여하나 그 중에서도 단핵성식세포(mononuclear phagocyte)와 다형핵백혈구(polymorphonuclear leukocyte)에 의한 세균 탐식작용은 매우 중요한 요소의 하나이다. 다형핵백혈구의 탐식능을 시험하기 위한 방법으로 Acridine orange-crystal violet (AO-CV) microassay법이 발표되었으나 이에 대한 추시가 보고된 바 없다.

이에 저자는 건강성인 52명에서 얻은 말초혈액 다형핵백혈구의 Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, 및 Pseudomonas aeruginosa에 대한 탐식능검사를 AO-CV microassay법으로 시도하여 다음과 같은 결과를 얻었다.

1. AO-CV microassay법에 의한 백혈구 탐식능검사에서 다형핵백혈구가 섭취 (ingestion)한 평균 균수는 45분과 60분 경과 후에 가장 많았다.

2. 건강성인의 다형핵백혈구의 E. coli에 대한 식작용(phagocytosis)은 97.6%, 식세포지수(phagocytic index)는 4.5, 세포내 살균작용(intracellular bactericidal activity)은 68.7%이었으며 공혈자의 성별 및 연령별에 따른 차이는 없었다.

3. 다형핵백혈구의 탐식능은 동일균종의 시험세균을 쓸 때 항생제 감수성 여부에 따른차이는 없었다.

4. 다형핵백혈구의 탐식능은 E. coli를 기준으로 할 때 P. aeruginosa에 대하여는 식작용과 식세포 지수가 낮았고 K. pneumoniae와 P. aeruginosa에 대하여는 세포내 살균작용이 낮았다.

이상의 결과를 종합하여 볼 때 본 AO-CV microssay법에 있어서 그 탐식능의 판독은 45분 및 60분 후에 할 것이며, 그 참고치 설정에는 성별이나 연령을 고려할 필요가 없으며, 시험세균에 관하여는 항생제 감수성과는 상관없다는 결과를 얻었다. 또한 이 방법은 매우 간단하며 단시간내에 시험할 수 있으므로 여러가지 방어기전의 저하를 의심하는 환자의 진단을 위한 통상검사로서 적당하며, 또한 균종에 따라 같은 사람의 다형핵백혈구도탐식능의 차이를 보임으로 백혈구 수혈을 고려할 때 보조적인 검사방법이 될 것으로 생각된다.

[영문]

Among the various factors involving in host defense mechanism against infections, the phagocytic activities of mononuclear phagocytes and polymorphonuclear leukocytes (PMNs) are the important ones. Recently a microassay using acridine orange and crystal violet(AO-CV) was proposed as a promising technique to access the phagocytic activities of PMNs. However, there has been no thorough reevaluation on this method.

The author intended to study the practicability of the technique in clinical laboratories. Peripheral bloods of 52 healthy adults and Escherichia coli, Klebsiella pneumoniae, Serratia marcescens and Pseudomonas aeruginosa were used in

the study. Particular attention was paid to the difference of phagocytic activities of PMNs by the bacterial species.

The following results were obtained.

1. When E. coli was used as the test organism the average number of ingested bacteria by PMNs was greatest at 45 and 60 minutes.

2. Calculated values of phagocytic activities by Pruzanski's method(1983) were as follows, when E. coli was used as test organism: Percent of phagocytosis: 97.6%; phagocytic index: 4.5; intracellular bactericidal activity: 68.7%, There was no difference of these values by the sex or age of PMN donors.

3. There was no difference of phagocytic activities by the difference of antimicrobial susceptibilities of the test organism provided the same species were used through out the study.

4. The precentage of phagocytosis and phagocytic index were decreased when P. aeruginose was used as test organism instead of E. coli and the intracellular bactericidal activity was decreased when both K. pneumoniae and P. aeruginosa were used instead of E. coli.

In view of the above results, it can be said that the proper reading time of the AO-CV metaod would be both at 45 and 60 minutes and in setting the reference values of phagocytic activities no consideration as to sex or age would be necessary.

Furthermore, as to the test organism the antimicrobial susceptibility has no correlation with the phagocytic activities. Also, it was provon that the AO-CV technique is simple and fast enough to perform in a clinical laboratory, and since the same individual's PMNs reveal different phagocytic activities by the test organism, it could be used to evaluate the feasibility of PMN transfusion to those immunologically compromized patients.