상부와 하부 요로감염에서 뇨 β2-microglobulin치의 의의

Abstract

[한글]

β^^2-microglobulin(β^^2-M)은 무게 11,800 dalton의 저분자량 단백으로, 모든 유핵세포에서 생성되어 세포막에 존재하며, 대사는 신장에서 이루어진다. β^^2-M은 분자량이 작아 신사구체를 잘 통과하며 거의 대부분 근위세뇨관에서 재흡수되어 대사되므로, 신세뇨관 장애가 있을 경우 β^^2-M의 재흡수율이 감소되어 뇨중 배설량이 증가하게 된다. 감염 부위를 감별하기 어려운 소아 요로감염에서, 상부 요로감염은 신장 실질 특히 근위세뇨관의 손상이 있으므로 하부 요로감염에 비해 β^^2-M의 뇨 배설량이 증가하게 된다.

이에 저자는 24 hr 뇨 β^^2-M치와 β^^2 -M제거율 및 혈청 β^^2-M치를 측정하여 소아에서의 상부와 하부 요로감염을 감별하고자, 1987년 11월부터 1988년 7월까지 9개월간 연세대학교 의과대하 세브란스병원 소아과에 입원했던 요로감염 환아 23례, 대조군 7례를

대상으로 본 연구를 시행하였다.

상부 요로감염에서 혈청 β^^2-M치는 3.27±2.79mg/ℓ, 뇨 β^^2-M치는 3.74±7.89mg/24hr으로 대조군 (2.01±0.82 mg/ℓ, 0.08±0.05 mg/24 hr) 및 하부 요로감염 (1.83±0.41mg/ℓ, 0.08±0.05 mg/24hr)에 비해 유의하게 증가되었다.

이상의 결과로 요로감염 환아에서 혈청과 뇨중 β^^2-M치의 측정은 상부 및 하부 요로감염을 감별하는데 비침습적이고 매우 유용한 방법이라고 할 수 있다.

[영문]

β^^2-micloglobulin is a small protein with a molecular weight of 11,800 dalton. It is synthesized by most nucleated cells, and is present on their surfaces. It passes easily through the glomerular membrane and almost completely reabsorbed in the proximal tubules of the kidney where it is metabolized. Therefore

β^^2-microglobulin excretion is increased in disorders affecting the proximal tubules. Since there is tubular involvement in upper urinary tract infection, urinary excretion of β^^2-microglobulin is expected to increase in upper urinary tract infection.

To distinguish between upper and lower urinary tract infection, the author measured the urinary excretion and renal clearance of β^^2-microglobulin. The patients with upper urinary tract infection was 11 and the patients with lower urinary tract infection was 12, who were admitted at Severance Hospital, Yonsei

University College of Medicine from November 1987 to July 1998.

As a control, 7 healthy individual without renal disease, malignance and autoimmune disease were also investigated.

The results were as follows.

1. In patients with upper urinary tract infection, the serum β^^2-microglobulin level was 3.27±2.39 mg/l and the 24hr urinary excretion of β^^2-microglobulin was 3.74±7.89 mg/24hr, both of which were significantly increased over those of the

lower urinary tract infection (1.83±0.41 mg/l, 0.08±0.05 mg/24hr).

2. There was no overlap of β^^2-microglobulin excretion values between patients with upper urinary tract infection and those with lower urinary tract Iifection. From these results, it can be suggested that measurement of urinary excretion of β^^2-microglobulin is a non-invasive and specific method to distinguish between upper and lower urinary tract infection.