Purple urine bag syndromeの臨床像に関する検討

Abstract

尿道カテーテルを継続留置している15症例(男14名, 女1名, 30～74歳)のうち紫色尿バッグ症候群(PUBS)を呈した5症例(全例男, 55～74歳)の尿所見・生化学所見・血中アミノ酸分析などを, PUBSを呈さない10症例(コントロール群)と比較検討した。尿検査ではPUBS全例で高度アルカリ尿を呈し, PUBS群pH8.5に対しコントロール群pH7.3と有意差を認めた。また, 血中アミノ酸分画ではα-aminobutyric acidがPUBS群16.2nmol/mlでコントロール群12.4nmol/mlより有意に高値であった。PUBS群において尿中インジカンは2例で検出され, 尿培養検査ではProvidenciae spp., Citrobactor spp., γ-Streptococcus, Proteus mirabilis, Serratia spp., Entero.faecalis, PS.aeruginosa, Morganella-morganiiが同定された。PUBSではアルカリ尿の存在が着色機序に関与している可能性が示唆された。

Purple urine bag syndrome (PUBS) occurs predominantly in chronically catheterized and constipated patients. This syndrome is associated with bacterial urinary tract infections that produce sulfatase or phosphatase. Tryptophan is converted to indole and indigo-producing bacteria have indoxyl phosphatase or sulfatase that can produce indigo (blue) and/or indirubin (red) in patients with urinary tract infection. To further explore the metabolism of these amino acids, we evaluated the serum levels of amino acids in patients with PUBS. A total of 15 patients were enrolled in this case-control study (PUBS-positive case group: 5 patients, PUBS-negative control group: 10 patients). Data from urine tests (pH, sugar, protein, leukocyte counts), renal functions (BUN, creatinine), serum levels of amino acids, and performance status were compared between the two groups. No significant differences were seen between the two groups in urine sugar, protein, leukocyte counts, renal functions, and performance status. The mean urine pH was significantly higher in PUBS patients than in control patients (8.5+/-0.0 vs. 7.3+/-1.16, respectively, p=0.0321), and serum levels of alpha-aminobutyric acid were significantly higher in PUBS patients than in control patients (16.2+/-3.08 vs. 12.4+/-3.20, respectively, p=0.0275). These data suggest that strong alkaline urine acts as an important factor in PUBS, in combination with other facilitating factors.