核周型抗嗜中性球細胞質抗體與感染之關聯性

Association between perinuclear antineutrophil cytoplasmic antibodies and infection: a retrospective study

目的：核周型抗嗜中性球細胞質抗體（perinuclear antineutrophil cytoplasmic antibody, p-ANCA）常作為診斷血管炎的依據。核周型抗嗜中性球細胞質抗體有時也會出現在受感染病人的血液中。經由回朔分析，探討核周型抗嗜中性球細胞質抗體及感染的關係。方法：選擇2006年至2010年之間，p-ANCA陽性的病人118位，及隨機選擇1173位p-ANCA陰性病人中的118位，將p-ANCA的陽性與否分為兩組，經由病例記錄及住院病程做回朔性分析。結果：44位（37.3%）p-ANCA陽性及14位（11.9%）p-ANCA陰性的病人有感染情形。在44位p-ANCA陽性合併感染的病人中,分別有36位（81.8%）受到Staphylococcus aureus的感染，15位（34.1%）受到multidrug resistant gram-negative bacterial感染，及21位（47.7%）受到Pseudomonas aeruginosa感染。在14位p-ANCA陰性合併感染的病人中，分別有6位（42.9%）受到Staphylococcus aureus感染，4位（28.6%）受到multidrug resistant gram-negative bacterial感染，及5位（35.7%）受到Pseudomonas aeruginosa感染。21位（17.8%）p-ANCA陽性病人及7位（5.9%）p-ANCA陰性病人被診斷為血管炎。37位（31.4%）p-ANCA陽性病人及16位（13.8%）p-ANCA陰性病人住進加護病房。結論：p-ANCA與感染之間有顯著的關聯性，且嚴重的感染可能引起p-ANCA的產生，特別是在加護病房的病人。對於p-ANCA陽性的病人，除了血管炎之外，還應該徹底的探查其潛藏著感染的可能性。

Background & objectives: Antineutrophil cytoplasmic antibody (ANCA) is often used in laboratory tests to confirm paucicellular vasculitis. However, ANCA is also occasionally found in patients with infectious disorders independent of any vasculitic process. We retrospectively studied the association between perinuclear antineutrophil cytoplasmic antibody (p-ANCA) and clinical conditions, especially infectious diseases. Methods: Between 2007 and 2010, 1291 patients (118 p-ANCA-positive and 1173 p-ANCA-negative patients) were tested for ANCA. We selected the total 118 p-ANCA-positive patients, and selected 118 of the 1173 p-ANCA-negative patients randomly. They were divided into 2 equal groups according to the presence or absence of p-ANCA. Data on their medical history and hospitalization course were retrospectively analyzed using their medical records. Results: Overall, 44 p-ANCA-positive patients (37.3%) and 14 p-ANCA-negative patients (11.9%) had infections. From the former group, 36 patients (81.8%) had Staphylococcus aureus infection, 15 (34.1%) had multidrug resistant gram-negative bacterial infection, and 21 (47.7%) had Pseudomonas aeruginosa infection. Of the latter group, 6 patients (42.9%) had Staphylococcus aureus infection, 4 (28.6%) had multidrug resistant gram-negative bacterial infection, and 5 (35.7%) had Pseudomonas aeruginosa infection. Further, 21 p-ANCA-positive patients (17.8%) and 7 p-ANCA-negative patients (5.9%) were diagnosed with vasculitis. Lastly, 37 p-ANCA-positive patients (31.4%) and 16 p-ANCA-negative patients (13.8%) required intensive care unit admission. Conclusions: p-ANCA is significantly associated with some infections. Patients with severe infections may produce p-ANCA, especially those requiring ICU admission. Those who test positive for p-ANCA should be thoroughly investigated not only for vasculitis but also for infectious conditions.