小児期発症全身性エリテマトーデスにおける二次性シェーグレン症候群合併の位置づけ  [in Japanese] Sjogren's syndrome associated with childhood-onset systemic lupus erythematosus  [in Japanese]

  小児期発症全身性エリテマトーデス（SLE）における二次性シェーグレン症候群（SS）合併の実態について検討した．SLE34症例（男児2例，女児32例，平均発症年齢11.5±2.6才）のうち，SS関連抗体である抗SS-A/Ro抗体またはSS-B/La抗体が陽性であった20例（58.8%）に対し，厚生省（旧）シェーグレン症候群1999年改定診断基準に基づき評価した．唾液腺および涙液腺の分泌機能検査はそれぞれ5/16例（31.3%），2/15例（13.3%），口唇小唾液腺生検所見は14/17例（82.4%）で陽性で，14例（SS関連抗体陽性症例の70.0%，全症例の41.2%）がSS併発と診断された．全例自覚的乾燥症状のない無症候性SSであった．またSLE単独群，SLE+SS併発群における発症時臨床像の比較では，SLE+SS併発群で血清IgG値が有意に高く，抗U1−RNP抗体も高頻度で認められた．臨床症状では全身倦怠感がSLE+SS併発群に多い傾向がみられた．腎炎はWHO III型以上の重症型がSLE単独群の35.7%に比べSLE+SS併発群では76.9%と有意に多くみられたが，SLE disease activity index (SLEDAI）は発症時，1年後，2年後のいずれも差を認めなかった．本邦では1999年改定診断基準が公表され，外分泌腺が破壊される前段階でのSS診断が可能となったが，将来的な乾燥症状や不定愁訴などの腺外症状の出現を念頭においた経過観察にとって有用な基準と考えられた．

  Sjögren syndrome (SS) is a common autoimmune disease that exhibits broad organ-specific and systemic manifestations, the most prevalent being decreased lacrimal and salivary gland function, xerostomia, and keratoconjunctivitis sicca. Secondary SS occurs associated with autoimmune diseases, most commonly systemic lupus erythematosus (SLE). Thirty-four childhood-onset SLE patients (2 boys and 32 girls, mean onset age 11.5±2.6 years) were evaluated for the presense of secondary SS using the classification criteria for SS revised by Japanese Ministry of Welfare in 1999. Clinical manifestations, selorogical findings, and renal pathology in SLE patients complicated with SS (SLE+SS, n=14) were compared with those in SLE with no SS autoantibodies (Ro/SS-A or La/SS-B) (SLE-no SS antibodies, n=14). Of all 34 cases, 20 (58.8%) were with positive Ro/SS-A or La/SS-B antibody. Fourteen of the 20 (70.0%) were diagnosed as having secondary SS and all of them were subclinical SS with no sicca symptoms. However, findings of Schirmer test, salivary flow test and minor salivary gland biopsy were positive in 2 of 16 (13.3%), 5 of 16 (31.3%), and 14 of 17 (82.4%) patients, respectively. Compared with the SLE-no SS antibodies group, patients with SLE+SS showed higher level of serum IgG and had higher frequency of anti-U1 RNP antibody and significantly more severe renal involvement. The revised criteria is useful for diagnosis of SS in early stage before the development of exocrine gland damage and appears to be helpful for long term follow-up in childhood-onset SLE associated with SS.