特発性炎症性ミオパチーにおける筋炎特異的自己抗体と筋病理との関連

The association between myositis-specific autoantibodies and muscle pathologies in idiopathic inflammatory myopathies.

• Qiu Xu
• Qiu-Xiang Li
• Fang-Fang Bi
• Hui-Qian Duan
• Yue-Bei Luo
• Huan Yang

抄録

目的:

特発性炎症性ミオパチー(IIM)患者における異なる種類の筋特異的自己抗体(MSA)の特異的な筋病理を調べること。

OBJECTIVE: To investigate specific muscle pathologies of different kinds of myositis-specific autoantibodies (MSAs) in idiopathic inflammatory myopathy (IIM) patients.

方法:

欧州神経筋センター（ENMC）の基準によりIIMsと診断された中南大学仙雅病院の中国人患者111名を対象に、臨床症状、筋炎特異的自己抗体、組織学的所見、筋膜周囲萎縮、炎症細胞のパターンを検討した。臨床症状、筋炎特異的自己抗体、組織学的所見を評価し、異なるMSAを有するIIM患者の壊死、再生、筋膜周囲萎縮、炎症細胞のパターンを検討した。

METHODS: One hundred eleven Chinese patients from Xiangya Hospital, Central South University diagnosed with IIMs according to European Neuromuscular Centre (ENMC) criteria were included. Clinical manifestation, myositis-specific autoantibodies, and histologic findings were evaluated to explore the pattern of necrosis, regeneration, and perifascicular atrophy, inflammatory cells in IIM patients with different MSAs.

結果:

抗SRP群は筋力スコアが最も低く、クレアチンキナーゼ値が最も高く、壊死・再生の程度が最も重度（1.90[0.80～3.95]、1.00[0.30～1.71]）で、MHC-I染色陽性率が最も低い（35.71％）。抗MDA5群は最も軽度の病理学的変化を示し、壊死・再生筋線維が最も少なく（0.00[0.00-0.50]、0.00[0.00-0.00]）、炎症性細胞浸潤が最も少なく、筋力スコアが最も高い。抗NXP2群では、炎症性細胞浸潤が最も多く、特にCD4+ T細胞の浸潤が多い（31.14[15.00-39.00]）。抗NXP2抗体と抗TIF1γ抗体を持つ患者では、パンチアウト線維（1.50[0.00-3.70]、0.00[0.00-1.00]）と筋膜周囲萎縮（71.43％、55.56％）の頻度が高くなっています。抗シンテターゼ抗体（ASA）については、抗Jo-1抗体群が最も頻度の高い筋膜周囲壊死（60％）を示し、他のASA群では筋膜周囲壊死は認められなかった。

RESULTS: Anti-SRP group has the lowest muscle strength scores, the highest creatine kinase levels, the most severe degree of necrosis and regeneration (1.90[0.80-3.95], 1.00[0.30-1.71]), and the lowest positive rate of MHC-I staining (35.71%). The anti-MDA5 group demonstrates the mildest pathological changes, with the fewest necrotic and regenerated muscle fibers (0.00[0.00-0.50], 0.00[0.00-0.00]), and the fewest inflammatory cell infiltration, and the highest muscle strength scores. The anti-NXP2 group has the most frequent inflammatory infiltrates, especially CD4+ T cells (31.14[15.00-39.00]). The patients with anti-NXP2 and the anti-TIF1γ antibodies show higher frequency of punched-out fibers (1.50[0.00-3.70], 0.00[0.00-1.00]) and perifascicular atrophy (71.43%, 55.56%). As for anti-synthetase antibodies (ASAs), the anti-Jo-1 group shows the most frequent rate of perifascicular necrosis (60%), while other ASA groups do not show perifascicular necrosis.

結論:

その結果、抗SRP抗体は最も重篤な筋萎縮を示し、抗MAD5抗体は最も軽度であった。抗NXP2抗体と抗TIF1γ抗体群は、最も典型的な「DM」病理学的特徴を有する。抗SRP抗体群は重度の筋病理を示し、抗MDA5抗体群は最も軽度である。抗NXP2抗体群では、パウチアウト線維と筋膜周囲の萎縮がより多く見られます。

CONCLUSIONS: Of the MSAs, the anti-SRP antibody leads to the most severe muscle involvement, while the anti-MAD5 antibody the mildest. The anti-NXP2 and anti-TIF1γ groups have the most typical "DM" pathology. Key Points • Anti-SRP group shows severe muscle pathology while anti-MDA5 group shows the mildest. • Anti-NXP2 group has the most frequent inflammatory infiltrates. Pouch-out fibers and perifascicular atrophy are more prevalent in anti-NXP2 and anti-TIF1γ groups. • Anti-Jo-1 group is often accompanied by perifascicular necrosis, while other anti-synthetase antibody groups are not.