Università Vita-Salute San Raffaele, IRCCS San Raffaele Scientific Institute.
Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR), IRCCS San Raffaele Scientific Institute.
Rheumatology (Oxford). 2020 Sep 1;59(9):2435-2442. doi: 10.1093/rheumatology/keaa221.
Four clinical phenotypes of IgG4-related disease (IgG4-RD) have been recently identified by latent class analysis (LCA): pancreato-biliary (group 1); retroperitoneum/aortitis (group 2); head and neck limited (group 3); and Mikulicz/systemic (group 4). The reproducibility of this classification in clinical practice and its relevance for patient management, however, remain unknown.
The study included 179 patients. Four IgG4-RD experts were asked to classify a validation cohort of 40 patients according to published LCA-derived phenotypes based on clinical judgement. Agreement between LCA and clinical clustering was calculated. To assess differences among disease phenotypes, the following variables were recorded on an additional 139 patients: serum IgG4 and IgE; inflammatory markers; eosinophils; plasmablasts; IgG4-RD responder index (RI); history of atopy, diabetes, osteoporosis, relapses and malignancy; cumulative dose of glucocorticoids; and use of rituximab.
Clinical judgement replicated LCA classification with strong agreement among IgG4-RD experts (κ = 0.841, P < 0.0005). At disease onset, group 1 showed the highest levels of serum IgG4 and IgE. Groups 2 and 4 had the lowest and highest IgG4-RD RI, respectively. At 2 years' follow-up, group 3 received the highest cumulative dose of glucocorticoids, but higher incidences of diabetes mellitus were observed in groups 1 and 4, consistent with the higher likelihood of pancreatic involvement in groups 1 and 4. No difference among the four groups was observed in terms of disease recurrence, time to relapse and frequency of rituximab infusion.
Clinical phenotypes of IgG4-RD reflect differences in epidemiological features and prognostic outcomes.
通过潜在类别分析（LCA），最近确定了 IgG4 相关疾病（IgG4-RD）的四种临床表型：胰胆管（第 1 组）；腹膜后/大动脉炎（第 2 组）；头颈部局限性（第 3 组）；Mikulicz/全身性（第 4 组）。然而，这种分类在临床实践中的可重复性及其对患者管理的相关性尚不清楚。
本研究纳入了 179 例患者。根据发表的 LCA 衍生表型，由 4 名 IgG4-RD 专家根据临床判断对验证队列的 40 例患者进行分类。计算 LCA 和临床聚类之间的一致性。为了评估疾病表型之间的差异，在另外 139 例患者中记录了以下变量：血清 IgG4 和 IgE；炎症标志物；嗜酸性粒细胞；浆母细胞；IgG4-RD 反应指数（RI）；特应性、糖尿病、骨质疏松、复发和恶性肿瘤史；累积糖皮质激素剂量；以及利妥昔单抗的使用。
临床判断复制了 LCA 分类，IgG4-RD 专家之间具有很强的一致性（κ=0.841，P<0.0005）。在疾病发病时，第 1 组显示出最高的血清 IgG4 和 IgE 水平。第 2 组和第 4 组的 IgG4-RD RI 最低和最高，分别。在 2 年的随访中，第 3 组接受了最高累积剂量的糖皮质激素，但第 1 组和第 4 组发生糖尿病的比例更高，这与第 1 组和第 4 组胰腺受累的可能性更高一致。在疾病复发、复发时间和利妥昔单抗输注频率方面，四组之间无差异。
IgG4-RD 的临床表型反映了流行病学特征和预后结局的差异。
