IgG4-related respiratory disease

Figures & data

Figure 1. Chest CT scans of IgG4-RRD, showing. (a) Mediastinal lymphadenopathy. (b) Bronchial thickening in both upper lobes (white arrows), subpleural small consolidation in the left upper lobe (black arrow). (c) Interlobular thickening and infiltrative shadow in the right middle lobe (white arrowheads). (d) Mass-like consolidation in the left upper lobe. (e) Paravertebral thickening in the right lower lobe (white arrow).

Figure 2. Diagnostic algorithm.

CD: Castleman disease (plasma cell type); EGPA: eosinophilic granulomatosis with polyangiitis; SLE: systemic lupus erythematosus. *sclerosing dacryoadenitis・sialadenitis, autoimmune pancreatitis, IgG4-related sclerosing cholangitis, IgG4-related kidney disease, retroperitoneal fibrosis.

Reprinted permission from Reference [5].

Table 1. Summary of diagnostic criteria for IgG4-RRD.

1. Abnormal shadow on chest CT Hilar/mediastinal lymphadenopathy Thickening of bronchial wall, bronchovascular bundle, interlobular septal wall Nodular shadow, infiltrative shadow, pleural thickening/effusion

2. Elevated serum IgG4 concentration (≥135 mg/dl)

3. Pathological findings satisfying the following two items or more: (a: ≥3 items, b: 2 items) 1)Dense lymphoplasmacytic cell infiltration into respiratory organ tissues 2)IgG4+/IgG + cell ratio >40% and/or >10 IgG4+ cells/high power field 3)Obliterative phlebitis or obliterative arteritis 4)Characteristic fibrosis, typically storiform pattern

4. Presence of lesions in the extrathoracic organs satisfying the diagnostic criteria of IgG4-related disease 〈reference finding〉hypocomplementemia

Definite diagnosis (definite):1 + 2 + 3a, 1 + 2 + 3b + 4.

Probable diagnosis (probable):1 + 2 + 4, 1 + 2 + 3b + reference finding.

Possible diagnosis (possible):1 + 2 + 3b.

Table 2. Differential diagnosis for IgG4-RRD.

Multicentric Castleman disease (plasma cell type) GPA (Wegener granuloma) EGPA (Churg-Strauss syndrome) Sarcoidosis Lung cancer, malignant lymphoma Nonspecific interstitial pneumonia (idiopathic, collagen vascular disease-related) RDD Infection

Matsui S, Yamamoto H, Minamoto S, Waseda Y, Mishima M, Kubo K. Proposed diagnostic criteria for IgG4-related respiratory disease. Respir Investig. 2016;54(2):130–2.

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