Main features of granulomatous-lymphocytic interstitial lung disease (GLILD) and sarcoidosis
| Main features | GLILD | Sarcoidosis |
| Gamma globulin | Generally decreased (may be normal in IgG subclass deficiency), low serum IgA level and higher IgM levels have been reported | Normal or increased, no specific Ig class or subclass level alteration |
| ACE | Generally normal | Often increased |
| Decreased circulating switched-memory B-cells | Frequent | Not reported |
| Increased circulating CD21 low B-cells | Frequent | Not found |
| BALF lymphocytosis | Frequent (>20%) | Frequent |
| Elevated BALF CD4:CD8 ratio | Reported in a small case series | Typical in acute Lofgren Syndrome |
| Recurrent infections | Generally reported | Infrequent |
| Autoimmune cytopenia | Frequent | Not associated, cytopenia may be due to bone marrow granulomatous infiltration or splenomegaly |
| Splenomegaly | Frequent | Spleen may be involved, splenomegaly is infrequent and generally secondary to severe liver disease |
| Nodular regenerative hyperplasia of the liver | Increased likelihood | Liver involvement is often asymptomatic, biopsies may show granulomatous hepatitis |
| Gastrointestinal involvement | Reported in 15% | Rare |
| Eye involvement | Not reported | Frequent |
| PLH histological and radiological evidence (e.g. LIP and FB) | Typical | Not present |
| Hilar adenopathy | May be present | Typical feature |
| Lung nodules size and distribution on HRCT | Often >1 cm, with random or predominantly basal distribution | Typically <1 cm, with mainly apical and peri-lymphatic distribution |
| Bronchiectasis | Frequent | Traction bronchiectasis may be found in advanced fibrotic disease |
| Prognosis | Slowly progressing restrictive lung disease with poor prognosis | Generally good prognosis, spontaneous remission may frequently occur, particularly in acute (Lofgren Syndrome) presentation |
ACE: angiotensin converting enzyme; BALF: bronchoalveolar lavage fluid; PLH: pulmonary lymphoid hyperplasia; LIP: lymphocytic interstitial pneumonia; FB: follicular bronchiolitis; HRCT: high-resolution computed tomography; Ig: immunoglobulin. Data from [16, 105, 106].