Summary of investigations performed, confirming alveolar haemorrhage and evaluating anti-GBM status
| Subject 1 | Subject 2 | Subject 3* | Subject 4* | |||
|---|---|---|---|---|---|---|
| Episode 1 | Episode 2 | Episode 1 | Episode 2 | Episode 3 | Episode 2 | |
| +, positive; −, negative; ND, not performed; Prot, protein; ELISA, enzyme linked immunosorbent assay; Kco, carbon monoxide transfer factor; GBM, glomerular basement membrane; ANCA, anti-neutrophil cytoplasmic antibodies; IIF, indirect immunofluorescence; MPO, myeloperoxidase; PR3, proteinase-3; Unint, uninterpretable. | ||||||
| Reference ranges for anti-GBM assays: Immunoblot = negative, ELISA <20 for both, IIF <1:2. | ||||||
| *Episode 1 for both subjects 3 and 4 predated involvement with the respiratory service (see text for details): anti-GBM antibodies at episode 1 were negative for subject 3 (immunoblot) and positive for subject 4 (ELISA). | ||||||
| †Radiology positive if demonstrated bilateral alveolar opacification consistent with alveolar haemorrhage. | ||||||
| ‡Bronchoscopy positive if consistent with alveolar haemorrhage—that is, progressively bloodier returns on sequential bronchoalveolar lavage ± numerous haemosiderin laden macrophages seen on cytological examination. | ||||||
| §Inova Slides (San Diego, USA) except subject 4 (performed on in-house cytospin slides). | ||||||
| ¶Orgentec (Mainz, Germany). | ||||||
| **Renal biopsy positive if linear immunofluorescent staining of glomerular basement membrane present. | ||||||
| Chest radiology† | + | + | + | + | + | + |
| Bronchoscopy‡ | + | ND | ND | + | ND | + |
| Kco (% predicted, corrected for Hb) | ND | 120% | 167% | 140% | 170% | 130% |
| Urinalysis | − | − | Prot trace | − | Prot 1+ | − |
| Blood 3+ | Blood 1+ | |||||
| Haemoglobin (g/l) | 154 | 86 | 94 | 122 | 92 | 102 |
| Serum creatinine (mmol/l) | 0.064 | 0.07 | 0.08 | 0.11 | 0.09 | 0.72 |
| ANCA | ||||||
| IIF§ | − | Unint | − | − | − | − |
| MPO/PR3 ELISA¶ | ND | − | − | − | − | − |
| Anti-GBM antibodies | ||||||
| Immunoblot (GBM QuickCard) | − | + | − | − | − | − |
| ELISA (Immco Diagnostics) | + | − | − | − | ||
| ELISA (Euro-Diagnostica) | − | − | − | |||
| IIF (The Binding Site) | − | − | ||||
| Renal biopsy** | ND | ND | + | ND | + | ND |