Table 2. Likely cause of secondary antibody deficiency in each subject.
| SECONDARY | PROBABLE SECONDARY | |
| UNTREATED MALIGNANCY | 3 | - |
| CLL | 1 | - |
| MM | 1 | - |
| MGUS | 1 | - |
| CHEMOTHERAPY | 11 | 1 |
| with RTX | 9 | 1 |
| with stem cell transplant | 4 | - |
| CORTICOSTEROIDS FOR ASTHMA OR COPD | 6 | 5 |
| AUTOIMMUNE OR RHEUMATIC | 5 | 3 |
| RA or SLE | 2 | 2 |
| Wegener's granulomatosis | 1 | - |
| RA/SLE with RTX | 1 | 1 |
| SLE/Sjogren's with RTX | 1 | - |
| OTHER | 1 | 4 |
| Hepatitis C infection | 1 | - |
| Previous anti-convulsant drugs | - | 3 |
| Previous immunosuppressive drugs | - | 1 |
CLL indicates chronic lymphocytic leukaemia; MM, multiple myeloma; MGUS, monoclonal gammopathy of unknown significance; RTX, Rituximab; RA, rheumatoid arthritis; and SLE, systemic lupus erythematosus.