Overview Severe combined immunodeficiency (SCID) is the most severe form of primary immunodeficiency, characterised by profound defects in both humoral (B-cell) and cellular (T-cell) immunity. It presents…

Overview Selective IgA deficiency is the most common primary immunodeficiency, defined by very low or absent serum IgA levels with normal levels of other immunoglobulins (IgG, IgM). Many patients are…

Overview Hyper-IgE syndrome (HIES) is a rare primary immunodeficiency characterised by markedly elevated serum IgE, recurrent staphylococcal skin and lung infections, eczema, and connective tissue/…

Overview Complement deficiencies are rare primary immunodeficiencies resulting from inherited absence or dysfunction of complement proteins, regulators, or receptors. They predispose to recurrent…

Overview Common Variable Immunodeficiency (CVID) is the most frequent clinically significant primary antibody deficiency, characterised by hypogammaglobulinaemia and impaired antibody responses. It…

Overview Chronic granulomatous disease (CGD) is a rare, inherited primary immunodeficiency characterised by defective function of the NADPH oxidase enzyme complex in phagocytes, leading to failure of the…

Overview Rheumatoid pleural effusion (RPE) is an uncommon extra‑articular manifestation of rheumatoid arthritis (RA), occurring in ~2–5% of patients, more often in middle‑aged men with high rheumatoid factor…

Overview Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a serious extra-articular manifestation of RA, affecting up to 10% of RA patients clinically, though subclinical involvement may…

Overview Sjögren’s-associated interstitial lung disease (Sjögren’s-ILD) is a significant extra-glandular manifestation of primary Sjögren’s disease (pSS), occurring in ~9–20% of patients clinically, with…

Overview Systemic sclerosis–associated interstitial lung disease (SSc-ILD) is one of the most common and severe internal organ manifestations of systemic sclerosis (SSc), occurring in up to 50–60% of patients…