Immunology
The Division offered a series of specialised cellular immunological tests for the assessment of various immune deficiency disorders. Assays for immune deficiency analysis include lymphocyte enumeration and functions and the quantitation of lymphocytes and their subsets. These are performed using FACS analysis in collaboration with the Department of Haematology. In the assessment of neutrophil functions a variety of tests examine neutrophil chemotaxis, phagocytosis, intracellular killing ability, nitro-blue tetrazolium(NBT) reduction, phagosome-lysosome fusion and H2O2production. Assays for the detection of anti-neutrophil antibodies havebeen extended to identify the presenceof anti-neutrophil cytoplasmic antibodiesin the sera of neutropenic patients.
Routine services also include the assessment of cytokine production and the in vitro proliferative response to mitogens and antigens. In particular, the cytokines, interleukin-1, IL-10, IFN-gamma, GM CSF and TNF could bedetected in the sera of patients. The analysis of in vitro cytokine production can also be undertaken.
Immunoglobulin G (IgG) subclass (IgG 1-4) level determinations are offered for assistance in the diagnosis of chronic viral or bacterial infections.
Tissue typing on patients with a variety of diseases, as well as those awaiting transplants, and in disputed paternity cases is performed daily as a standard service, as is the screening for preformed antibodies andcross-match analysis for patients awaiting organ or bone-marrow transplants.
For the detection of anti-mycobacterial antibodies and mycobacterial antigens in various body fluids, ELISA s are used in the screening for tuberculosis. The ELISA s offered are for the detection of anti-M.tuberculosis antibodies in serum and for mycobacterial antigens in body fluids such as pleural, ascitic and cerebrospinal fluids.
As an essential component for identifying allergy to a large numberof different allergens, RASTs are performed on patients sera. In recent months we have increased the service offered for all tests to determine allergy, a wider selection of tests for aero allergens and for food and drug allergies are now available. Furthermore, a comprehensive range oftests to detect specific IgE to various antibiotics, other than penicillin, is also now available. The drugs tested for include :- ampicillin; amoxycillin;cephalosporin; trimethoprin; tetracycline; erythromycin and gentamycin.
Conditions such as systemic lupus erythematosus, Raynaud's phenomenon,renal disease, hereditary angioedema or recurrent bacterial infections may be associated with depression or deficiency of certain complement proteins or with the presence of serum inhibitors of the system. Additional tests for complement activity therefore include the estimation of C1q, C3, C4,factor B and C6 by laser nephelometry, the determination of nephritic factorby a haemolytic assay and the detection of C1 esterase.
The Division offers a wide range of diagnostic tests for infectious diseases, as well as specialised investigations for the detection of autoimmune diseases and serum protein irregularities. A wide range of tests for the identification of autoimmune diseases are in routine use. These consist of IFA tests for the investigation of anti-nuclear antibodies/anti-nuclear factor (ANA/ANF) against smooth muscle, parietal cells, mitochondria and Hep-2 and antibodies to dsDNA, Smith antigen (SM), Scl70, Jo-1, RO, L ntigens. A test for ANA in dogs is also available. A range of methods are employed for the determination of anti-cardiolipin, anti-thyroid, anti-adrenal and anti-pancreatic antibodies and of rheumatoid factor.