These deposits take on characteristic shapes, depending on the variant under which they are said to occur: granular osmophilic deposits (GRODs) are generally characteristic of INCL, while curvilinear profiles, fingerprint profiles, and mixed-type inclusions are typically found in LINCL, JNCL, and ANCL, respectively. Electroencephalogram or EEG: An EEG uses special patches placed on the scalp to record electrical currents inside the brain. This helps doctors see telltale patterns in the brains electrical activity that suggest a patient has seizures. Electrical studies of the eyes: These tests, which include visual-evoked responses and electroretinograms, can detect various eye problems common in childhood NCLs. Brain scans: Imaging can help doctors look for changes in the brains appearance. The most commonly used imaging technique is computed tomography (CT), which uses x-rays and a computer to create a sophisticated picture of the brains tissues and structures. A CT scan may reveal brain areas that are decaying in NCL patients. An increasingly common tool is magnetic resonance imaging, which uses a combination of magnetic fields and radio waves, instead of radiation, to create a picture of the brain. Enzyme assay: A recent development in diagnosis of NCL is the use of enzyme assays that look for specific missing lysosomal enzymes for infantile and late infantile versions only. This is a quick and easy diagnostic test.
All pathways culminate in the production of a C3 convertase, which catalyses C3 into its constitutive parts (better detailed here – classical complement pathway).In brief, the crucial role of C1q in the pathway is its importance as the first protein to start the complement cascade (which ends in the destruction of the invading bacteria or virus), and its ability to link the two important arms of the immune system – the innate immune system: a broad defence system; and the adaptive immune system: the strong immune response capable of remembering previous infections, allowing fast response against recurrent infections, meaning that people with a normal immune system dont continually catch the same cold or same strain of flu repeatedly.Case studies of individuals with HUV have also highlighted other potential complicating factors which it seems the anti-C1q antibodies play a role in. This can mean in some cases the deposition of large immune complexes in the kidney which cannot be cleared by the usual cells of the immune system (e.g. macrophages which are unable to bind the Fc portion of the C1q antibody), leading to further complications. This seems to be rare, but can occur when a pre-existing renal condition is apparent. Also, there has been some speculation as to an additional autoantibody against an inhibitor protein (in the complement pathway) named C1-inhibitor. The inhibition of C1-inhibitor leads to over-activation of the complement pathway and one protein that builds up controls angioedema (vessel – swelling), resulting in excess water building up under the skin (the weal appearance).