VAAL TRIANGLE - Japan approved a blood test kit to diagnose Alzheimer's disease, its manufacturer announced on Thursday, a rare advance in tackling a condition that affects tens of millions worldwide. EWN reports Sysmex Corporation said it was now working to get the kit, which measures the accumulation of a protein that is a marker for the disease, to market as soon as possible. Existing methods of diagnosing Alzheimer's are expensive and medically intrusive, often involving a brain scan or spinal tap. The Alzheimer's Association, a United States-based group, said in a statement an urgent need exists for simple, inexpensive, non-invasive and easily available diagnostic tools such as blood tests to diagnose the disease. In Alzheimer's disease, two key proteins, tau and amyloid beta, build up into tangles and plaques, known together as aggregates, which cause brain cells to die and lead to brain shrinkage.