WE ALL HAVE!!! Protein in the urine is one of the indicators of kidney involvement in Lupus. Kidney involvement in lupus rarely causes discomfort or pain (as distinct, for example, from kidney stones or infection). The most common major kidney problem is that of protein leakage in the urine. This can be mild and detected only on testing, or severe gradually leading to a lowering of the protein level in the blood (a low albumin level). When this happens there is a tendency to ankle swelling, to fluid retention and to general fluid bloating. When the kidney is inflamed the blood pressure frequently rises and blood pressure measurement is one of the important parts of the physical examination of lupus patients. When the kidney is more severely damaged, its normal filtering process is grossly impaired and toxic elements such as urea and creatinine, normally present in the blood in small amounts, build up leading to weight loss, nausea and a general feeling of being sick all of the time.
If the lupus patient is losing protein in the urine ('proteinuria') then the amount of protein leakage may need to be quantified. For this a 24-hour urine preparation is required. All the urine over a full 24-hour period is collected and the precise amount of protein lost over this period is measured. For other urine constituents the sample is sent to the laboratory for analysis for bacteria and for microscopic examination. Normal urine under the microscope is clear but when there is inflammation anywhere in the urinary tract (in the kidneys or the bladder) cells are present, either red cells or white cells. More important is the presence of clumps of cells called 'casts'. These clumps - looking rather like a railway train of goods wagons - is indicative of kidney inflammation rather than bladder inflammation and is of vital importance in the diagnosis and assessment of the kidney.
Much information concerning kidney function is also obtained from blood tests. The three main blood tests affected by kidney function are the blood urea (sometimes called blood urea nitrogen or BUN), the creatinine and the albumin. If the vital filtering function of the kidney is impaired then urea and creatinine levels start to rise and these two measurements are the most important guides to the severity of kidney involvement. The blood level of albumin (protein) falls if leakage of the protein in the urine is present.
When there is kidney inflammation, a combination of steroids and an immunosuppressive medicine will probably be prescribed. For active or severe kidney disease, the most widely used immunosuppressive is cyclophosphamide given intermittently by injection. In the olden days cyclophosphamide was given as a tablet but this produced more side-effects and most units have now converted to giving intermittent 'pulses'. This comes in the form of a drip given into the vein, usually given weekly for three weeks then monthly for 3-12 months. Doses vary from clinic to clinic but the more modern fashion has been to use lower doses than those previously used and this has the benefit of far less side-effects.
A milder and very widely used immunosuppressive is azathioprine given as tablet-form usually at a dose of about 2’mg/kg body weight. All immunosuppressives can affect the blood count and regular blood counts are going to be mandatory.
Other immunosuppressive drugs such as cyclosporin-A are increasingly used but the two mainstays of treatment remain cyclophosphamide and azathioprine.
I hope that this information has been helpful to you. I wish you the best!
Peace and Blessings