Q. On doing the kidney needle biopsy, lupus was confirmed but the blood shows sero negative. What is sero negative lupus? My doctor has already put me on immunosuppressors from the past few months. What is the future of my disease?
Lupus erythematosus (LE) is a chronic autoimmune inflammatory disease that can affect various parts of the body, especially the skin, joints, blood, and kidneys. Normally, the body's immune system makes proteins (antibodies) to protect us against viruses, bacteria, and other foreign materials (antigens). In an autoimmune disease the immune system loses its ability to tell the difference between foreign antigens and its own antigens (cells and tissues) and starts making antibodies directed against "self" antigens. These "auto-antibodies," react with the body’s tissues leading to inflammation and injury. There are three types of lupus: discoid (limited to the skin), systemic (affecting almost any organ system of the body), and drug-induced (occurring after the use of certain prescribed drugs).
There is no single laboratory test to diagnose this condition and a set of criteria has been described for its diagnosis. An individual needs to have four or more of these symptoms (not all occurring at the same time) to suspect lupus. Commonly used blood tests for diagnosis include: Anti-nuclear antibody test (ANA) to determine autoantibodies to cell nuclei; Anti-DNA antibody test to determine if there are antibodies to the genetic material in the cell; Anti-Sm antibody test to determine if there are antibodies to a ribonucleoprotein found in the cell nucleus; Serum complement estimation to determine the total level of a group of proteins which can be consumed in immune reactions and determination of Complement proteins C3 and C4.
Lupus nephritis is one of the most serious manifestations of SLE and is usually seen within 5 years of diagnosis. Generally, an elevated ESR & anti-dsDNA and low C3 and C4 levels are associated with active nephritis but there are instances where serological markers may be initially absent, and in many cases become positive after sometime. Renal biopsy, however, will show histopathological changes consistent with lupus nephritis in most patients even if they do not have clinical manifestations of renal disease. The symptoms are generally related to hypertension, proteinuria, and renal failure. A WHO classification system is used which is based on light microscopy, immunofluorescence, and electron microscopy findings from renal biopsy specimens. This grades the lesion from Class I to VI. The main aim of treatment is to normalize renal function or try to prevent the progressive loss of renal function and it differs depending on the pathologic lesion (class I lesions require no specific therapy while class VI need dialysis and kidney transplantation). Poor prognostic markers include: Young age of patient, male gender, delay in treatment of more than 5 months from onset of nephritis, hypertension, nephrotic syndrome, elevated creatinine level (>3 mg/dL) at presentation, persistently elevated anti-dsDNA and low C3 and C4 levels and renal biopsy showing diffuse proliferative glomerulonephritis or high chronicity index.