Lab Tests for Diagnosis of Lupus Nephritis

Lupus Nephritis is inflammation of the kidneys caused by Systemic Lupus Erythematosus (SLE). SLE is an autoimmune disease. The body’s immune system produces antibodies to target at its own body tissues. Lupus Nephritis occurs when kidneys are involved in by lupus. Lab tests for diagnosis of Lupus Nephritis mainly include antibody test, kidney damage test and kidney function examination.

Antibody test for diagnosis of Lupus Nephritis. Various types of auto-antibodies played key role in occurence of Lupus. Antibody-antigen immune complex deposition on renal tissues impair kidney functions and cause clinical symptoms such as swelling, hematuria, proteinuria, etc. Common antibody tests mainly include the follows:

*Anti-double stranded DNA test

*Anti-nucleosome antibody

*Anti-Sm antibody

*Anti-RNP antibody

*Anti SS-A antibody

*Anti SSB antibody

*Anti ribosomal antibody

*Anti-histone antibody

*Ant-PCNA antibody

*Anti-glomerular basement membrane antibody

*Anti-thyroglobulin antibody

*Antithyroid microsomal antibody

*Antibody tests, including antinuclear antibody (ANA) panel

Tests for identification of kidney damage. Purposes of the examinations mainly include confirming whether the kidneys have been damaged, the damaged part of kidneys, degree of kidney damage, etc.

1. Tests to confirm glomerular damage:

*Urine total protein test

*Microalbuminuria

*Urine IgG

2. Tests to diagnose impaired renal tubular damage

*Urine a1 microglobulin

*Urine GGT

*Urine NAG

*Urine osmotic pressure test

Kidney function test:

1.Glomerular filtration rate:

Glomerular filtration rate is the most effective value to reflect how well the kidneys are working. Normal range of GFR 100-140ml/min. Chronic kidney disease is divided by GFR range. A patient with ESRD has GFR<15.

2. Serum creatinine. A creatinine blood test (also known as a serum creatinine test) measures the blood's percentage of creatinine, a product of the breakdown of creatine. Creatinine is filtrated freely by the kidneys. If there is an elevated amount of creatinine in your blood, it can mean that your kidney's filtration system is malfunctioning.

3. Blood urea nitrogen

The blood urea nitrogen test (BUN) is done to determine the amount of urea nitrogen in the blood. Urea nitrogen, the byproduct of protein breakdown, is generally filtered out by the kidneys and used to make urine. Similar to creatinine, an elevated level of urea in blood indicates reduced renal filtration function.