The Erythrocyte sedimentation rate test is used to determine inflammatory response in the body. Inflammation is part of the immune response system. The ESR is a useful test for diagnosing inflammation, infection, trauma or malignant disease. The ESR can act as important prognostic factor in non-inflammatory conditions, such as coronary heart disease, stroke, heart failure and prostate cancer. The Erythrocyte sedimentation rate test is a blood test that determines the speed at which erythrocytes, or red blood cells (RBCs), settle to the bottom of a test tube containing a blood sample. Red blood cells often settle relatively slowly. A higher-than-average rate could be a sign of inflammation in the body. Therefore, an ESR test can help determine if one has a condition that causes inflammation, monitor the progress of inflammatory diseases, and evaluate response to treatment.

C-reactive protein (CRP) in the blood is produced by the liver and released into the bloodstream.A high level of CRP indicates inflammation . A CRP quantitative test may detect or monitor inflammation in acute or chronic diseases such as bacterial or viral infections, Crohn's disease, ulcerative colitis, rheumatoid arthritis, and other gastrointestinal illnesses such as inflammatory bowel diseases and lung conditions like asthma.

A rheumatoid factor test is done to measure the level of rheumatoid antibodies in the body. Rheumatoid antibodies are autoantibodies (antibodies produced against substances (antigens) produced by person’s own body). The doctor may advise this test to diagnose rheumatic diseases like rheumatoid arthritis, autoimmune diseases like Sjogren’s syndrome (an immune system disorder causing dry eyes and dry mouth), or Lupus Erythematosus (an immune disorder that can affect joints, skin, kidneys, blood cells, brain, heart, and lungs), and diagnose chronic infections.

HLA B27 by PCR is a test done using polymerase chain reaction to detect the presence of HLA B27 antigen. The presence of the human leukocyte B27 (HLA B27) antigen in the body suggests a possibility of autoimmune conditions like ankylosing spondylitis. This condition is more common in males and presents symptoms like low back pain and stiffness.

The HLA B-27 by flow cytometry test is performed on a blood sample to determine the presence of the human leukocyte antigen (HLA) that may indicate a possibility of autoimmune disease. Doctors recommend this test if they observe symptoms of chronic joint pain, swelling, and inflammation of the lower back and hips and to detect inflammatory bowel disease and other chronic inflammatory conditions. A positive test means HLA-B27 is present and indicates a higher risk for several autoimmune disorders, such as ankylosing spondylitis, spondylarthritis, rheumatoid arthritis, psoriatic arthritis, and uveitis.