Lupus lab tests

In addition to the presence of clinical symptoms, a diagnosis of lupus is usually confirmed by laboratory tests. These same tests are used for monitoring lupus.

Tests to help in diagnosis of lupus

ANA (Antinuclear antibody)

An ANA is a test for the presence of abnormal antibodies. It is very sensitive, not well standardised and while positive in most lupus patients, it will also be positive in many a person that does not have lupus (including healthy persons). The test is used in reaching a lupus diagnosis, but has little value as a repeat test.

ENA (Extractable nuclear antigen antibodies)

A test for multiple antibodies against extractable nuclear antigens (proteins). Antibodies against Sm protein are quite specific for lupus, while antibodies against other nuclear proteins (eg SSA or RNP protein) can help define subsets of lupus. The test is helpful in reaching an lupus diagnosis, but has little value as a repeat test.

Antiphospholipid antibody

This antibody is involved in blood clotting. More blood clots form when this measure is high. The test is helpful in reaching an lupus diagnosis, but has little value as a repeat test.

Anti-dsDNA antibody

These antibodies are generally more specific for lupus than the ANA test, but are detected in only 60-70 % of lupus patients (depending on the method of detection).

Tests to help monitor disease activity in lupus over time

Note - The frequency of testing depends on the severity of lupus.

Complement Proteins

Complement Proteins are proteins in the blood that fight infections. This test measures levels of these proteins in the blood. In lupus, levels can be low as antibodies use these proteins to intensify inflammation and the test is used to see how severe the disease is or to see if a treatment is working.

ESR

Erythrocyte (ir-RITH-ro-cite) Sedimentation Rate (ESR) is a blood test that reflects a number of proteins in the blood that increase with inflammation.

CRP (C reactive protein)

CRP is also protein that is produced to fight off infections and also rises with sterile inflammation as occurs in lupus

Creatinine

Creatinine is a breakdown product of muscle tissue that is excreted by the kidneys into the urine. If the kidneys do not work well enough, creatinine levels in the blood will therefore rise.

Proteinuria

Proteinuria is the amount of protein in the urine and is normally minimal. Abnormal proteinuria is often the first signal that lupus is affecting the kidneys as they start to leak more protein in the urine.

LFT’s (Liver function tests)

LFT’s or Liver function tests is the general term for a group of tests that check how your liver is working. As the liver gets rid of many lupus drugs, it is important to check these liver enzymes regularly.

Hematocrit

This is the percent of blood that is made up of red blood cells. Low levels can be due to active lupus where red blood cells get destroyed or due to side effects of drugs for lupus.

WBC (White blood cell count)

The number and subtypes of white blood cells present in the blood. Very important in fighting off infections. Tests can give an indication how your lupus is faring and if drugs for lupus are affecting the blood production too much.

Anti-dsDNA antibody

This is one of the few autoantibodies that fluctuate over time in lupus and increasing anti-dsDNA levels can indicate an impending flare in subgroups of patients , however the association between anti-dsDNA levels and disease activity is not absolute.

Platelet count

Small blood cells that start the process of blood clotting. Low levels can be due to active lupus where platelets get destroyed or due to side effects of drugs for lupus

Other test to monitor health in SLE

Bone Density Test

Bone density is a test of how solid and how strong your bones are.

EKG

Electrocardiogram. An EKG is a recording of the electric activity of the heart.

Echocardiogram

An echocardiogram is a test that provides imaging of the heart using ultrasound technique. This allows visualisation of the heart structure and assesses pump function.

X-Ray

A picture of the bones and other parts inside of the body.