BLOOD SUGAR LEVEL – Fasting (BSL-F)

A 10-12 hour fasting sample is advisable.

Diagnostic for diabetes. Certain drugs like steroids can raise blood sugar level. Often a oral glucose tolerance test is required to confirm diabetes in asymptomatic patient with raised BSL

BLOOD SUGAR LEVEL – Random (BSL-R)

Used to screen BSL in a non fasting state or any time not necessarily 2 hours post prandial

Abnormal values need to be checked with fasting and post prandial testing

BLOOD SUGAR LEVEL – Post prandial (BSL-PP)

A post-prandial sample 2 hours after lunch is best preferred.

Both BSL (F) and BSL (PP) are commonly done for diagnosis and monitoring of diabetics.

KIDNEY FUNCTION TESTS (KFT)

Blood urea nitrogen and serum creatinine level; fasting state not required.

To assess kidney function; should be done for evaluation of systemic rheumatic diseases and prior to beginning long term drugs; must be done to monitor drugs with potential kidney side effects. Kidneys may be affected in certain rheumatic diseases (SLE, Gout) and by long term use of pain killers and other drugs.

SERUM URIC ACID

Fasting state not required; normal range varies form lab to lab; different normal values for men and pre-menopausal women.

For diagnosis of gout but asymptomatic raised values need clinical correlation. The diagnosis of gout is essentially clinical and should be based on a classical clinical profile. Kidney functions must be also checked as uric acid is excreted by the kidneys. Patients with prolonged raised levels of serum uric acid or gout must also be screened for elevated lipids and cardiovascular diseases. Pre-menopausal women rarely if ever suffer from gout.. Certain drugs e.g. Diuretics, beta-blockers, can also cause elevated serum uric acid levels.

SERUM CALCIUM

Fasting state not required; total calcium is usually measured though it is the free fraction which is more important. Several factors influence blood levels.

Blood levels do not per se indicate calcium deficiency. Other test (e.g. XRays, fraction measures, etc) are more important. Calcium levels are of importance in parathyroid disorders, multiple myeloma, metabolic bone disorder.

SERUM PHOSPHOROUS

Fasting state not required; Routinely interpreted with calcium levels.

Important in metabolic bone disorders, renal disease.

LIVER FUNCTION TESTS (LFT)

Fasting state not required. includes serum proteins (albumen & globulin), serum bilirubin, and serum enzymes- gamma GT, SGPT, SGOT and Alkaline phosphatase.

The need to do for entire LFT or one of its components may depend upon the indication in any particular patient. Usually, full LFT is done as part of a health check up or before beginning long term therapy. Later, serum enzymes esp gamma GT or SGPT is used to monitor drug effects in long term therapy (e.g. methotrexate, Leflunomide, etc). Certain rheumatic diseases e.g. SLE may affect liver. But LFT is more important to monitor drug effects. Low serum albumin may indicate poor nutrition. Altered liver enzymes and, increased bilirubin is seen in various viral hepatitis, alcoholic hepatitis etc. Serum bilirubin is a marker for jaundice.

LIPID PROFILE

At least 14 hours fasting is desirable. Includes serum cholesterol, triglycerides, High Density cholesterol (HDL), Low Density cholesterol (LDL) and Very Low Density Level Cholesterol (VLDL).

Hyperlipidemia is a common co-existing condition in many patients with RA, SLE, gout and being a coronary risk factor, should be identified at the earliest. Some anti-rheumatic drugs e.g. Steroids can also alter serum lipids levels.

CREATININE PHOSPHOKINASE (CPK)

Fasting state not required; It is the most sensitive enzyme for muscle diseases.

Elevated in various disorders with muscle necrosis or injury. Such conditions include polymyositis, rhabdomyolysis, trauma, and some neuromuscular dystrophies.

URINE ROUTINE ANALYSIS

Fasting state not required; need not be early morning sample; includes physical, chemical and microscopic examination.

Several kidney and systemic diseases can be suspected from an abnormal urine analysis report. Routine examinations can provide a clue for raised blood sugar level, an elevated bilirubin and urinary tract infection. Elevated proteins and/or cellular casts (red blood cells) indicate primary kidney disease like nephritis.

SYNOVIAL FLUID ANALYSIS

Fasting state not required Aspiration of synovial fluid is a bed-side procedure. Gross examination, chemical analysis and microscopy are performed. A centrifuged deposit is examined for crystals.

Synovial fluid analysis is very useful to narrow the differential diagnosis of single or few joint arthritis. Synovial fluid analysis is important to clinch the diagnosis of infections (both pyogenic and tuberculosis) and gout (demonstration of crystals).

HAEMOGLOBIN (Hb)

Fasting state not required; reflects the oxygen carrying capacity of blood. Normal range varies from lab to lab and differs between men and women.

Mild to moderate anaemia (low Hb) is frequently seen in many forms of active chronic inflammatory rheumatic diseases such as RA.

TLC & DLC (Total and differential leukocyte count)

Total white cell (leukocyte) counts are expressed as cells per unit volume of blood. DLC is to count individual type of white cells.

Increased TLC indicates infection but may also be seen in active inflammatory arthritis especially in the children. Leucopoenia, a low white cell count, is often found in Felty Syndrome and SLE. Leucopoenia, sometimes due to drugs, may also indicate bone marrow suppression.

PLATELET COUNT

It is generally a part of routine hemogram (Hb and differential cell count) .

High platelet count is often seen in many inflammatory rheumatic diseases as marker of disease activity. Platelet count must be monitored during therapy with potent anti rheumatoid drugs such as methotrexate.

ERYTHROCYTE SEDIMENTATION RATE (ESR)

The ESR is preferably done on a fasting sample. A significantly high ESR irrespective of food intake has a clinical value. Westergren method is preferred in rheumatology. Normal values differ between sexes.

The ESR is a non-specific marker of inflammatory activity. Serial measurements of ESR may indicate improvement or worsening, and are useful to monitor drug response

RHEUMATOID FACTOR (RF)

Fasting state not required. A measure of its titre (amount) is useful and should always be done. Generally, a positive value is considered to be higher than 40 IU/ml

Useful for diagnosis of Rheumatoid arthritis. RF is present in the serum of 75-80% of patients with RA at some time during the disease course. However, RF is a non-specific test and a positive RF is observed in 5-6% of healthy population at low titre. A positive test needs clinical correlation.

C-REACTIVE PROTEIN (CRP)

Fasting state not required ; the amount should always be measured as a titre

It is a non-specific marker of inflammation which can be performed any time even in a non fasting state. Just like ESR, serial measurements of the CRP are useful in following the clinical activity of RA and other inflammatory arthritis.

ANTINUCLEAR ANTIBODY (ANA)

Fasting state not required; it is an expensive test and should not be done as a routine in every patient of arthritis.

ANA occur in high frequency in systemic rheumatic diseases. Useful as a screening test for systemic connective tissue disorders / collagen vascular disease. Some drugs can cause positive ANA. A positive ANA is associated with a number of infections, neoplastic diseases and other conditions.

ANTI dsDNA ANTIBODY

Fasting state not required; an expensive test

An indicator of diagnosis, disease activity and response to treatment in cases of SLE. It is rarely positive in other diseases

ANTINUCLEAR ANTIBODY - WESTERN BLOT

Fasting state not required; A expensive test; can screen several antinuclear antibodies at one time.

The various nuclear antigens include Anti Smith antibody (Sm), Anti Ribonuclear protein(RNP), Anti SSA, Anti SSB, Anti Scl-70, Anti Jo-1, Anti PCNA, Anti Centromere antibody etc. Some of the above antibodies are diagnostic for certain connective tissue disorders e.g. Scleroderma, MCTD

ANTI – CYCLIC CITRULLINATED PEPTIDE (CCP)ANTIBODIES

Fasting state not required; an expensive test.

Newly described markers in rheumatoid arthritis. Useful in patients of rheumatoid arthritis who do not show rheumatoid factor

ANTI-STREPTOLYSIN ‘O’ TITER (ASO)

Fasting state not required

For detection of Rheumatic Fever & its complications but Clinical correlation is a must May be raised in any streptococcal infection.

VDRL

Fasting state not required

A test for syphilis. Several sexually transmitted infections can cause arthritis

HLA-B27 by Polymerase Chain Reaction (PCR)

Fasting state not required; a special immunogenetic marker; the technique requires sophisticated equipment

A genetic marker for Ankylosing Spondylitis & related Seronegative forms of arthritis. 6-8% of healthy population may also show B27