Small dense LDL cholesterol (sdLDL-c) has been established to be highly associated with metabolic disorder.

Small dense LDL cholesterol (sdLDL-c), is a distinct LDL cholesterol subclass, which is associated with raised TG and decreased HDL-c levels in adiposity and diabetes, playing a distinct metabolic role in atherosclerosis.

The results of recent studies demonstrate that LDL fractions have different atherogenicity, with sdLDL being more atherogenic than larger LDL subfractions. sdLDL is characterized by the enhanced ability to penetrate the arterial wall that makes it a potent source of cholesterol for the development of atherosclerotic plaque. Importantly, longer circulation times of sdLDL result in multiple atherogenic modifications of sdLDL particles in plasma, further increasing its atherogenicity. Study of the sdLDL role in the development of atherosclerosis and CVD is hindered by significant variations in LDL fractionation results obtained by different methods.

These particles are associated with an increased risk of heart disease; more of these small particles lead to greater risk. Your Small LDL particle score can vary widely, with a lower score being much better. 

Smith antigens, along with RNP antigens, are part of small nuclear RNAs. Levels of antibodies to these two antigens are often elevated in SLE. The Smith antigen is composed of the B1, D, and E proteins.

Anti-Smith antibody has low sensitivity but high specificity for systemic lupus erythematosus (SLE). It is occasional present in mixed connective-tissue disease (MCTD).

Anti-Smith antibody levels are elevated in up to 30% of SLE cases and 8% of MCTD cases.

Smith/RNP (ENA) antibodies, predominantly of the IgG class, are a significant marker in the diagnostic landscape of autoimmune diseases, particularly systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). These antibodies target specific proteins found in the cell nucleus, making them a crucial component in the array of antinuclear antibodies (ANAs) often tested for in autoimmune diagnostics.

In the context of SLE, the presence of Smith/RNP antibodies is relatively rare but highly specific. This means that while not all SLE patients have these antibodies, those who do are very likely to have SLE. This specificity makes Smith/RNP antibodies an invaluable tool in distinguishing SLE from other autoimmune disorders, which can often present with similar symptoms.

Smooth Muscle Antibodies (SMA), identified through the Immunofluorescence Assay (IFA), are pivotal in diagnosing autoimmune liver diseases, particularly Autoimmune Hepatitis (AIH). SMA-IFA testing detects antibodies targeting actin, a protein in smooth muscle cells, often found in patients with AIH.

Sodium (Na+) and potassium (K+) are electrolytes that affect most metabolic functions. They serve to maintain osmotic pressure and hydration of various body fluid compartments, body pH and regulation of heart and muscle functions. Electrolytes are also involved in oxidation-reduction reactions and participate in essential enzymatic reactions. Electrolytes can be affected by state of hydration. Hemolysis can result in falsely elevated K+.

Sodium is an essential mineral for maintaining water balance and blood pressure in the body and is a primary extra-cellular element

What is a Sodium test?

This test measures the levels of sodium in your blood and is usually done as part of an electrolyte or basic metabolic panel blood test.

The sodium test may also be ordered separately if you have:

• eaten large amounts of salt
• not eaten enough or had enough water
• a serious illness, or gone through surgery
• received intravenous fluids

You may also receive this test to monitor medications that affect your sodium levels. These include diuretics and certain hormones.

Elevated or decreased amounts of sodium in your body can have many adverse health effects ranging from as minor as thirst to as serious as a coma in incredibly severe cases. Monitoring the healthy level of this essential mineral is incredibly important to your overall health.

A sodium blood test is used to detect an abnormal sodium level, including low sodium (hyponatremia) and high sodium (hypernatremia). It is often used as part of an electrolyte panel or basic metabolic panel for a routine health exam.

Sodium is an important electrolyte (a mineral in your blood and other bodily fluids) that helps your body and cells function. It helps your body regulate how much fluid it retains.