Anti-RNP antibodies are a key biomarker used in diagnosing autoimmune diseases, particularly mixed connective tissue disease (MCTD), where they are present in nearly all patients. These antibodies target the U1 small nuclear ribonucleoprotein (U1 snRNP) and are also found in other conditions such as systemic lupus erythematosus (SLE), scleroderma, and polymyositis, though in lower percentages. While high levels of anti-RNP antibodies are diagnostic of MCTD, they can also indicate milder disease manifestations in other autoimmune conditions, such as Raynaud's phenomenon and less severe renal involvement in SLE. Testing methods like ELISA and immunoblotting are commonly used to detect these antibodies, which provide valuable insights into autoimmune disease mechanisms but must be interpreted alongside clinical symptoms and other diagnostic results.

The Anti-Ro (SS-A) Antibody test is a critical diagnostic tool in the assessment of autoimmune diseases. This test detects antibodies against the Ro/SS-A antigen, a protein implicated in the development of certain autoimmune conditions. The presence of Anti-Ro (SS-A) antibodies is notably associated with Sjögren's syndrome, a disorder characterized by dry eyes and mouth, and systemic lupus erythematosus (SLE).

The S100B is a calcium-binding peptide and is used as a parameter of glial activation and/or death in many disorders of the central nervous system (CNS). It plays important roles in normal CNS development and recovery after injury.

Although S100B is mainly found in astroglial and Schwann cells, it also has extracerebral sources.

S100B is a useful neurobiochemical marker of brain damage such as in circulatory arrest, stroke and traumatic brain injury.

S100B is also associated with neurodegenerative diseases like Alzheimer's disease or other chronic neurological diseases.

The S100B is a calcium-binding peptide and is used as a parameter of glial activation and/or death in many disorders of the central nervous system (CNS). It plays important roles in normal CNS development and recovery after injury.

Although S100B is mainly found in astroglial and Schwann cells, it also has extracerebral sources.

S100B is a useful neurobiochemical marker of brain damage such as in circulatory arrest, stroke and traumatic brain injury.

S100B is also associated with neurodegenerative diseases like Alzheimer's disease or other chronic neurological diseases.

Anti-sarcolemma antibodies are a type of antibodies that can be found in certain medical conditions. They are specifically associated with cardiac muscle disorders and are often detected in patients with conditions such as Dressler's syndrome after myocardial infarction, cardiomyopathy, myocarditis, rheumatic fever, and those who have undergone cardiac surgery. These antibodies can target various antigens, including adenine nucleotide translocator protein, cardiac myosin, and tropomyosin.

Antisarcolemmal (ASAs) are a serologic hallmark of inflammatory heart muscle disease (= Myocarditis) and its sequelae (= any complication or condition that results from a pre-existing illness, injury, or medical intervention).

Myocarditis is inflammation of the heart muscle (myocardium). The inflammation can reduce the heart's ability to pump blood. Myocarditis can cause chest pain, shortness of breath, and rapid or irregular heart rhythms (arrhythmias).

Anti-Scl-70 antibodies, also known as Anti-Topoisomerase I antibodies, are a specific type of autoantibody primarily associated with systemic sclerosis (scleroderma), a chronic autoimmune disease. These antibodies target the enzyme topoisomerase I, which is involved in DNA replication and repair. The presence of Anti-Scl-70 antibodies is clinically significant as they are found in approximately 20-40% of patients with systemic sclerosis, particularly in those with the diffuse cutaneous form of the disease.

Anti-Sm antibodies (Anti-Smith antibodies) are autoantibodies that are strongly associated with systemic lupus erythematosus (SLE), a chronic autoimmune disease. The presence of Anti-Sm antibodies is considered a specific marker for SLE, as these antibodies are rarely found in individuals without the disease. It is reported that approximately 99% of individuals without SLE lack Anti-Sm antibodies, but they are present in only about 20% of people with SLE, indicating that while their presence is highly specific to SLE, they are not found in all cases of the disease.

The Anti-Smith Antibody targets your body’s own proteins and is found almost exclusively in people with lupus. Though not all people with lupus have this antibody (only around 30%), those who do usually receive a diagnosis of lupus. Anti-Smith antibody is more common in blacks and Asians with SLE (around 60%) than in whites with SLE.

Smooth muscle antibodies (SMA) are the standard diagnostic marker of autoimmune hepatitis (AH).

Anti-SRP Ab (Signal Recognition Particle Antibody), as measured by reference laboratories such as RDL (Reference Diagnostics Laboratory), is a highly specific serological marker crucial in the diagnosis and management of autoimmune myopathies, particularly Polymyositis and Dermatomyositis. The signal recognition particle (SRP) is a cytoplasmic ribonucleoprotein involved in the translocation of secretory and membrane proteins. In autoimmune contexts, the immune system aberrantly produces antibodies against SRP, leading to muscle inflammation and damage.

Anti-Ro (SS-A) is an autoantibody associated with SLE or Sjögren’s syndrome. Sjögren’s syndrome is an autoimmune disorder in which the body's immune system mistakenly reacts to the tissue in glands that produce moisture, such as tear and salivary glands.

Anti-SS-B (anti-La) is an autoantibody associated with SLE or Sjögren’s syndrome. Sjögren’s syndrome is an autoimmune disorder in which the body's immune system mistakenly reacts to the tissue in glands that produce moisture, such as tear and salivary glands.

The marker "Anti-Streptococcal A (IgG)" is a specialized test designed to detect the presence of IgG antibodies against Streptococcus A bacteria in the blood. Streptococcus A is a type of bacteria that can cause various infections, ranging from mild throat infections (like strep throat) to m

If Anti-Streptococcal A (IgG) is mildly elevated, it suggests that there may have been a recent or past streptococcal infection. Anti-Streptococcal A antibodies are typically produced in response to Group A Streptococcus (GAS) infection, such as strep throat, scarlet fever, or skin infections.

Possible Implications of Mild Elevation:

1. Recent or Past Infection:
   A mildly elevated Anti-Streptococcal A (IgG) can indicate that the body has encountered Group A Streptococcus in the past, but it might not necessarily reflect an active infection. IgG antibodies appear after the acute phase of infection and can remain elevated for weeks to months following recovery.

2. Post-Infection Immunity:
   A mild increase in Anti-Streptococcal A IgG may simply represent a normal immune response as the body has developed immunity to Group A Streptococcus after a previous infection. This suggests that your immune system has successfully responded to the bacteria, and you may have protection against future infections by the same pathogen.

3. Risk for Post-Streptococcal Sequelae:
   While IgG antibodies typically indicate past exposure, elevated levels may also be seen in cases of post-streptococcal sequelae such as rheumatic fever or post-streptococcal glomerulonephritis. These are conditions that can develop weeks after an untreated or inadequately treated streptococcal infection. In such cases, the elevation is usually accompanied by other clinical symptoms (such as joint pain, heart inflammation, or kidney issues) and may require further diagnostic investigation.

4. Chronic or Recurrent Infections:
   In rare cases, mildly elevated IgG levels can occur if there have been chronic or recurrent infections with Group A Streptococcus, possibly due to incomplete treatment or recurrent throat infections. This may necessitate additional investigation or a more thorough assessment of infection history and treatment.

Interpretation and Next Steps:

• Clinical Correlation: A mildly elevated Anti-Streptococcal A IgG should always be interpreted in the context of clinical symptoms and history. If you have recently had a strep infection or symptoms like sore throat, fever, or skin infections, it may be a sign that your immune system is responding appropriately.

• Follow-Up Tests: If there are concerns about post-streptococcal sequelae (such as rheumatic fever or glomerulonephritis), further tests may be needed, such as:

  • Anti-Streptolysin O (ASO) titers: A more direct marker of recent streptococcal infection.

  • Echocardiogram or urine tests: To rule out any complications like heart damage or kidney involvement.

• Reassessment: If no recent strep infection is evident and symptoms persist, it may be necessary to revisit the diagnosis and consider other causes for the antibody elevation.

Conclusion:

A mildly elevated Anti-Streptococcal A IgG level is often not cause for immediate concern and may reflect prior exposure or past infection with Group A Streptococcus. However, if there are concerns about recent symptoms, unresolved infections, or complications like rheumatic fever or glomerulonephritis, further clinical evaluation and testing are warranted to ensure appropriate management.

The ASO Screen measures the level of Anti-Streptolysin O (ASO) antibodies your immune system produces after a Group A Streptococcus infection. These antibodies help show whether you’ve had a recent strep throat or skin infection, even if symptoms were mild or unnoticed. This test is also used to evaluate conditions that may develop after strep infections—such as rheumatic fever or post-streptococcal glomerulonephritis—especially in children.