- Common in soil, plants, bathrooms, and in beverages like milk, juice, and water. 
- May be a commensal (=living in a relationship in which one organism derives food or other benefits from another organism without hurting or helping it). 
- Can cause disease in immunosuppressed patients.

Ri Antibody Screen with Reflex to Titer and Western Blot - Anti-Ri can be detected in patients with the paraneoplastic opsoclonus/myoclonus syndrome. Neoplasms most often associated with Anti-Ri include breast cancer, gynecological cancers, and small cell lung cancer.

Riboflavin, also known as Vitamin B2, is a water-soluble vitamin that plays a crucial role in energy production, cellular function, and metabolism. It is a component of two major coenzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are key players in the metabolism of carbohydrates, fats, and proteins, facilitating the production of energy (ATP) in the body. Riboflavin is also essential for the regeneration of glutathione, one of the body's main antioxidants, thus playing a significant role in protecting cells from oxidative stress and damage. Additionally, Vitamin B2 is involved in the conversion of other B vitamins, including niacin (B3) and pyridoxine (B6), into their active forms, making it essential for maintaining overall B vitamin metabolism. Its role extends to the development and function of the skin, lining of the digestive tract, blood cells, and many other parts of the body.

Anti-ribosomal P proteins antibody (anti-rib P) is a highly specific marker for systemic lupus erythematosus (SLE) and it is associated with liver involvement in this disease.

The presence of antibodies to Rice is an indication of food immune reactivity. The offending food and its known cross-reactive foods should be eliminated from the diet. Adverse reactions to Rice have been reported.

Despite its cross-reactivity to wheat, Rice is often over-consumed in a gluten-free diet, which can result in the patient developing an immune reactivity to Rice.

Elevated antibody levels can be clinically significant — while the antibodies themselves don’t destroy anything, they do trigger an inflammatory response that can cause significant destruction of tissue and resulting symptoms. This response is not necessarily dependent on antibody levels. However, an equivocal result may mean you are just beginning to exhibit an immune reaction, so this is an important time to take measures to support the body in damping immune reactivity.

Rickettsia typhi is the etiological agent of murine typhus. R. typhi is transmitted primarily by the rat flea, Xenopsylla cheopis. Lice and mites can be potential vectors and rodents, shrews, opossums, cats can be reservoir. The clinical manifestations of murine typhus are usually less severe than those of epidemic typhus and includes persistent headache, a high-grade fever, and a cutaneous rash predominating on the trunk. Murine typhus usually takes a prolonged incubation period and the characteristic rash is occasionally absent. An antibody response is usually detected only after 10 days from the onset of systemic symptoms, and antibody titers reach a peak after 3 to 4 weeks or later if an antibiotic therapy has been administered.

What is Rickettsia typhi Surface Antigen – IgM?

Rickettsia typhi is the bacterium that causes murine typhus, a flea-borne illness most commonly found in warm, coastal regions of the world, including parts of the southern United States (e.g., Texas and California). It is primarily transmitted to humans by the bite of fleas infected from rodents or, occasionally, opossums or other small mammals.

The Surface Antigen – IgM test detects IgM antibodies produced by your immune system in response to proteins on the surface of Rickettsia typhi. IgM antibodies are typically the first to appear during an infection, usually within the first 1 to 2 weeks of exposure. A positive result generally suggests a recent or active infection.

The Right Coronary Artery (RCA) is a pivotal vessel in the cardiovascular system, playing a central role in the assessment of heart health during a Coronary Calcium Scan. This scan, utilizing computed tomography (CT) technology, is designed to detect the presence of calcium deposits within the coronary arteries, indicative of atherosclerotic plaque. The RCA originates from the right aortic sinus and courses along the right atrioventricular groove, supplying blood to the right atrium, right ventricle, part of the left ventricle, the sinoatrial (SA) node in most individuals, and the atrioventricular (AV) node. The presence of calcification in the RCA, as revealed in the scan, signifies the extent of coronary artery disease (CAD) in this vessel.

The Ristocetin Cofactor (RCoF) test is a critical diagnostic assay used to measure the functional activity of von Willebrand factor (vWF), a protein essential for blood clotting. This test plays a key role in diagnosing and managing von Willebrand disease (VWD), the most common inherited bleeding disorder. By assessing how well vWF promotes platelet aggregation in the presence of ristocetin, the RCoF test provides a quantitative measure of vWF function. It is highly specific for detecting dysfunctional vWF (e.g., in type 2 VWD) and is often paired with vWF antigen testing to differentiate between quantitative and qualitative defects. The test is also used to monitor treatment efficacy, assess surgical bleeding risks, and detect acquired von Willebrand syndrome. While factors like blood type, stress, or pregnancy can influence results, advances such as automated assays and recombinant ristocetin analogs have improved accuracy and efficiency, solidifying the RCoF test as an indispensable tool in hematology.

Rocky Mountain spotted fever (RMSF) can be difficult to diagnose due to the non-specific signs and symptoms in early stages of illness. Signs and symptoms can vary from patient to patient and can resemble other, more common diseases. Nonetheless, early consideration of rickettsial disease in the differential diagnosis and empiric treatment is crucial to prevent severe illness and death.

Rocky Mountain spotted fever (RMSF) is a bacterial disease spread through the bite of an infected tick.

The RMSF (Rocky Mountain Spotted Fever) IgG by IFA (Indirect Fluorescent Antibody) marker is a vital component of the serological testing for the diagnosis of Rocky Mountain Spotted Fever, a serious tick-borne illness caused by the bacterium Rickettsia rickettsii. This test is designed to detect Immunoglobulin G (IgG) antibodies that the immune system produces in response to an infection with R. rickettsii. IgG antibodies are a crucial part of the adaptive immune response, generally developing within a few weeks following the initial exposure to the pathogen and persisting in the bloodstream for a prolonged period, thereby indicating either past exposure or a chronic infection.

This test measures IgM antibodies to Rocky Mountain Spotted Fever.

IgM antibodies to RMSF are typically detectable within 1-2 weeks of infection.  They will typically no longer be detectable after a few months. 

Testing for RMSF is recommended for anyone who develops symptoms after being bitten by a tick or spending time outdoors in areas where ticks are prevalent. RMSF Antibody testing can sometimes show false positives due to cross-reactivity with other illnesses including Lyme Disease.

RNA Polymerase III antibodies are a specific type of autoantibody that can play a significant role in helping doctors understand certain health conditions. Imagine your body's immune system as a well-trained security system. Sometimes, this system mistakenly identifies parts of your own body as threats, producing antibodies against them - this is where RNA Polymerase III antibodies come into play. These antibodies target an enzyme called RNA Polymerase III, which is crucial for generating certain types of RNA molecules inside your cells.