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Quinolinic Acid (OA)

Urine

NutriStat Basic Profile, US BioTek

Optimal range:   0 - 9.74 ug/mgCR

Kynurenic acid and Quinolinic acid are tryptophan metabolites formed through the kynurenine pathway. Tryptophan is the amino acid precursor to serotonin; its major route for catabolism is the kynurenine pathway. Important products of the kynurenine pathway include xanthurenic acid and kynurenic acid, which can further metabolize into quinolinic acid. The historical importance of this pathway has mainly been as a source of the coenzyme NAD+, which is important for all redox reactions in the mitochondria.

However, it is now understood that kynurenic and quinolinic acid have physiologic implications. This alternate pathway is upregulated in response to inflammation and stress, which can lead to deficient serotonin production. Kynurenic acid has shown some neuroprotective properties in the brain, since it can stimulate NMDA receptors. However, its importance on the periphery is still not fully elucidated. Some studies outline antiinflammatory, analgesic, antiatherogenic, antioxidative, and hepatoprotective properties to peripheral kynurenic acid.

The correlation to levels of urinary excretion needs further study. Quinolinic acid, in and of itself, can be inflammatory and neurotoxic.

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Quinolinic acid (Quinolinate) (Genova)

Organix Comprehensive Profile - Urine, Genova Diagnostics

Optimal range:   0 - 5.8 mcg/mg creatinine

Quinolinic acid is a neurotoxic substance produced by our own bodies and a metabolite of tryptophan.

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Quinolinic acid/5-HIAA

Organic Acids, Vibrant Wellness

Optimal range:   0.32 - 1.1 Ratio

A high ratio of quinolinic acid to the tryptophan metabolite, 5-hydroxyindoleacetic acid, indicates excessive inflammation due to recurrent infections, excessive tryptophan intake, immune overstimulation, excessive adrenal production of cortisol, or excessive exposure to phthalates.

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Quinolinic acid/5-HIAA Ratio

Neurotransmitters (VibrantWellness), Vibrant Wellness

Optimal range:   0.32 - 1.1 Ratio

A high ratio of quinolinic acid to the tryptophan metabolite, 5-hydroxyindoleacetic acid, indicates excessive inflammation due to recurrent infections, excessive tryptophan intake, immune overstimulation, excessive adrenal production of cortisol, or excessive exposure to phthalates.

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R. rickettsii IFA - IgG

Rickettsiosis

Optimal range:   0 - 40 titer

The R. rickettsii IFA - IgG marker on a Rickettsiosis panel is a crucial diagnostic tool for identifying infection with Rickettsia rickettsii, the bacterium responsible for Rocky Mountain spotted fever (RMSF), a potentially severe tick-borne illness. This serological test detects Immunoglobulin G (IgG) antibodies that the immune system produces specifically in response to an R. rickettsii infection. IgG antibodies are part of the body's later immune response, typically developing a few weeks after initial exposure to the pathogen and potentially persisting for years, thus indicating either past exposure or chronic infection.

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An "Indeterminate" result (if result falls in orange reference range) in the R. rickettsii IFA - IgG test indicates that the detected levels of IgG antibodies against Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever (RMSF), are unclear and do not conclusively fall within the defined positive or negative ranges. This ambiguous result can be due to several reasons. It might suggest that the antibody levels are at a borderline range, possibly indicating an early immune response where the antibodies are just starting to develop and have not reached a level high enough to be considered positive. Alternatively, it could be a sign of declining antibody levels from a past infection that is resolving or has already resolved, where the antibodies are present but at diminishing levels. An indeterminate result can also arise from technical issues in the test procedure or cross-reactivity with antibodies from other similar infections. In such cases, further evaluation is necessary, often including a clinical assessment of symptoms, patient history, and possibly additional diagnostic tests, such as a repeat IgG test after some time or other serological tests like IgM testing. This indeterminate outcome highlights the complexity of diagnosing RMSF based solely on serological testing and underscores the importance of a comprehensive clinical assessment to accurately determine the infection status.

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R. typhi IFA - IgG

Rickettsiosis

Optimal range:   0 - 40 titer

The R. typhi IFA - IgG marker on a Rickettsiosis panel is a specialized diagnostic tool used for the detection of IgG antibodies against Rickettsia typhi, the causative agent of murine typhus. This serological assay plays a critical role in the diagnosis of the disease, particularly in epidemiological settings where murine typhus is prevalent. IgG antibodies are a key component of the adaptive immune response, typically developing within a few weeks following exposure to a pathogen and persisting for an extended period, thereby indicating past exposure or a possible chronic infection.

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An "Indeterminate" result (a result that falls within the orange reference range) in the R. typhi IFA - IgG test signifies that the levels of IgG antibodies against Rickettsia typhi, the bacterium responsible for murine typhus, are ambiguous and do not clearly fall into the positive or negative categories. This uncertain result can occur for several reasons. It may indicate that the antibody levels are at a borderline, possibly suggesting an early stage of the immune response where antibodies are just starting to develop but haven't reached a definitive positive level. Alternatively, it could be a sign of declining antibody levels from a past infection that is resolving or has already resolved, where the antibodies are present but at diminishing levels. Technical factors within the test itself or cross-reactivity with antibodies from other similar pathogens can also contribute to an indeterminate result. In such cases, further evaluation is often necessary, including a clinical assessment of symptoms, patient history, and possibly additional diagnostic tests, such as a repeat IgG test after some time or IgM testing. This indeterminate outcome emphasizes the need for a comprehensive approach in diagnosing murine typhus, considering serological results alongside the broader clinical picture to accurately determine the infection status.

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RA Latex Turbid

Immune System

Optimal range:   0 - 13.9 IU/ml

The rheumatoid arthritis (RA) latex turbid test is a laboratory test that’s used to help your doctor diagnose rheumatoid arthritis and other autoimmune diseases.

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Radish

Array 10 - Multiple Food Immune Reactivity Screen, Cyrex Laboratories

Optimal range:   0.1 - 1.7 ELISA Index

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Radish

LRA (Lymphocyte Response Assay), ELISA/ACT Biotechnologies

Reference range:   Strong reaction, Moderate reaction, No reaction

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Radish / Daikon, IgG

240 Food Panel: IgA, IgG, IgG4 (US BioTek), US BioTek

Reference range:   Very Low, Low, Moderate, High, Very High

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RANTES

Cytokine Response Profile (CytoDx), Diagnostic Solutions, Diagnostic Solutions Laboratory | GI-MAP & Food Sensitivity Tests

Optimal range:   26460.9 - 96117.3 Units

T-Cell-Specific Protein RANTES is chemotactic for T-cells, human eosinophils and basophils and plays an active role in recruiting leukocytes into inflammatory sites. It also activates the release of proteins from eosinophils such as eosinophilic cationic protein. It changes the density of eosinophils and makes them hypodense, which is thought to represent a state of generalized cell activation and is associated most often with diseases such as asthma and allergic rhinitis.

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Rapid plasma reagin (RPR)

Infectious Disease Profile

Optimal range:   0 - 0 Units

The rapid plasma reagin (RPR) is a test used to screen for syphilis. The RPR test measures IgM and IgG antibodies to lipoidal material released from damaged host cells as well as to lipoprotein-like material, and possibly cardiolipin released from the treponemes. 

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RATIO (APO B / APO A-1)

NutriStat, NutriPATH

Optimal range:   0.45 - 1.25 Ratio

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RATIO (CBA/VW AG)

Immune System

Optimal range:   0.5 - 1 Ratio

The von Willebrand Factor Collagen Binding Activity to von Willebrand Factor Antigen ratio (vWF:CB/vWF:Ag) is a critical diagnostic parameter in the evaluation of von Willebrand Disease (VWD). This ratio provides essential information about the functional quality of von Willebrand Factor molecules relative to their quantity in circulation.

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Ratio: DHEA/7keto DHEA

ZRT Laboratory (Salivary Steroids), ZRT Laboratory

Optimal range:   0.5 - 2 Ratio

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Ratio: Norepi/Epi

ZRT Laboratory (Urinary Neurotransmitters), ZRT Laboratory

Optimal range:   5.2 - 13.7 µg/g creatinine

Norepinephrine and epinephrine are catecholamine messengers that play important roles in the regulation of diverse physiological systems by acting through adrenergic receptors. 

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Ratio: Pg/E2

ZRT Laboratory (Salivary Steroids), ZRT Laboratory

Optimal range:   100 - 500 Ratio

Optimal: 100-500 when E2 1.3-3.3 pg/mL

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Ratio: Pg/E2 (Saliva LCMS)

ZRT Laboratory (Salivary Steroids), ZRT Laboratory

Optimal range:   23 - 196 Ratio

This ratio is helpful when both E2 and Pg are within range, yet the patient continues to have symptoms. It is not expected to be normal or used clinically when either E2 and/or Pg are outside of their expected ranges or if the patient does not have clinical symptoms.

Is the ratio relevant in women using hormone therapy?

With some types of hormone therapy such as topical progesterone, Pg levels in saliva are much higher than endogenous luteal phase levels, ranging from 200-3000 pg/mL at 12-24 hours after dosing, and so the ratio can appear high. However, because symptoms of both estrogen dominance and progesterone dominance can look the same, testing and assessing the ratio along with clinical symptoms can help determine the next step for treatment.    

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Ratio: Zn/Cu

Blood

Blood Spot Toxic & Essential Elements, ZRT Laboratory

Optimal range:   6.16 - 10.3 Ratio

The zinc-to-copper ratio (Zn/Cu ratio) is a key indicator of trace mineral balance in the body. Both zinc and copper are essential nutrients that support numerous physiological functions, but they also act in opposition in several biological processes. Maintaining the right ratio between them is more important than the absolute level of either mineral alone.

Why the Zn/Cu Ratio Matters

  • Zinc supports immune function, wound healing, DNA synthesis, antioxidant activity, and enzyme function.

  • Copper plays a role in energy production, nervous system health, iron metabolism, and connective tissue formation.

When the Zn/Cu ratio is balanced, these minerals complement each other. However, an imbalance—whether due to excess copper, low zinc, or both—can disrupt enzyme activity and contribute to oxidative stress, inflammation, and immune dysfunction.

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RBC

GI360 stool profile, Doctor's Data

Reference range:   Not Detected, Few, Moderate

Red Blood Cells (RBC) in the stool may be associated with a parasitic or bacterial infection, or an inflammatory bowel condition such as ulcerative colitis. Colorectal cancer, anal fistulas, and hemorrhoids should also be ruled out.

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