Organ Toxicity

Question 1

What is the role of TH-1 response in immunotoxicity?

Answer 1

• Mainly following infx w/ intracellular bacteria and some viruses
• Synthesize IL-2, INF gamma, and TNFβ
• Activates macrophages
• Responsible for cell-mediated immunity, phagocyte responses
• Proinflammatory, perpetuates AI response

Question 2

What is the role of TH-2 response in immunotoxicity?

Answer 2

• Mainly following infestations by GI nematodes
• Secrete IL-4, IL-5, IL-10, and IL-13
• Strong Ab production
• Esosinophil activation; assoc. w/ eosinophilic response in atopy
• Pregnancy is TH-2 dominant becz strong TH-2 response is necessary to modify TH-1 response (to not reject the baby)
• Inhibition of several macrophage functions (i.e. phagocyte independent responses)

Question 3

How do toxins cause immune deficits?

Answer 3

• Hypersensitivity rxns, including allergy

- Autoimmunity

Question 4

What toxic substances can cause atrophy and/or death of cells in the thymus gland?

Answer 4

DES, Dioxin, and DDT

Question 5

What effect can PCB have allergic responses?

Answer 5

Exposure may make people prone to allergic response: more allergic responses

Question 6

What effect can PAH exposure have on humans?

Answer 6

• Effects anyone living or working in an urban environment)

- Decreased splenic and thymic activity

Question 7

What substances decrease the body’s ability to kill candida?

Answer 7

Lead and Mercury

Question 8

Supplementation of what mineral may be protective of immune function with cadmium exposure?

Answer 8

Selenium

Question 9

Define endocrine disruptor? Give some examples.

Answer 9

Def: a chemical that interferes w/ body’s endocrine system + can produce adverse responses
Ex: DES (diethylstilbestrol) – main problem was reproductive problems in offspring

Question 10

What is a xenoestrogen? Give an example.

Answer 10

It is a type of endocrine disruptor that imitates estrogen, can be of natural or synthetic origin
Ex: Phytoestrogen, from plants

Question 11

Which endocrine disrupters effect female fertility?

Answer 11

Decr. w/ PAHs, chemotherapeutic agents, solvents, BPA, particulate

Question 12

Which endocrine disrupters effect male fertility?

Answer 12

organophosphates and heavy metals affect sperm

Question 13

Which endocrine disrupter looks like thyroid hormone?

Answer 13

PCBs

Question 14

What should be done before doing specialty heavy metal testing?

Answer 14

• Blood work: CBC, CMP, Lipid Panel (consider VAP w/ CVD patients)
• Complete UA; For women: urine HCG
• G6PD (if at any point you plan to administer high dose vit. C)
• TB test (if no recent one on record)

Question 15

Is there a good test to determine accurate body burden of heavy metals?

Answer 15

No

Question 16

What are the pros to hair testing for heavy metals?

Answer 16

• When performed properly, can provide a qualitative screening test for exposure to heavy metals, but cannot dx metal toxicity
• Good for evaluating methylmercury
• CDC, EPA, and ATSDR all recognize the validity of hair mercury levels as indicator of maternal + fetal exposure to methylmercury
• Detects recent exposure (~last 3 months)
• Cheap and easy to perform

Question 17

What are the cons to hair testing for heavy metals?

Answer 17

• Once bound in hair, metals will not be reexchanged back w/ the body, therefore hair levels of metals can be a lot higher (200-300x) than blood or urine
• Only a screen: positive tests need confirmation w/ urine or blood test
• Not an indication of body burden
• Hair is highly vulnerable to external contamination (dyes, shampoos, bleaching, air pollution, contaminants in water).
• No standard procedure for washing, cutting + analyzing hair
• Not reliable for testing elemental Hg, Cd, or Pb

Question 18

Who would be a good candidate for stool testing?

Answer 18

Pediatric patients