Synonym/Acronym
delta-ALA, delta-aminolevulinic acid.
Rationale
To assist in diagnosing inherited conditions that disrupt heme synthesis, such as acute hepatic porphyria and tyrosinemia that primarily affect the liver. This study also assists in diagnosing acquired causes that disrupt porphyrin synthesis, such as acute heavy metal poisoning.
Patient Preparation
There are no food, activity, or medication restrictions unless by medical direction. Instruct the patient to avoid alcohol consumption for 24 hr prior to specimen collection; increased ALA excretion is associated with alcohol consumption. Usually, a 24-hr urine collection is ordered, but random specimens are accepted. As appropriate, provide the required urine collection container and specimen collection instructions.
Normal Findings
Method: Ion exchange chromatography/Spectrophotometry.
| Conventional and SI Units (Conventional units × 7.626) |
|---|
| Amino levulinic acid/random (minimum 2 mL urine) | 0–35 µmol/L |
| Amino levulinic acid/24-hr collection | 0–61 µmol/24 hr |
Signs and symptoms of an acute porphyria attack include pain (commonly in the abdomen, arms, and legs), nausea, vomiting, muscle weakness, rapid pulse, and high blood pressure. Possible interventions include medication for pain, nausea, and vomiting, and, if indicated, respiratory support. Initial treatment following a moderate to severe attack may include identification and cessation of harmful drugs the patient may be taking, IV infusion of glucose, and IV heme therapy (hematin, heme arginate) if indicated by markedly elevated urine delta-ALA and porphyrins.
(Study type: Urine from a timed specimen collected in a dark plastic container with glacial acetic acid as a preservative; related body system: Circulatory/hematopoietic system.)
Delta-ALA is involved in the formation of porphyrins, which ultimately leads to hemoglobin synthesis. Toxins including alcohol, lead, and other heavy metals can inhibit porphyrin synthesis. Accumulated delta-ALA is excreted in urine. Symptoms of the acute phase of intermittent porphyrias include abdominal pain, nausea, vomiting, neuromuscular signs and symptoms, constipation, and occasionally psychotic behavior. Hemolytic anemia may also exhibit during the acute phase. For additional information regarding evaluation of the porphyrias and heavy metal intoxication, refer to the studies titled “Lead” and “Porphyrins, Blood and Urine.”
Delta-ALA is a test of choice in the diagnosis of acute intermittent porphyria, ALA dehydratase deficiency porphyria, and delta-ALA dehydratase deficiency. Analysis of porphobilinogen and porphyrins may also be requested to assist in differential diagnosis of the porphyrias. Although lead poisoning can cause increased urinary excretion, the measurement of delta-ALA is not useful to indicate lead toxicity because it is not detectable in the urine until the blood lead level approaches and exceeds 45 mcg/dL (SI = 2.17 micromol/L), the level at which children should be evaluated to determine the need for chelation therapy.
Increased In
Related to inhibition of the enzymes involved in porphyrin synthesis; results in accumulation of delta-ALA and is evidenced by exposure to medications, toxins, diet, or infection that can precipitate an attack.
- Acute porphyrias
- Aminolevulinic acid dehydrase deficiency (related to the inability to convert delta-ALA to porphobilinogen, leading to accumulation of delta-ALA)
- Heavy metal poisoning
- Hereditary tyrosinemia
Decreased In
N/A
Before the Study: Planning and Implementation
Teaching the Patient What to Expect
- Discuss how this test can assist with identification of a disease that interrupts the normal formation of hemoglobin.
- Explain that a urine sample is needed for the test. Unless contraindicated, encourage oral fluid intake during the collection period. Information regarding urine specimen collection is presented with other general guidelines in Appendix A: Patient Preparation Specimen Collection.
Potential Nursing Actions
- Include on the collection container’s label urine total volume, test start and stop times/dates, and any medications that may interfere with test results.
- Discuss the symptoms of heavy metal poisoning by age group.
- Adult symptoms include hypertension, memory lapses, difficulty in concentrating, reported pain (headache, muscles, joints, abdomen), fertility (low or abnormal sperm, miscarriage, stillborn, prematurity), dehydration, tingling, ascites (fluid on the lungs), constipation, weakness, fatigue, mood disturbances, organ damage (liver, kidney, lung).
- Child symptoms include developmental delays with difficulty learning, nutrition issues (pica, vomiting, appetite and weight loss), neurological issues (irritability, hearing loss, seizures), gastrointestinal issues (constipation and abdominal pain), organ damage (liver, kidney, lung).
- Newborn symptoms include premature birth, lower birth weight with slower growth pattern.
After the Study: Implementation & Evaluation Potential Nursing Actions
Avoiding Complications
- Compare the quantity of urine with the urinary output record for the collection at the conclusion of the test. If the specimen contains less than what was recorded as output, some urine may have been discarded, invalidating the test.
Treatment Considerations
Inherited Porphyria
- Laboratory tests are available for identifying and classifying porphyrias. Genetic testing is available for identifying specific gene sequence variations that result in inherited porphyrias. The Genetic Testing Registry lists laboratories that offer genetic testing for some types of porphyria, https://www.ncbi.nlm.nih .gov/gtr/all/?term=porphyria.
Acquired Porphyria
- Discuss common situations that can result in exposure to toxic heavy metals (e.g., aluminum, arsenic, cadmium, lead, mercury).
- Items in the home such as ceramic glazed tableware, scratched aluminum pots/pans, aluminum foil (used in cooking), interior paint, carpeting, furniture, mattresses, household dust, pottery, cosmetics (e.g., antiperspirant deodorant), or toys.
- Household water sources contaminated by lead pipes.
- Items imported from other countries such as holistic medicinals or cultural food additives (e.g., tamarind on candy).
- Environmental and workplace risks (e.g., soil from yards or playgrounds that has absorbed heavy metals over time).
- Intervention/actions include the following: Discuss precautions that can be taken to prevent heavy metal exposure: frequent handwashing, keeping the home dust free, avoiding the use of tap water from lead pipes for cooking or making baby formula. Modify diet and food purchasing habits to ensure absence of heavy metal–contaminated kitchen cookware (ceramics), utensils, and foods while maintaining a healthy diet.
- Explain how to assess the environment for heavy metal exposure sourced from old leaded paint, contaminated soil, contaminated ceramics or pottery used for food preparation and dining, and old toys. Decrease environmental exposure by removing all decorative ceramics, toys, loose paint that contain heavy metals.
- Discuss the potential for exposure related to adult hobbies, which may disrupt mental acuity; the use of products containing heavy metals; restoration that includes sanding or removal of old leaded paint; work-related heavy metal exposure (mining, battery manufacturing, construction).
Safety Considerations
- Slow exposure to heavy metals in the environment or products in the home can cause irreversible damage over time to brain, kidneys, and nervous system and can lead to death.
Nutritional Considerations
- Increased delta-ALA levels may be associated with an acute porphyria attack.
- Patients prone to porphyria attacks should eat a normal or high-carbohydrate diet. Dietary recommendations for those with porphyria will vary depending on the condition and its severity. Wide variations or restrictions in dietary carbohydrate content should be avoided, even for short periods of time.
- Treatment of an acute attack may include IV administration of dextrose (glucose) and heme. Less severe attacks may be treated with oral sources of dextrose (e.g., sugar added to orange juice). Glucose suppresses an enzyme involved in heme production, and the infusion of available heme also decreases the level of heme synthesis/heme precursors in the blood. After recovering from a porphyria attack, the patient’s daily intake of carbohydrates should be 300 g or more per day.
- Some canned goods and candies imported from other countries may have been produced using heavy metal–contaminated ingredients (e.g., tamarind products packed in heavy metal-glazed pots, minimally refined chili powder), heavy metal–contaminated ink used to label candy packaging, or by poor manufacturing and storage processes. As appropriate, health-care providers should provide culturally sensitive education and discuss the safety issues related to consuming imported canned foods and candies.
Clinical Judgement
- Consider how to address the cultural and socioeconomic barriers to the prevention of heavy metal poisoning.
Follow-Up Evaluation and Desired Outcomes