Urinalysis Case StudiesLab Dx Fall 2008

Case 1: A 28 year old man visits his physician complaining of an intense, sharp pain in his back and side. In a conversation with his physician, the patient confesses to eating a diet high in animal proteins such as meat, cheese, and fish. Results of a complete urinalysis are shown below.

Chemical/Physical AnalysisColor Yellow Glucose Negative Urobilinogen NormalAppearance Clear Protein Trace Blood LargeSpecific Gravity 1.025 Ketones 150mg/dL Nitrite NegativepH 5.0 Bilirubin Negative Leukocyte Negative

Microscopic Analysis>100 RBC/hpf0-3 WBC/hpf20-30 Bacteria/hpf0-5 Squamous Epithelial Cells/hpfUnidentified Crystals

Questions

1. Is the presence of WBCs with bacteria clinically significant?

2. Suggest an explanation for blood in the urine.

3. Below is a photomicrograph from the patient's urine sample:

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

**Note: Crystals were soluble in ammonia

What is the cause of the patient's condition?

a) Uric acid crystals

b) Cystine crystals

c) Triple phosphate crystals

4. What is the diagnosis and treatment for this patient?

a) Cystinuria

b) Urinary tract infection

c) Renal calculi caused by the formation of uric acid crystals

1. No. Ordinarly, bacteria in the presence of WBCs would suggest a urinary tract infection. However, the 0-3 WBC/hpf is within the reference range and therefore is of no clinical significance. The relatively low levels of bacteria are also of no clinical significance. Their presence may be due to contamination.

2. There are two possible ways that blood could get into the urine. First, if the glomerulus was in some way damaged, its efficiency as a filter may be somewhat compromised. If this was the case, RBCs, protein, and other larger particles could get into the urine. However, in this case, the high blood result with only trace amounts of protein suggests that the problem did not occur at the glomerulus. This leads to the other cause of blood in the urine: damage to the urinary tract. If any part of the urinary tract is damaged, blood could get into the urine, even if the glomerulus is working fine. Renal calculi, or kidney stones, could cause damage to the renal tubules as they flow down the urinary tract. This damage would explain the presence of blood (in the absence of large amounts of protein).

3. Uric acid crystals are not soluble in ammonia. While triple phosphate crystals may have 6 sides, they are only insoluble in basic urines. This patient's urine is acidic and also it was noted that these crystals are soluble in alkaline pH. Answer = B

4. Cystinuria is the inability to absorb the amino acid cysteine from the intestines and renal tubules. Therefore, any cystine that may be present in ones diet (foods high in animal protein) will be excreted in the urine. Cystine is insoluble in an acidic pH and thus will lead to the formation of renal calculi in the urinary tract or bladder if the pH environment is acidic. Because cysteine is not an essential amino acid and can be made from methionine, there are no physiological consequences resulting from cystinuria. However, a patient with cystinuria will be susceptible to the pain associated with renal calculi. One option for treatment may be to increase the urine volume by drinking a lot of fluids. This may prevent stone formation. Another option is to choose a diet that is free of cystine. A diet high in animal protein, similar to the one this patient was on, contains large quantities of cystine. Vegetable proteins such as nuts and beans are low in cystine and should be considered. An additional way of preventing the formation of renal calculi would be to alkalise the urine. In an alkaline urine, cystine crystals dissolve so renal calculi will not form. Medications may also be available.

Case 2: A 12 year old boy was examined in the emergency room. his mother said he was having frequent urination lasting seeral days. he was also compalining of feeling weak and tired.

Chemical/Physical Analysiscolor - pale yellowClarity - clearpH - 6.0Specific gravity - 1.025Protein - TraceGlucose - 1000mg/dlKetone - 5mg/dlNitrite - negBlood - negBilirubin - negUrobilinogen - negLeukocyte – neg

MICROSCOPICRbc - 0 to 2 per fieldWbc - 0 to 2Bacteria - fewEpithelial Cells - few

OTHER TESTSSSA( sulfosalicylic acid test) - trace

QUESTIONS.1) Which results are outside the normal range?

2) Based on these result, what might be the diagnosis?

3) What is the relationship between the appearance of ketones in urine and carbohydrate metabolism?

Answers:Glucose is extremely high, and ketones are abnormal, since they should be 0. However, they are very low. This would more than likely indicate diabetes (type I).

The presence of ketones in the urine indicates a shift from carbohydrate catabolism to fatty acid catabolism, since ketones are the end product of the FA pathway.

Glucose should never be present in this amount. The normal renal threshold for glucoe reabsorption is about 200mg/dL, and when stressed, it can reabsorb 300mG/dL. In cases of severe

hyperglycemia (i.e. type I diabetes), the renal reabsorption threshold is exceeded, and glucose spills into the urine. This Px probably has a very high blood sugar (600-800 or so), and is probably ill, with flu-like symptoms.

Other things to consider in diabetes: polyuria, polydipsia, polyphagia. Parents will say "he eats and eats and seems to be losing weight". Generally these Px present to the doctor in DKA, so proper management is imperative.

Nugget: Na+ is normally the major osmotic attractant of serum, but in extreme hyperglycmeic cases, glucose takes over, and the Px will look like they are hyponatremic. A calculation can be done to correct for this, and serum Na+ is usually elevated, due to the dehydrated state of the body.

Diabetes insipidus also presents with polyuria and glucosuria, but NO KETONES.

The following cases do not have answers, so discuss away!

Case 3: Patient A is an 8 year old European American girl who woke up one morning with a fever and complaining of back pain on the right side just above her waist. At the physician’s office later that morning on a clean catch, midstream urine sample, the following results were obtained.

Chemical/Physical AnalysisColor yellowClarity cloudySG 1.019pH 6.0Protein 1+Glucose negKetones negBlood 1+Bilirubin negUrobilinogen 0.1Nitrite posLeukocyte esterase 2+

Microscopic examination 40-60 WBC/hpf 0-8 RBC/hpf few squamous/lpf rare renal epithelial cell/hpf 3-6 WBC casts/hpf moderate bacteria

1. Are there any inconsistencies between the macroscopic, chemical and microscopic findings that need to be explained? If so, what might explain them?

2. What condition is indicated by this constellation of findings and which particular findings support this diagnosis?

3. Is any additional testing indicated for this patient? If yes, what test and what is its principle?

4. What is the source of the positive protein finding in this condition?

5. What is the purpose of assessing specific gravity in urine? Why is it important to know that the specific gravity was measured with a dipstik?

Case 4: Patient B is a 14 year old African American boy who had a sore throat about two weeks ago but that is now gone. His mother has taken him to an urgent care facility because his ankles and hands seems very swollen and his urine is dark. The following results are on a clean catch, midstream sample collected at the urgent care facility.

Chemical/Physical Analysis

Color brownClarity cloudySG 1.026pH 6.0Protein 3+Glucose negativeKetones negativeBlood 3+Bilirubin negativeUrobilinogen 0.1Nitrite negativeLeukocyte esterase negative

Microscopic examination 40-50 rbc/hpf3-10 WBC/hpf 0-5 hyaline casts/lpf0-2 rbc casts/lpf1-3 granular casts/lpffew sq. epi/hpf

1. Are there any inconsistencies between the macroscopic, chemical and microscopic findings that need to be explained? If so, what might explain them?

2. What condition is indicated by this constellation of findings and which particular findings support this diagnosis?

3. Is any additional testing indicated for this patient? If yes, what test and what is its principle?

4. What is the source of the positive protein finding in this condition?

5. Why are the patient’s ankles swelling?

6. What is the relationship of the patient’s prior sore throat to his present condition?

7. Why is the microscopic examination negative for bacteria?

Case 6: Patient C is an 18 year European American female who sought treatment at the university health center complaining of frequent urination with burning. She reported that she had sexual intercourse two days previous to this visit and had no recent history illness. She was instructed to collect a clean catch, midstream sample that was tested with the following results.

Chemical/Physical AnalysisColor yellowClarity cloudySG 1.012pH 5.5Protein 1+Glucose negativeKetones negativeBlood 1+Bilirubin negativeUrobilinogen 0.1Nitrite negativeLeukocyte esterase 2+

Microscopic examination 50-75 WBC/lpf some in clumps15-20 rbc/lpfmany sq epi/lpf 1+ mucous many bacteria

1. Are there any inconsistencies between the macroscopic, chemical and microscopic findings that need to be explained? If so, what might explain them?

2. What condition is indicated by this constellation of findings and which particular findings support this diagnosis?

3. Is any additional testing indicated for this patient? If yes, what test and what is its principle?

Case 6: Kenji is a 56 year old Asian American man who has been experiencing a sharp but intermittent pain in his back for some time. His wife has been pressing him to see a doctor but he has resisted until today because the pain has become more severe and persistent. Below are the results of a routine urinalysis on a clean catch midstream sample collected and tested in the physician office.

Chemical/Physical AnalysisColor yellowClarity clearSG 1.009pH 6.0Protein negativeGlucose negativeKetones negativeBlood traceBilirubin negativeUrobilinogen 0.1Nitrite negativeLeukocyte esterase negative

Microscopic examination 0-2 sq epi/lpf2-5 rbc/hpf 0-1 WBC/hpf

1. Is the sample acceptable for evaluation? Explain your conclusion.

2. Are there any inconsistencies between the macroscopic, chemical and microscopic findings that need to be explained? If so, what might explain them?

3. What condition is suggested by this constellation of findings and which particular findings support this diagnosis?

4. Is any additional testing indicated for this patient? If yes, what test and what is its principle?

Case 7: Obrian is an 8 year old African American boy who was hospitalized with pneumonia following a cold. He was treated with antibiotics and within a day of

beginning treatment, his urine turned dark. The results below are the from the second urine sample after the dark urine was discovered. A CBC collected shortly after the dark urine was reported showed an elevated white blood count with a left shift and toxic changes; normochromic, normocytic anemia with an occasional helmet cell and shistocyte; and normal platelet count and morphology.

Chemical/Physical AnalysisColor red-brownClarity clearSG 1.015pH 5.5Protein traceGlucose negativeKetones negativeBlood 4+Bilirubin negativeUrobilinogen negativeNitrite negativeLeukocyte esterase negative

1. Is the sample acceptable for evaluation? Explain your conclusion.

2. Are there any inconsistencies between the macroscopic, chemical and microscopic findings that need to be explained? If so, what might explain them?

3. What condition is suggested by this constellation of findings and which particular findings support this diagnosis?

4. Is any additional testing indicated for this patient? If yes, what test and what is its principle?

5. What changes to the results of the urinalysis would be expected in the next few days? What is the principle of the test on the stik that will detect these changes?

Case 8: Bobby Mcgee, a 56 year old white male, had some basic tests performed as part of an insurance policy screening. The urine sample was collected at the patient’s home and then delivered to a laboratory for testing and reporting. The sample was a random void without directions to collect it midstream or clean catch.

Chemical/Physical AnalysisColor yellowClarity hazySG 1.012pH 6.0Protein negative

Glucose negativeKetones negativeBlood negativeBilirubin negativeUrobilinogen 0.1Nitrite negativeLeukocyte esterase negative

Microscopic examination: moderate calcium oxalate crystals few bacteria

1. Is the sample acceptable for evaluation? Explain your conclusion.

2. Are there any inconsistencies between the macroscopic, chemical and microscopic findings that need to be explained? If so, what might explain them?

3. What condition is suggested by this constellation of findings and which particular findings support this diagnosis?

4. Is any additional testing indicated for this patient? If yes, what test and what is its principle?

5. Under what conditions are crystals seen in urine? Which crystals are considered normal?

Case 9: Harriet is a 40 year old African American woman who has been experiencing sharp pains under her ribs on the right side for several months. She seems to think that it is related to eating heavy meals. She has finally decided to see her physician because this morning when she woke up she noticed that her eyeballs had turned yellow and this was pretty scary to her. A urine sample collected in the physician’s office showed the results below.

Chemical/Physical AnalysisColor dark yellowClarity hazySG 1.020pH 5.5Protein negativeGlucose negativeKetones negativeBlood negativeBilirubin positiveUrobilinogen negativeNitrite negative

Leukocyte esterase negative

Microscopic examination moderate sq. epi/hpf

1. Is the sample acceptable for evaluation? Explain your conclusion.

2. Are there any inconsistencies between the macroscopic, chemical and microscopic findings that need to be explained? If so, what might explain them?

3. What condition is suggested by this constellation of findings and which particular findings support this diagnosis?

4. Is any additional testing indicated for this patient? If yes, what test and what is its principle?

Case 10: Bret is 18 month old European American boy seen in the doctor’s office for a routine well-child visit. The urine sample was collected with one of the pediatric bags.

Chemical/Physical AnalysisColor yellowClarity hazySG 1.013pH 6.5Protein negativeGlucose negativeKetones negativeBlood negativeBilirubin negativeUrobilinogen 0.1Nitrite negativeLeukocyte esterase negative

Microscopic examination 15-20 sq epis/lpf few uric acid crystals/lpf

1. Is the sample acceptable for evaluation? Explain your conclusion.

2. Which results are outside reference ranges or acceptable limits?

3. Are there any inconsistencies between the macroscopic, chemical and microscopic findings that need to be explained? If so, what might explain them?

4. What condition is suggested by this constellation of findings and which particular findings support this diagnosis?

5. Is any additional testing indicated for this patient? If yes, what test and what is its principle?

Case 11: Lilia, a 35 year old Mexican American woman, provided the urine sample whose results are below during a routine physical examination. She was instructed to provide a mid-stream sample. Her weight was down approximately 10 pounds from the prior year and she said she had been working out and eating more healthfully. She was found to be healthy.

Chemical/Physical AnalysisColor strawClarity clearSG 1.007pH 5.5Protein negativeGlucose negativeKetones 1+Blood negativeBilirubin negativeUrobilinogen 0.1-1.0 EUNitrite negativeLeukocyte esterase negative

Microscopic examination 0-2 sq epis/lpf

1. Is the sample acceptable for evaluation? Explain your conclusion.

2. Are there any inconsistencies between the macroscopic, chemical and microscopic findings that need to be explained? If so, what might explain them?

3. What condition is suggested by this constellation of findings and which particular findings support this diagnosis?

4. Is any additional testing indicated for this patient? If yes, what test and what is its principle?