Urinalysis

A urinalysis is exactly what the name entails. An analysis of a patients urine. A urinalysis is a fairly common test that may be ordered as part of an annual physical or part of diagnostic testing. It can be used as an evaluation of UTIs, Diabetes Mellitus, kidney disease, kidney stones, proteinuria, rhabdomyolysis, liver disease, or if a patient presents with particular symptoms such as abdominal pain, flank pain, painful urination, blood upon urination, and fever. Pregnancy testing is also part of a routine urinalysis if ordered.

The first step in an urinalysis is collection of the specimen from the patient. An optimal sample is an early morning sample, as it is the most concentrated produced during the day. There are no fasting requirements or medication schedule dosage changes unless otherwise directed by the patients ordering physician. 30-60 mL of urine is collected in a clean urine specimen cup through a clean catch method that should be explained to the patient upon request of sample.

There are different variants of urinalysis. One is the macroscopic observation of the urine. This is the direct visual observation which includes noting its quantity, clarity, and color. Urine is normally yellow and clear without any cloudiness. Abnormalities can mean different things and further analysis is needed.

Cloudy: Infection

Dark Yellow: Dehydration

Brown: Liver disease (caused by an accumulation of bilirubin)

Red: Blood (Indicates UTI, stones, tumors, renal trauma)

Orange/Tea Colored: Rhabdomyelitis (Breakdown of muscle)

Foamy: May suggest excess protein

It is important to note that certain medications taken for UTIs can change the color of the urine, Phenazopyridine in particular.

Macroscopic -Urinalysis

Dipstick chemical analysis is performed on a narrow plastic strip which has individual tests denoted with different colored squares. The entire strip is dipped into the urine sample and color changes of the squares are noted either by the technologist or by inserting it into an instrument to read it. Each square takes a specific amount of time to react so its important to allow the reaction to come to fruition before resulting. The color change of particular squares are compared to a reference guide and can point out abnormalities.

In no particular order the squares on the dipstick indicate;

Specific gravity (concentration of the urine)

pH

Protein concentration

Glucose concentration

Presence of Ketones

Hemoglobin

Leukocyte esterase (Suggestive of WBC in urine)

Nitrite (Suggestive of bacteria in urine)

Bilirubin

Urobilinogen

Multistix-Urinalysis-Color-Key

Dipsticks are convenient and are easy to interpret and cost-effective. Its important to keep in mind that dipsticks are qualitative and not quantitative in that they only suggest that there is an abnormality, they don’t quantify that abnormality. Further analysis is required for such results.

Microscopic analysis can detect cells, cellular debris, bacteria, crystals, and certain casts to confirm the dipstick results and further quantify analysis. Once the samples are received they must be centrifuged and discarding the supernatant. Epithelial cells may suggest inflammation or damage to the gallbladder and casts and cellular debris suggest inflammation of the kidneys and upper urinary tract. On very rare occasions tumor cells can be seen which are diagnostic for certain renal carcinomas and other urinary tract cancers.

If red cells are noted it could indicate either an infection, trauma, or stones. They can also indicate glomerulonephritis which is inflammation of the kidneys. Sometimes small amounts of red cells will be seen in healthy individuals.

Urine is considered a sterile body fluid therefore there should be no white blood cells or bacteria. Any amount of WBC or bacteria within the urine is considered abnormal and is suggestive of an UTI, cystitis, or pyelonephritis.

Identifying crystals if any is important and lend diagnostic information as to what is pathologically going on within the body.

Uric acid crystals can vary in size and shape, but usually resemble a rhomboid shape. These crystals are common in individuals with urate nephrolithiasis or acute urate nephropathy.

65d7e43a5a15159700b0580d43898a44a87736d5-uacystalsurineweb

Cystine crystals are usually colorless hexagonally shaped and look similar to benzene rings (bringing it back to organic chemistry days). These occur in patients with cystinuria which is a genetic defect in renal cystine transport and in acidic urine (pH <6.0).

FullSizeRender+13

Struvite crystals are often described as having a coffin-lid appearance. These crystals are typically magnesium ammonium phosphate and are seen in alkaline urine (pH >7.0). Seen in patients with UTIs caused by urea-splitting bacteria (Proteus mirabilis) or in patients with infected calculi (struvite stones).

fdfdsf

Calcium oxalate crystals are typically found in acidic urine and can take on multiple shapes. Some may look like colorless ovoids, biconcave discs, or even rods. Usually seen in patients with high dietary oxalate ingestion, patients with nephrolithiasis or those in ethylene glycol toxicity with renal failure.

Triple-phosphate-crystal

These are some of the more common crystals that will be seen. Urinalysis isn’t flashy and isn’t always fun as it is someones urine, but it is an important part of routine testing to better deliver care to the patient.

-Caleb

 

 

Advertisements

Presence of Thermally Dimorphic Organism with Microconidia/Macroconidia in Immunocompromised Patient

A bone marrow sample obtained from an immunocompromised patient revealed small intracellular cells using a Wright’s stain preparation. Growth on Sabouraud-dextrose agar plates of a mold phase at 25 degrees Celsius and a yeast phase at 37 degrees Celsius designates the organism as dimorphic. The mold phase produced thick, spherical tuberculated macroconidia. What is the most likely identification?


histo-microscopy

Initial clues point towards some sort of systemic organism of fungi origin. Growth at both 25 and 37 degrees confirms dimorphism which is important for the differential diagnosis.

Microscopy examination revealed macroconidia indicative of Histoplasma capsulatum. When all other information is taken into consideration, a diagnosis H. capsulatum seems most plausible.

Histoplasma capsulatum is mostly found in its natural setting in the soil. It is endemic in the Ohio and Mississippi river valleys, and in some parts of South America as well. Transmission of the mycosis occurs through inhalation of aerosolized microconidia with activity that disturbs the natural environment. The severity of the illness depends on the host immunity status coupled with the intensity of the exposure. Only 1% of infections are symptomatic.

In this case the patient was immunocompromised. There are three distinct courses the disease can take depending on the immune status of the host. Acute primary histoplasmosis is typically a self-limiting disease. Localized to the lung and the patient may experience fever, cough, chest pain, and malaise (general unwell). Chronic cavitary histoplasmosis is characterized by atypical pulmonary lesions that resemble tuberculosis. Progression can lead to disabling respiratory dysfunction. Progressive disseminated histoplasmosis is generalized involvement of the RES with hepatosplenomegaly, lymphadenopathy, bone marrow involvement, with sometimes GI involvement.

The yeast form is able to survive within circulating monocytes and tissue macrophages. This is the primary way that the fungi disseminates. When H. capsulatum converts to the yeast form, it expresses proteins that interact with the phagocytic receptors on the macrophage surface. These interactions allow entry into the macrophage without activating it to undergo phagocytosis.

Treatment for the patient mentioned above should include amphotericin B including combinations of both liposomal and lipid formulations as well as itraconazole. Amphotericin B binds to ergosterol which is a component of fungal cell membranes. This causes pores to form in the membrane causing leakage of the monovalent ions K+, Na+, H+ and Cl- which subsequently induces fungal cell death.

-Caleb