Presentation on theme: "Stop…let Me A-”cyst” You"— Presentation transcript:
1 Stop…let Me A-”cyst” You A Case Study about Cystinuria by Amy Albright
2 Patient History 57 year old woman with history of renal problems Patient hospitalized upon urgent referral from doctor’s officeUrinalysis was performed
3 Urinalysis Results Test Patient Result Reference Range Color Yellow Clarity CloudyGlucose neg (negative)Bilirubin neg (negative)Ketones neg (negative)Sp. Gravity ( )Blood (negative)pH ( )Protein (negative)Urobilinogen ( )Nitrite neg (negative)Leuk. Esterase (negative)RBC (0-3)WBC (0-5)Epithelials (none)Hyaline cysts (<10)Bacteria (negative)Crystals cystine (negative)
4 Past Patient History Diagnosed with cystinuria as a child Left side nephrectomy as a child secondary to damage by cystine stonesRecurrent kidney stones in the remaining right kidneyNephrostomy tube placed intoremaining kidney
5 Questions to be Considered: 1.) How does the patient’s current renal problems relate to the cystine crystals found?2.) What laboratory tests are performed to confirm the presence of cystine crystals in the urine?3.) What are the long term effects of cystine crystal formation?4.) Are there treatments available for patients with cystinuria?
6 Pathogenesis of Cystinuria Autosomal recessive disorderInvolves a defect in the renal transport of cystine by the tubulesDefect results in lack of cystine reabsorbtion of the kidneyHomozygous patients usually the only ones to present with problemsHeterozygotes have a milder form of cystinuria (cystine crystals found in urine during analysis but don’t usually form stones)
7 Solubility within the Kidney Normal excretion of amino acids such as cystine into the urine is about 100 mg/dayHeterozygous excrete around mg/dayHomozygous excrete around mg/daySolubility limit is around mg/dayStones composed of cystine form when the concentration of cystine exceeds the normal solubility levels and the excess cannot go into solution (cystine crystals favor the existing free cystine and will compound it to form the stone)
8 Cystine Confirmation Initially found during a microscopic urinalysis crystals are found in neutral to acidic pH and are flat hexagonal shapesConfirmation test for cystine once crystals are found microscopically is a cyanide-nitroprusside testinvolves mixing the urine with sodium cyanide and then sodium nitroprusside which will chemically react to produce a red-purple color indicative of presence of cystine crystals in the urine
9 Positive Nitroprusside Reaction: Left side: Negative controlRight side: Positive for cystine
10 Long Term Effects of Cystinuria Recurrent stone formation as seen with this patientPossible nephrectomy due to renal failurePain associated with stone formation and passage
11 Treatments Focus is on management Relief of symptoms (pain medications)Prevention of further stones (drinking large amounts of water to dilute the urine)
12 Treatments - continued….. Watching diet ( avoiding methionine rich foods)Alkanization of the urine (use of sodium bicarbonate or sodium citrate to more readily dissolve the cystine)Lithotripsy (non-invasive, shock waves to break up the stone to where it can be passed)Invasive procedures for stone removal
13 Summary57 year old women with presence of cystine crystals in the urineConfirmatory nitroprusside test was positive for cystineHistory revealed many renal problems associated with cystinuriaTreatments are unpredictable
14 the 2004 MT Class at William Beaumont CreditsThis case study wasprepared byAmy Albright, MT(ASCP)while she was aMedical Technologystudent inthe 2004 MT Class at William BeaumontHospital, Royal Oak, MI.