Autosomal Dominant Polycystic Kidney Disease in a 30-Year-Old Man

A 30-year-old man presentedwith severe left flankpain radiating to his abdomenand gross hematuriaof 5 to 10 days' duration.He also reported a 4- to 6-monthhistory of nausea with intermittentvomiting, anorexia, and progressiveweight loss. He took no medicationsand had no allergies.Blood pressure was 164/103mm Hg; heart rate, 124 beats perminute; and temperature, 39.2C(102.5F). Auscultation revealed agrade 2/6 systolic heart murmur andminimal bibasilar lung crackles. Thepatient's abdomen was distended; palpationdisclosed bilateral abdominalmasses.Sodium level was 137 mEq/L;potassium, 4.2 mEq/L; bicarbonate,17.5 mEq/L; and chloride,106 mEq/L. Blood urea nitrogen levelwas 68 mg/dL; serum creatinine,8.3 mg/dL; hemoglobin, 5.1 g/dL;and hematocrit, 15.5%. Urinalysis wasnotable for specific gravity of 1.009,2+ protein, more than 20 red bloodcells per high-power field, and 6 to 10white blood cells per high-powerfield.The patient was admitted to theICU. A CT scan of the abdomen revealedmassive bilateral polycystickidneys with an area of hemorrhageand possible infection within the cysts(arrow).Ursula C. Brewster, MD, of NewHaven, Conn, diagnosed autosomaldominant polycystic kidney disease(ADPKD), the most common hereditaryrenal disease and the fourthmost common cause of end-stagerenal disease. From 1 in 400 to 1 in1000 Americans are affected.¹Mutations in 3 different genescan account for its development. ThePKD1 gene--which is responsible forADPKD1, the most common disorder--is present on the short arm ofchromosome 16. The PKD2 gene islocated on chromosome 4, and thechromosomal location of PKD3 hasnot been determined.Although multiple organs are involved,ADPKD is predominantly arenal disorder with various clinicalmanifestations. Kidney involvementconsists mainly of formation of numerouscysts of varying size. This leads toan increase in kidney size and sometimesto massive nephromegaly. Complicationsof renal cysts include hypertension,nephrolithiasis, renal failure,hematuria, and acute or chronic flankpain. Acute clinical manifestations, asseen in this patient, can develop fromrupture, hemorrhage, or infection ofthe cyst. It is often difficult to distinguishthese various processes withoutrenal imaging. A CT scan can visualizehemorrhagic cysts, fluid-filledcysts, and cyst rupture; however, determinationof infection within a cystis difficult.Treatment of cyst rupture andhemorrhage is supportive and includespain control, red blood celltransfusions, and correction of anyunderlying coagulopathies. Rarely, apatient may require nephrectomy.Cyst infection is treated with antibiotics(ciprofloxacin, trimethoprim-sulfamethoxazole,or chloramphenicol)that penetrate the cyst and accumulatein cyst fluid. Cyst drainage israrely required to resolve infection.This patient was treated with intravenousciprofloxacin for possiblecyst infection. Three units of packedred blood cells was transfused, andsubcutaneous erythropoietin therapywas initiated. The patient's flank painand fever eventually resolved, and thehematocrit stabilized. Renal replacementtherapy was started. The patientremains dependent on dialysis.

References:

REFERENCE:

1.

Wilson PD. Polycystic kidney disease.

N Engl JMed.

2004;350:151-164.