MKSAP Quiz: generalized malaise and fatigue
Rehab with optional later knee surgery works for ACL tears
A 52-year-old woman is evaluated for a 6-week history of generalized malaise and fatigue. She received a kidney transplant 15 years ago for hypertension-related renal failure. Her current medications include cyclosporine and azathioprine.
The vital signs and general physical examination are normal.
Complete blood count is normal. The blood urea nitrogen level is 56 mg/dL (20 mmol/L), and the serum creatinine level is 3.0 mg/dL (265.2 µmol/L) compared with a value 2 months ago of 1.7 mg/dL (150.3 µmol/L). Urinalysis is significant for 19 leukocytes/hpf, no erythrocytes, 2+ protein, and many squamous and renal tubular epithelial cells, some of which have intranuclear inclusions.
Infection with which of following is the most likely cause of this patient's worsening kidney function?
A. Cytomegalovirus
B. Epstein-Barr virus
C. Human herpesvirus-8
D. Polyomavirus BK virus
E. Polyomavirus JC virus
MKSAP Answer and Critique
The correct answer is D) Polyomavirus BK virus. This item is available to online to MKSAP 15 subscribers as item 47 in the Infectious Diseases module
This presentation is typical for polyomavirus BK virus–induced nephropathy in a patient with a transplanted kidney. Polyomavirus BK virus is acquired asymptomatically early in childhood by as many as 90% of all persons. The virus persists throughout life but rarely causes problems in normal hosts. However, it may result in serious disorders in immunosuppressed patients and is an important cause of kidney allograft failure. The virus may be reactivated in 30% or more of kidney transplant recipients as evidenced by shedding of “decoy cells” (tubular or transitional cells with intranuclear viral inclusions) or viremia, which may be characterized by fatigue, myalgia, and malaise. Further confirmation can be obtained by identifying the virus in urine or blood or by kidney biopsy, which is the gold-standard diagnostic test. Quantification of the virus is useful in assessing and managing the effects of treatment, which may include reducing immunosuppressive therapy or using experimental medications, such as leflunomide, cidofovir, or fluoroquinolones.
After the first posttransplantation month, cytomegalovirus (CMV) is one of the infectious agents most likely to affect graft survival and cause life-threatening complications. CMV infection typically involves the gastrointestinal tract and is associated with fever, pain, ulcerations, and hepatitis. CMV alone does not lead to nephropathy, although it may have additive effects in the presence of the BK virus.
The Epstein-Barr virus may cause posttransplantation lymphoproliferative disease, but it is not known to cause nephropathy. Posttransplantation lymphoproliferative disease is characterized by symptoms suggestive of infectious mononucleosis followed by a progressive deteriorating course that may involve the brain, liver, bone marrow, and transplanted organ.
Human herpesvirus-8 infection causes Kaposi sarcoma and is associated with Castleman disease and primary effusion lymphoma but does not appear to cause hepatitis, encephalitis, or nephropathy.
Polyomavirus JC virus may cause progressive multifocal leukoencephalopathy but not renal disease in patients with transplanted kidneys.
Key Point
- Polyomavirus BK virus is a common cause of nephropathy in patients with transplanted kidneys.