Can posterior reversible encephalopathy syndrome be associated with elevated serum creatinine and abnormal liver function tests?

Can PRES Present with Elevated Creatinine and Abnormal Liver Function Tests?

Yes, posterior reversible encephalopathy syndrome (PRES) can absolutely be associated with elevated serum creatinine and deranged liver function tests, as these often reflect the underlying systemic conditions that precipitate PRES rather than direct effects of the syndrome itself.

Understanding the Association

PRES does not directly cause renal or hepatic dysfunction. However, the clinical contexts in which PRES develops frequently involve multi-organ involvement:

Renal Dysfunction in PRES

Elevated creatinine is commonly seen with PRES because renal failure is a well-established risk factor for the syndrome 1. The evidence demonstrates:

• In eclampsia-associated PRES, serum creatinine ≥1.2 mg/dL was an independent predictor (adjusted OR 2.86, p=0.008), and acute kidney injury occurred significantly more frequently in patients with PRES 2
• A retrospective analysis of post-transplant PRES identified serum creatinine increased two-fold from baseline as the only risk factor for developing PRES after allogeneic stem cell transplantation 3
• In malignant hypertension with PRES, renal impairment with creatinine >1.7 mg/dL is part of the diagnostic criteria for acute fatty liver of pregnancy, which can coexist with PRES 4
• End-stage renal disease is a recognized risk factor, with documented cases of recurrent PRES in patients on hemodialysis 5, 6

Liver Function Test Abnormalities in PRES

Deranged LFTs occur in PRES when it develops in the context of hepatic disease or preeclampsia/HELLP syndrome:

• In eclampsia with PRES, the underlying preeclampsia spectrum includes HELLP syndrome (hemolysis, elevated liver enzymes, low platelets), which by definition involves elevated transaminases 7, 8
• PRES has been documented in alcoholic hepatitis with hepatic encephalopathy 9 and in valproate-induced acute liver failure 10, demonstrating that severe hepatic dysfunction can coexist with PRES
• The hypertensive disorders of pregnancy guideline recommends checking liver enzymes (AST, ALT, LDH) and function tests (INR, bilirubin, albumin) as baseline tests, as these are frequently abnormal in preeclampsia complicated by PRES 7
• In acute fatty liver of pregnancy, which can present with PRES-like features, elevated transaminases (>42 IU/L), elevated bilirubin (>0.8 mg/dL), and coagulopathy are diagnostic criteria 4

Clinical Algorithm for Evaluation

When encountering a patient with suspected PRES:

1. Check both renal and hepatic function immediately - these are not exclusion criteria but rather help identify the precipitating condition

2. Look for the underlying systemic disorder:

   • Severe hypertension (especially BP ≥170 mmHg systolic) 2
   • Preeclampsia/eclampsia with proteinuria and thrombocytopenia 7, 2
   • Renal failure (acute or chronic) 5, 3, 6
   • Immunosuppressive drug toxicity (tacrolimus, cyclosporine) 3, 11
   • Hepatic encephalopathy 9, 10

3. Obtain complete laboratory panel:

   • Hemoglobin, platelet count (thrombocytopenia <100×10³/μL is a predictor) 2
   • Creatinine, electrolytes, uric acid 7
   • AST, ALT, LDH, bilirubin, albumin, INR 7, 4
   • Urinalysis for proteinuria 7

4. Confirm PRES with MRI showing characteristic T2/FLAIR hyperintensities in posterior circulation (though atypical distributions including brainstem and spinal cord can occur) 1, 5, 6

Critical Pitfalls to Avoid

• Do not dismiss PRES because creatinine or LFTs are elevated - these abnormalities often indicate the precipitating condition (preeclampsia, renal failure, hepatic disease) that caused PRES
• Do not confuse PRES with primary hepatic encephalopathy - while both can occur in liver disease 9, PRES has distinct radiographic findings and responds to blood pressure control rather than ammonia-lowering therapy
• Do not delay treatment waiting for "normal" labs - PRES requires urgent blood pressure management regardless of renal or hepatic function 1, 2
• In pregnancy, recognize that HELLP syndrome represents severe preeclampsia and commonly presents with both elevated LFTs and PRES 7, 8, 12

The key principle: PRES is a clinical-radiological syndrome that occurs in the setting of systemic illness. Elevated creatinine and abnormal LFTs are markers of the underlying precipitating conditions (hypertensive emergency, preeclampsia, renal failure, hepatic disease) rather than contraindications to the diagnosis.