PALBI Score

Platelet-Albumin-Bilirubin Grade — Refined Liver Function Grading
Refined liver function grading incorporating platelet count for improved prognostic discrimination in HCC and cirrhosis. Subdivides ALBI Grade 2 into 2a and 2b, particularly useful in thrombocytopenic patients with portal hypertension.
Hepatology HCC Cirrhosis Portal Hypertension
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Formula

PALBI = −2.53 × log₁₀(Platelet ×10⁹/L)
         + 2.02 × log₁₀(Bilirubin μmol/L)
         − 0.37 × (Albumin g/L)² × 0.01
         − 3.48 × log₁₀(Albumin g/L)
         + 1.01

Derived by Toyoda et al. (2016). Bilirubin must be entered in μmol/L. Platelet count in ×10⁹/L (i.e., standard units as reported on a full blood count). Albumin in g/L.

Interpretation

Grade PALBI Range Classification Clinical Implication
Grade 1 ≤ −2.53 Well-compensated Curative options appropriate
Grade 2a −2.53 to −2.09 Mild dysfunction Locoregional therapies feasible
Grade 2b −2.09 to −1.74 Moderate dysfunction Careful selection required
Grade 3 > −1.74 Significant dysfunction Systemic or supportive care

Relationship to ALBI Score

The PALBI score was developed as a refinement of the two-variable ALBI score, addressing a known limitation: ALBI Grade 2 encompasses a broad and heterogeneous range of liver function that spans from mild dysfunction (ALBI just below −2.60) to moderate-severe impairment (approaching −1.39). This wide range includes patients with substantially different prognoses and treatment tolerances who are all labelled identically.

By incorporating platelet count — a surrogate marker for portal hypertension and hypersplenism, reflecting the degree of hepatic fibrosis and sinusoidal resistance — PALBI introduces an additional dimension of liver-related morbidity not captured by bilirubin and albumin alone. Thrombocytopenia in cirrhosis reflects both reduced thrombopoietin production by the liver and increased platelet sequestration in the spleen secondary to portal hypertension, making it an indirect but clinically meaningful marker of disease burden.

The net effect is that PALBI subdivides ALBI Grade 2 into Grade 2a (mild dysfunction, closer to Grade 1 in prognosis) and Grade 2b (moderate dysfunction, closer to Grade 3 in outcomes), providing four distinct prognostic strata compared to ALBI's three. This subdivision is particularly relevant when selecting between transarterial chemoembolisation (TACE), systemic therapy, or best supportive care in the intermediate-stage HCC population.

Clinical Application

PALBI grade is applied in the same clinical context as ALBI grade — primarily as an objective liver function assessment tool in patients with hepatocellular carcinoma (HCC). It is used alongside tumour staging systems (BCLC staging) to determine appropriateness and expected tolerance of curative resection, transplantation, ablation, TACE, hepatic arterial infusion chemotherapy, or systemic therapy (sorafenib, lenvatinib, atezolizumab-bevacizumab, durvalumab-tremelimumab).

PALBI Grade 1 patients have preserved liver function and generally tolerate all treatment modalities. Grade 2a patients are suitable for locoregional therapies with careful monitoring. Grade 2b patients represent a more nuanced group where transarterial therapies carry higher risk of post-TACE liver failure, and systemic therapy may be preferable depending on tumour burden and performance status. Grade 3 patients have significant liver dysfunction, and treatment options are limited to systemic therapy (if Child-Pugh A/B) or best supportive care.

PALBI is also used to assess prognosis and guide surveillance intensity in non-HCC cirrhotic patients, particularly those with thrombocytopenia as a marker of clinically significant portal hypertension. The incorporation of platelet count makes it sensitive to changes in portal pressure over time or in response to treatment (e.g., non-selective beta-blockers, TIPS, antiviral therapy in hepatitis B/C).

Limitations

  • Requires three laboratory values versus ALBI's two; marginal increase in complexity at the point of care
  • Platelet count may be falsely low due to non-hepatic causes of thrombocytopenia (immune thrombocytopenia, haematological malignancy, medication effect) — these confounders are not accounted for in the score
  • Bilirubin must be entered in μmol/L; unit conversion errors are a potential patient safety issue
  • Validated primarily in HCC cohorts; evidence base in non-HCC liver diseases is less robust than for ALBI or Child-Pugh
  • Does not incorporate prothrombin time/INR, creatinine, or sodium — variables captured by MELD and relevant to waitlist prioritisation and acute-on-chronic liver failure
  • Clinical uptake remains lower than ALBI due to the longer formula and later validation; many published trial protocols and guidelines still reference Child-Pugh class or ALBI grade as primary eligibility criteria
  • The squared albumin term (albumin² × 0.01) makes the formula non-intuitive and harder to calculate mentally at the bedside

References

  1. Toyoda H, Tada T, Tsuji K, et al. A new simple scoring system predicting significant liver dysfunction after resection of hepatocellular carcinoma. J Hepatol. 2011;55(6):1259–1265.
  2. Toyoda H, Lai PBS, O'Beirne J, et al. Long-term impact of liver function on curative therapy for hepatocellular carcinoma: application of the ALBI grade. Br J Cancer. 2016;114(7):744–750.
  3. Toyoda H, Huang DQ, Nguyen MH. The PALBI and ALBI grades: new tools for assessing liver function and prognosis in patients with HCC and chronic liver disease. J Clin Med.
  4. Chan AWH, Chan SL, Mo FKF, et al. Albumin-to-alkaline phosphatase ratio: a novel prognostic index for hepatocellular carcinoma. Dis Markers. 2015;2015:564057.
  5. Pinato DJ, Sharma R, Allara E, et al. The ALBI grade provides objective hepatic reserve estimation across each BCLC stage of hepatocellular carcinoma. J Hepatol. 2017;66(2):338–346.