The Albumin-Bilirubin (ALBI) score is a modern, evidence-based tool that assesses liver dysfunction and predicts the long-term prognosis for individuals with liver disease. Initially developed for patients with hepatocellular carcinoma (HCC), the most common type of liver cancer, it provides an objective measure of liver health. This index distills the complex functions of the liver into a single, straightforward numerical value. The ALBI score helps healthcare providers reliably gauge a patient’s liver reserve function, guiding treatment decisions and predicting survival.
The Two Essential Components
The ALBI score relies on just two widely available laboratory values: serum albumin and total bilirubin. Albumin is a protein synthesized exclusively by the liver, making its serum concentration a direct reflection of the organ’s synthetic capacity. When the liver is significantly damaged, its ability to produce albumin decreases, leading to lower levels in the bloodstream.
Total bilirubin indicates the liver’s excretory function. Bilirubin is a yellow pigment that forms when old red blood cells are broken down, and a healthy liver is responsible for clearing this waste product from the body. An elevated total bilirubin level suggests the liver is struggling to process and excrete waste effectively. By combining these two objective measures of the liver’s dual role—synthesis and excretion—the ALBI score creates a robust measure of functional reserve.
Determining the ALBI Score
The ALBI score uses a precise mathematical formula to combine the two laboratory values. This formula calculates a single numerical index using the total bilirubin concentration, measured in micromoles per liter (\(\mu\text{mol/L}\)), and the serum albumin concentration, measured in grams per liter (\(\text{g/L}\)). The calculation involves multiplying the natural logarithm of the bilirubin value by a specific coefficient and adding the product of the albumin value and its own coefficient.
The specific mathematical expression ensures the resulting score is a continuous and objective index, which is a significant advancement over older, more subjective grading systems. This approach allows for a highly granular assessment, detecting small changes in liver function that simpler classifications might miss. The numerical result, which typically falls within a negative range, is the patient’s personalized ALBI score.
Interpreting the ALBI Grades
The calculated numerical ALBI score is translated into one of three clinical categories known as ALBI Grades, which are directly correlated with the patient’s liver reserve and predicted prognosis. A score of \(\le -2.60\) places a patient in ALBI Grade 1, indicating the best-preserved liver function and the best overall prognosis.
The intermediate category is ALBI Grade 2, assigned to scores ranging from \(>-2.60\) to \(\le -1.39\). This grade signifies a moderate impairment of liver function. Individuals in this group have a significantly worse prognosis than Grade 1 patients, reflecting a meaningful degree of functional compromise that requires careful therapeutic planning.
The most severe category is ALBI Grade 3, which includes any score \(>-1.39\). This grade indicates the most significant liver impairment and is associated with the poorest prognosis. Patients categorized as Grade 3 often face advanced liver disease. The clear stratification provided by these three grades allows clinicians to make informed decisions about the aggressiveness of treatment, particularly for conditions like liver cancer where liver function is the primary factor limiting therapeutic options.
Advantages Over Traditional Liver Assessment
The ALBI score was developed as a direct response to the limitations of older systems, such as the widely used Child-Pugh (CP) classification. One of the primary advantages of the ALBI score is its complete objectivity, as it relies solely on two verifiable laboratory values: albumin and bilirubin. The CP system, by contrast, incorporates variables like the degree of ascites (fluid accumulation) and hepatic encephalopathy (brain dysfunction), which are subjective and can vary based on a clinician’s judgment.
The ALBI score has demonstrated greater sensitivity, particularly in patients who appear to have good liver function based on older assessment methods. Many patients are classified as Child-Pugh Class A, yet the ALBI score can successfully divide this seemingly uniform group into distinct prognostic subgroups, often separating them into ALBI Grade 1 and ALBI Grade 2. This ability to identify subtle differences in liver reserve allows for more personalized treatment strategies for liver cancer, such as determining eligibility for surgery or other intensive therapies. The continuous, purely data-driven nature of the ALBI score makes it a superior tool for monitoring small changes in liver health over time.