What are the Los Angeles classification grades for reflux esophagitis?

Los Angeles (LA) Classification for Reflux Esophagitis

The Los Angeles classification is the standard endoscopic grading system for erosive reflux esophagitis, consisting of four grades (A through D) based on the extent and characteristics of esophageal mucosal breaks. 1

The Four Grades

Grade A

• One or more mucosal breaks ≤5 mm in length that do not extend between the tops of two mucosal folds
• Considered mild esophagitis
• Important caveat: LA Grade A can be seen in healthy asymptomatic volunteers and is not considered definitive evidence of erosive reflux disease 1
• Classified as "borderline GERD" when combined with acid exposure time (AET) ≥4.0% but not meeting full GERD criteria 1

Grade B

• One or more mucosal breaks >5 mm in length that do not extend between the tops of two mucosal folds
• Grade B or higher constitutes conclusive GERD evidence when found on endoscopy 1
• Requires optimization of PPI therapy to control symptoms 1

Grade C

• Mucosal breaks that extend between the tops of two or more mucosal folds but involve less than 75% of the esophageal circumference
• Considered severe erosive disease along with Grade D 1
• Associated with predominant nocturnal acid reflux and longer nocturnal acid clearance 2
• Patients typically have lower resting LES pressure and higher frequency of failed peristalsis 3

Grade D

• Mucosal breaks involving ≥75% of the esophageal circumference
• Most severe form of erosive esophagitis
• Indicates severe GERD phenotype requiring either continuous long-term PPI therapy or consideration of anti-reflux intervention 1
• Associated with extreme acid exposure (AET >12.0% or DeMeester Score ≥50) and often large hiatal hernias 1

Clinical Significance by Grade

Grades C and D represent a distinct pathophysiologic phenotype compared to lower grades:

• Transverse mucosal breaks predominantly in the posterior esophageal wall (versus longitudinal breaks in right-anterior wall for Grades A/B) 4
• Significantly higher prevalence and larger hiatal hernias 4
• Predominantly nocturnal gastroesophageal reflux versus daytime reflux in Grade A 2
• More likely to be refractory to standard PPI therapy due to nocturnal acid breakthrough 2

Common Pitfalls

1. Do not over-interpret Grade A esophagitis - it lacks specificity for GERD and requires correlation with symptoms and/or prolonged pH monitoring 1

2. Complete endoscopic documentation should include not just LA grade but also: Hill grade of flap valve, hiatal hernia length, and Barrett's esophagus assessment (Prague classification if present) 1

3. Inter-observer variability exists - agreement is only moderate even among specialists (κ = 0.425), with lower agreement among less experienced endoscopists 5

4. Grade determines management intensity: Grades C/D require indefinite PPI therapy or anti-reflux intervention, while lower grades may be weaned to on-demand therapy after symptom control 1