What is the Los Angeles classification used for in gastroesophageal reflux disease (GERD) and how is it used to guide treatment?

Los Angeles Classification in GERD: Diagnosis and Treatment Guidance

The Los Angeles (LA) classification is a standardized endoscopic grading system for erosive esophagitis in GERD that directly guides treatment decisions, with LA Grade B or higher indicating conclusive GERD requiring optimized PPI therapy, while LA Grade A may represent borderline disease requiring additional diagnostic testing. 1

Classification System Overview

The Los Angeles classification categorizes erosive esophagitis into four grades based on the extent of visible mucosal breaks:

• Grade A: One or more mucosal breaks ≤5 mm in length that do not extend between the tops of two mucosal folds
• Grade B: One or more mucosal breaks >5 mm in length that do not extend between the tops of two mucosal folds
• Grade C: Mucosal breaks that extend between the tops of two or more mucosal folds, but involve less than 75% of the esophageal circumference
• Grade D: Mucosal breaks that involve at least 75% of the esophageal circumference

Diagnostic Significance

The LA classification provides objective evidence for GERD diagnosis:

• LA Grade B or higher: Constitutes conclusive evidence of GERD without need for additional testing 1, 2
• LA Grade A: Represents borderline GERD requiring additional diagnostic confirmation 1, 2
• Normal endoscopy: Requires pH monitoring to confirm GERD diagnosis 1

Recent research confirms that 100% of patients with LA Grade B esophagitis have objective GERD based on pH-impedance studies, comparable to LA Grade C (100%), while only 17.6% with LA Grade A have objective GERD 2.

Treatment Implications

The LA classification directly guides treatment decisions:

For LA Grade B or Higher:

• Optimize PPI therapy to control symptoms 1
• Implement aggressive lifestyle modifications including weight management 1
• Consider cognitive behavioral therapy or gut-directed hypnotherapy as adjunctive treatment 1

For LA Grade A:

• Consider additional testing with prolonged wireless pH monitoring off PPI therapy 1
• If pH monitoring confirms GERD (AET ≥4.0%), treat as borderline GERD with optimized PPI therapy 1
• If pH monitoring is negative (AET <4.0% on all days), consider functional esophageal disorder and discontinue PPI 1

For LA Grade C/D:

• These represent a severe GERD phenotype that may require more aggressive management 1
• May indicate need for long-term PPI therapy or consideration of anti-reflux procedures 1, 3

Clinical Pearls and Pitfalls

• Important distinction: LA Grade B esophagitis has recently been confirmed to represent conclusive GERD (100% objective GERD on pH testing), while LA Grade A often does not (only 17.6% have objective GERD) 2

• PPI response rates correlate with LA classification: Grade B (74%) and Grade C (70%) have similar response rates, while Grade A has significantly lower response (39%) 2

• LA Grade D has unique features: Unlike milder grades, LA Grade D primarily affects older, non-obese, hospitalized patients with serious comorbidities and often without typical GERD history, suggesting factors beyond typical GERD contribute to its pathogenesis 4

• Endoscopic grading reliability: Endoscopists can reliably identify mucosal breaks, but central adjudication may be needed in research settings for consistency 5, 6

• Esophageal motility correlation: Severity of reflux esophagitis according to LA classification correlates with decreased lower esophageal sphincter pressure and impaired esophageal clearance 7

Treatment Algorithm Based on LA Classification

1. LA Grade B or higher:

   • Optimize PPI therapy
   • Implement aggressive lifestyle modifications
   • If symptoms controlled: Wean to lowest effective dose or on-demand therapy
   • If symptoms uncontrolled: Consider pH-impedance monitoring on PPI therapy

2. LA Grade A:

   • Perform prolonged pH monitoring off PPI
   • If AET ≥4.0%: Treat as borderline GERD
   • If AET <4.0%: Consider functional disorder and discontinue PPI

3. Normal endoscopy:

   • Perform prolonged pH monitoring off PPI
   • Base treatment on pH results (AET <4.0% = No GERD; AET ≥6.0% on 2+ days = GERD)

The LA classification remains the cornerstone of objective GERD diagnosis, with Grade B or higher providing conclusive evidence of disease requiring appropriate acid-suppressive therapy.