What is the difference between reactive gastropathy and gastritis?

Distinguishing Reactive Gastropathy from Gastritis

Reactive gastropathy and gastritis are fundamentally different entities: reactive gastropathy represents a non-inflammatory mucosal response to chemical injury characterized by architectural changes with minimal inflammation, while gastritis is defined by the presence of significant mucosal inflammation. 1, 2

Key Histopathological Differences

Reactive Gastropathy (Chemical Gastropathy)

The hallmark of reactive gastropathy is the constellation of structural changes occurring in the absence of significant inflammation. 1 The diagnostic features include:

• Foveolar hyperplasia - elongation and tortuosity of gastric pits 1
• Interfoveolar smooth muscle fibers - smooth muscle extending into the lamina propria between foveolae 1
• Mucosal edema and hyperemia - vascular congestion and tissue swelling 1
• Erosions - epithelial defects that may be present 1
• Minimal to absent inflammatory infiltrate - this is the critical distinguishing feature 1, 2

Gastritis

Gastritis is fundamentally a histological diagnosis defined by the presence of mucosal inflammation. 2 The key features include:

• Significant inflammatory cell infiltration - presence of neutrophils (acute) or lymphocytes and plasma cells (chronic) 2
• Loss of gastric glands with or without metaplasia in chronic atrophic gastritis, typically due to Helicobacter pylori infection or autoimmunity 3
• Inflammatory etiology - most commonly infectious (acute) or H. pylori/autoimmune (chronic) 2

Clinical Context and Etiologies

Reactive Gastropathy Associations

Reactive gastropathy develops in response to chemical injury rather than infectious or immune-mediated processes. 1, 2 Common causes include:

• NSAID use - the most frequently identified etiology 4, 5
• Bile reflux - duodenogastric reflux causing chemical injury 4, 5
• Other inflammatory conditions throughout the GI tract - reactive gastropathy shows associations with Barrett's mucosa, duodenitis, ileitis, and microscopic colitis 5

Importantly, reactive gastropathy shows an age-dependent increase, rising from 2% in the first decade to over 20% in octogenarians, and is evenly distributed geographically 5.

Gastritis Associations

Chronic gastritis is primarily associated with H. pylori infection or autoimmune mechanisms. 3, 2 Interestingly, there is an inverse relationship between reactive gastropathy and H. pylori gastritis - conditions with reactive gastropathy (such as gastroparesis) show significantly lower rates of H. pylori infection 6.

Diagnostic Spectrum and Clinical Pitfalls

A critical caveat is that the diagnosis of reactive gastropathy exists on a spectrum of certainty that is never absolute. 1 Each histological feature can occur in other conditions, making the diagnosis one of pattern recognition rather than pathognomonic findings.

Important Considerations:

• Mucin expression patterns differ between reactive gastropathy and H. pylori gastritis, with reactive gastropathy showing loss of MUC1 (67% of cases) and aberrant MUC5AC expression (81% of cases) 4
• The severity of architectural changes in reactive gastropathy can be graded as mild, moderate, or severe, with more severe changes showing more extensive mucin alterations 4
• Multiple etiologies can produce similar appearances - NSAIDs and bile reflux both cause reactive gastropathy with similar histological features, underscoring its nonspecific nature 4

Clinical Implications

While reactive gastropathy lacks the inflammatory component that defines gastritis, both conditions require histopathological confirmation for accurate diagnosis. 3, 1 The distinction matters clinically because:

• Treatment approaches differ fundamentally - reactive gastropathy requires identification and removal of the offending agent (NSAIDs, bile reflux), while gastritis may require antimicrobial therapy (H. pylori) or immunosuppression (autoimmune) 2
• Prognosis differs - atrophic gastritis represents a preneoplastic condition requiring surveillance, while reactive gastropathy's cancer risk is not well-established 3
• The presence of reactive gastropathy should prompt clinician review of medications that might benefit from modification or discontinuation 1