Histochemical studies on rectal mucosa in active intestinal schistosomiasis

Area of Science:

• Medical Parasitology
• Gastroenterology
• Histopathology

Background:

• Intestinal schistosomiasis mansoni (S. mansoni) is a significant public health concern.
• Understanding the histopathological and histochemical changes in the rectal mucosa is crucial for disease staging and management.

Purpose of the Study:

• To investigate the histopathological and histochemical alterations in the rectal mucosa of patients with varying stages of intestinal S. mansoni infection.
• To correlate these changes with disease severity and parasite burden.

Main Methods:

• Histopathological examination of rectal biopsies from 30 S. mansoni infected patients (categorized into early, hepatosplenomegalic, and ascitic groups) and 10 controls.
• Histochemical staining (Periodic Acid Schiff, Alkaline Phosphatase, Acetylcholinesterase) to assess mucin content, enzyme activity, and nerve fiber integrity.
• Correlation of findings with clinical presentation (hepatosplenomegaly, ascites) and infection intensity.

Main Results:

• Early S. mansoni infection showed hyperaemia and extravasation of blood; later stages exhibited granulomatous lesions and severe structural changes, including distorted mucosal glands.
• Periodic Acid Schiff staining revealed reduced neutral mucin in goblet cells of advanced (ascitic) cases, with intensity varying by infection load.
• Alkaline phosphatase was localized to S. mansoni eggshells, not rectal crypts. Acetylcholinesterase staining showed a significant decrease in nerve fibers, more pronounced in chronic and heavily infected patients.

Conclusions:

• Histopathological and histochemical changes in the rectal mucosa reflect the progression of intestinal S. mansoni infection.
• Goblet cell mucin depletion and reduced acetylcholinesterase activity in nerve fibers are indicators of advanced disease and higher parasite burden.
• These findings highlight the utility of rectal mucosal analysis in assessing schistosomiasis severity and its pathological impact.