Table 1 Schistosoma japonicum-induced liver granuloma stages and inflammation

I. The pre-granulomatous stage—mini size, early inflammation (stage a)

a. Minimal disorganized aggregation of immune cells

b. No fibroblasts or extracellular matrix, no collagen fibers

c. Few eggs deposited

II. The granulomatous stages

(1) Early stage—small size, acute inflammation (stage b)

a. Infiltration of organized immune cells including monocytes, eosinophils, etc., around eggs

b. No fibroblasts or collagen fibers, with few or without extracellular matrix

c. Many eggs deposited

Note: Stage b1: several organized immune cell infiltration; stage b2: many organized immune cell infiltration, without or with few extracellular matrix

(2) Mature stage—big size, chronic and fibrotic inflammation (stage c)

a. Clear outer granuloma rim which is composed of a dense population of immune cells

b. Many recruited fibroblasts and their products including apparent extracellular matrix and collagen fibers inside the granuloma

c. Live or dead miracidium within the deposited eggs

(3) Late stage—small size, recovery (stage d)

Some pigmented macrophage infiltration

Disintegrated granuloma structure

Dead and calcified eggs