Table III.

Characteristics of pathological changes found in animal models of infectious, inflammatory and autoimmune male factor infertility and their occurrence in respective human disorders.

Pathology		Animal models					Human disease
		Bacterial epididymitis / epididymo-orchitis	Systemic viral disease	LPS-induced inflammation	EAO	Vasectomy	Bacterial epididymitis / epididymo-orchitis	Systemic infection (i.e. viral disease)	Testicular inflammatory lesions in infertile males
Semen quality	Impaired sperm parameters/azoospermia	+	nd	nd	+	+	+	+	+
	Leukocytospermia	nd	nd	nd	nd	–	+	–	–
Detection of pathogens	Epididymis (caput)	+	nd	–	–	–	+	+	–
	Testis	(+)	+	–	–	–	+	+	–
Epididymal pathology/immunopathology	Presence of leucocytic infiltrates	+	nd	nd	+	+	+	nd	nd
	Accumulation of collagen fibres/fibrosis	+	nd	nd	nd	+	+	nd	nd
	Granuloma formation	+	nd	nd	+	+	(+)	–	–
Testicular pathology	Disruption of spermatogenesis/germ cell death	+	+	+	+	+	+	+	+
	Disruption of tight junctions	–	+	nd	+	nd	+	+	+
	Thickened lamina propria of seminiferous tubules	–	+	nd	+	nd	+	+	+
	Accumulation of collagen fibres	nd	nd	nd	+	nd	+	+	+
	Disruption of steroidogenesis	nd	+	+	+	nd	(+)	+	–
Testicular immunopathology	Presence of lymphocytic infiltrates	+	+	–	+	(+)	+	+	+
	Increased number of TH17+ T cells and their cytokines	nd	nd	nd	+	nd	nd	nd	+
	Increased numbers of macrophages/dendritic cells	+	+	+	+	nd	+	+	(+)
	Elevated levels of pro-inflammatory cytokines	+	+	+	+	nd	nd	nd	+
	Formation of immune complexes	nd	nd	nd	+	+	nd	nd	(+)
	HMGB1 release	+	nd	nd	+	nd	nd	nd	+
Systemic immunopathology	Autoantibodies against haploid germ cells	nd	nd	nd	+	+	(+)	–	(+)

LPS, lipopolysaccharide; EAO, experimental autoimmune orchitis; nd, not determined; HMGB1, high mobility group protein B1; TH17, T-helper 17 cells.