TESTICULAR MACROPHAGES IN PATIENTS WITH NON-OBSTRUCTIVE AZOOSPERMIA

V.MUŽIĆ(1), D.JEŽEK(1), LJ. BANEK(1), F. BULIĆ-JAKUŠ(2), R. PEZEROVIĆ-PANIJAN(1), G. JURIĆ-LEKIĆ(1)

1Dept. of Histology and Embryology; 2Dept. of Biology, Medical School University of Zagreb, Croatia

INTRODUCTION

Within the testicular interstitial compartment there is a number of immunocompetent cells like macrophages, neutrophil leukocytes, monocytes, eosinophils and lymphocytes (1,2). Among them, macrophage population is the largest one and is supposed to influence the function of the neighbouring Leydig cells and the production of testosterone (1,3). In the normal human testis, macrophages are encountered in the testis interstitium. None of these cells are present within the seminiferous tubules (4).

AIM

The present study deals with the testicular macrophages in infertile men suffered from the non-obstructive azoospermia. Using immunohistochemistry (IHC) and transmission electron microscopy (TEM) we wanted to compare controls (testicular biopsies with normal testicular morphology) and infertile group (biopsies from infertile patients) and to check if there were any differences in the macrophage population between the two groups.

MATERIALS & METHODS

In total, 60 testicular biopsies from infertile men (aged 28-39 y.) were analysed. All infertile patients contacted an andrologist because of the male-factor infertility. 8 biopsies from men with vasectomy reversal (aged 34-45 y.) served as controls. IHC analysis was performed using primary antibody to KiM1P1 molecule, identified within the cell membrane of human macrophages. KiM1P1 proved to be a reliable and specific marker of these cells. TEM analysis was done using Carl Zeiss 902A transmission microscope.

RESULTS

In control biopsies, a moderate presence of macrophages was found within the testis interstitial tissue (Fig.1). Some cells were found attached to blood vessels, and a number of them were localised in the close vicinity of seminiferous tubules. There was no presence of macrophages within the seminiferous epithelium, i.e. inside the tubules. In infertile group, an increased number of macrophages could be found. There was a significant number of these cells within the interstitial compartment (Fig.2). Moreover, some macrophages were found within the lumen of seminiferous tubules (Fig.2). TEM analysis demonstrated a significant difference in ultrastructure between controls and infertile specimens. Macrophages of infertile men had more indentations of the nucleus, an increased presence of primary, secondary lysosomes as well as phagolysosomes, well-developed Golgi apparatus and numerous cisternae of rough endoplasmic reticulum (RER). All this ultrastructural properties indicated activation of these cells.

CONCLUSION

There was a significant rise in number of macrophages in biopsies of infertile men suffering from the non-obstructive azoospermia. Some of the macrophages were identified within seminiferous tubules. At the ultrastructural level, these cells had more lysosomes, abundant Golgi apparatus and RER which indicated their activation and increased phagocytic activity. The increased presence of macrophages and their activation could lead to sperm loss in patients with non-obstructive azoospermia.

Fig. 1.Fig. 2.

Fig. 3. Fig.4.

Figs 1. and 2. Testicular macrophages identified by KiM1P1 immunohistochemistry. Note the significant difference in the presence of these cells between control (Fig. 1) and infertile group of patients (Fig.2). Some cells are indicated by arrows (stars = seminiferous tubules, x400, scale = 50µm).

Fig. 3. Two macrophages (arrows) in the close vicinity of the seminiferous tubule (stars = myoid cells; x3000, scale = 10 µ).

Fig. 4. One of the macrophages depicted in Fig. 3. Note the indented nucleus (arrow), and the cytoplasm rich in lysosomes and RER (x7000, scale = 5µm)

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