The distribution of iron and iron binding proteins in spleen with reference to Hodgkin's disease.

The distribution of iron and iron binding proteins (IBP) have been compared with control spleen tissue in an attempt to establish a pattern of staining restricted to Hodgkin's disease (HD). All but one of the HD spleens examined stained for ferritin, which was largely present in red pulp dendritic macrophages (DM). In spleens histologically involved with HD heavy deposits of ferritin were seen around tumour nodules. Staining for ferritin increased with involvement of the spleen in HD but DM still represented the bulk of positive cells. However, ferritin positive DM were frequently seen in control spleens, and often in large numbers. Staining of ferric iron by Perls technique was less prominent than ferritin but this observation was also true of the non-HD spleens studied. Patterns of staining with transferrin were equivalent in both groups of spleens with DM being the most frequently positive cell type. Polymorphous macrophages showing erythrophagocytosis were present in the red pulp sinuses of all groups of spleens and although these cells have been considered as precursors of the Reed-Sternberg cell their presence seemed related to total splenic ferritin regardless of the disease process. These cells marked as macrophages and their presence was not restricted to HD. The results show that there is no particular appearance of iron or IBP distribution which is restricted to HD spleens. However, staining for ferritin and iron increased in HD spleens with tumour involvement and could contribute to circulatory abnormalities in this disease.

Tissue preparation for the demonstration of surface antigen by immunoperoxidase techniques.

The fixation and drying regimes for frozen sections and cytocentrifuge preparations for the demonstration of surface antigens, such as immunoglobulins and iron binding proteins, vary enormously between different groups of workers. A method using freeze-dried sections and acetone fixation was compared with 16 other methods of fixation and found to be the best for tissue preservation and antigen demonstration. Freeze drying was found to improve the cytological preservation of air-dried sections considerably.