Background and Aims

Severe combined immunodeficiency with the presence of B lymphocytes (Nezelof syndrome) is manifested by a pronounced defect of cellular immunity with lymphopenia and thymic dysplasia. This condition is defined as a lymphocytic, normo-plasmocytic and normo-globulinemic aplasia.

Aim: evaluation of morphopathological changes in Nezelof syndrome

Methods

were evaluated data (medical records, morphopathological data, immunohistochemical staining) of 36 patients aged 0-18 years diagnosed at the Institute of Mother and Child from Moldova with primary immunodeficiency postmortem to detect any Nezelof syndrome.

Results

Nezelof syndrome was detected in 4 patients (11.1%). It is characterized by thymic hypoplasia and dysplastic changes defined by the presence of concentrically arranged epithelial cells and the total lack of Hassall corpuscles and its predecessors. There was also no corticomedullary segregation. Thymic parenchyma was composed only of a reticular stroma with total lymphocyte depletion (fig.1). Also, in the spleen and the lymph nodes, besides lymphocyte depletion, there were numerous plasmocites. The same changes were observed in the intestinal lymphoid follicles, especially the presence of plasmocites.

Conclusions

Thymic hypoplasia and dysplastic changes, manifested by the presence of pseudoglandular structures of the reticulo-epithelium, lack of Hassall corpuscles, and depletion of lymphocyte from the lymphoid tissue are morpfopatological data about Nezelof syndrome.