A serial section study of tubular confronting cisternae (so-called 'test-tube and ring-shaped forms') in AIDS

A serial section study was executed on a lymph node from a case of AIDS (acquired immune deficiency syndrome) to determine the true three-dimensional morphology and mode of genesis of tubular confronting cisternae which are found in the lymphocytes in this condition. Serial sections from over a hundred such structures show that these are tubular structures and that the 'test-tube and ring-shaped' forms described in the literature are no more than profiles one expects to see when a tubular structure is sectioned. The view at times expressed in the literature that these structures are truly test-tube-shaped (i.e. one end closed) appears to be erroneous, for our serial section study did not reveal a single instance where one end was closed; all were tubular structures with both ends open. We found that tubular confronting cisternae develop by a process of twisting and spiralling of ribbon-shaped confronting cisternae, and that at one stage of development there is a spiralling groove on the wall of this structure. Microtubuloreticular structures were seen in several lymphoid cells, sometimes they were found in cells containing tubular confronting cisternae. At times microtubules (similar to those seen in microtubuloreticular structures) were seen lying within and/or outside the profiles of dense lamina of tubular confronting cisternae.