Do measles early giant cells result from fusion of non-infected cells? An immunohistochemical and in situ hybridization study in a case of morbillous appendicitis

Abstract

A case of acute appendicitis with features of measles inflammatory reaction is studied. Two types of lymphoid polykaryons are seen: Warthin Finkeldey cells inside germinal centres (LN1 ++, LN2 +, L26 +, MB1 +, MB2 +/-) and multinucleate plasma cells in the lamina propria (mu +, alpha ++, kappa +, lambda +). Both types of polykaryon are devoid of inclusions. The search for viral genetic information by in situ hybridization was negative in these cells. A positive signal was observed in interfollicular mononuclear cells and rare enterocytes. A possible mechanism of fusion from without, acting at the beginning of the disease to induce the appearance of polykaryons, is discussed.

Macrophages and Dendritic Cells Are the Predominant Cells Infected in Measles in Humans

“…However, in general, although the presence of MV proteins and/or genome in tissues was demonstrated in these studies, only classical staining techniques were used to assess the identity of infected host cells. Those few studies of MV pathogenesis in which human-cell-specific markers and protein markers were used have been restricted to lymphocyte and cytokine identification ( 48 – 52 ).…”

Histopathologic characteristics of the transitional stage of measles-associated appendicitis: case report and review of the literature

“…As yet, 25 cases of measles-associated acute appendicitis have been documented in the English literature (Table 2) [3][4][5][6][7][8][9][10][11][12][13]. Complete clinicopathologic data could not be determined from the pathology reports from all patients because of missing data or lack of histopathologic examination of resected appendiceal specimens.…”

“…Gaulier et al [11] speculated that lysis of infected cells results in the release of virions containing F surface protein that may induce B-cell fusion. The cytoplasmic CD68 expression of WFC in our case may be evidence for an additional differentiation toward T zone-associated plasmacytoid monocytes [15].…”

“…Previous studies indicate that WFCs are a result of cell fusion during the early phase of measles infection. The typical WFCs are located in the germinal centers of lymphoid follicules and stain with CD20 and CD79a, corresponding to a centrofollicular B-cell lineage [11,[13][14]. Interfollicular WFC cells appear later and stain with intracytoplasmic immunoglobulins, corresponding to a plasmacytic phenotype [11].…”

Follicular necrotic keratinocytes – a helpful clue to the diagnosis of measles

“…Syncytial‐type multinucleated giant cells (typically in measles infection called Warthin–Finkeldey cells) have been described in inflammatory reactions of other tissues (such as lymphoid and lung tissue) in patients with measles infection . They have also been reported in other viral infections, such as HSV I and II, HIV, parainfluenza type 2 and type 3 and respiratory syncytial viruses .…”