Novel cytomorphology of the giant proerythroblasts of parvovirus B19 infection

Abstract

The morphology of the giant proerythroblasts (GPE) in air-dried and Wright-Giemsa-stained smears of bone marrow in 16 patients with pure red cell aplasia (PRCA) caused by parvovirus B19 infection is described. B19 infection was diagnosed by the presence of the virus or viral DNA and/or IgM antibodies. Twelve patients had chronic hemolytic anemia and aplastic crisis and 4 patients had AIDS with chronic PRCA. In patients with chronic hemolytic anemia and aplastic crisis, GPE were not detectable in bone marrow biopsies that showed any degree of recovery of erythropoiesis. The GPE morphology was quite variable. The early (basophilic) GPE measured 25 to 35 microm in diameter, had a narrow rim of intensely blue and often vacuolated cytoplasm with pseudopodia, round nuclei with compact uncondensed chromatin, and an indistinct and inclusion-like purple-colored tinctorial change. The "intermediate" and "late" GPE measured 25 to 45 microm in diameter and showed cytoplasmic swelling, gradual loss of cytoplasmic basophilia, and fraying of the cytoplasm with focal rupture; the nuclei showed an increase in volume, a highly uncondensed and coarse sieve-like chromatin, and 1 to 3 prominent, pale to moderate purple inclusion-like nucleoli or inclusions. Bare nuclei similar in size and chromatin pattern to those of the GPE were present in proximity to the GPE and may have arisen from the GPE by dissolution of the cytoplasm. The glassy intranuclear inclusions with central clearing, the so-called lantern cells described in formalin-fixed tissues of patients with B19 infection, were absent in all cases. These findings suggest that direct toxic cell injury rather than apoptosis may be involved in the pathogenesis of erythroid aplasia in B19 infection.

A review of blood diseases and cytopenias associated with human parvovirus B19 infection

“…The classic bone marrow sign of pure red cell aplasia caused by B19 infection is the giant pronormoblast (GPNB) or giant proerythroblast . In this study, GPNB were not detectable in any patient with chronic hemolytic anemia and aplastic crisis, who showed any sign of recovery of erythropoiesis . The morphology of GPNB was quite variable.…”

Parvovirus B19 Infection in Hashimoto's Thyroiditis, Papillary Thyroid Carcinoma, and Anaplastic Thyroid Carcinoma

“…The increased presence of B19 capsid could be a result of more efficient B19 infection in these tumors, or of B19 replication, an important area of future investigation. Figure 4B and C demonstrates nuclear features of these B19 capsid protein-positive cells from aggressive thyroid tumors that resemble the enlarged nuclei seen in giant proerythroblasts, cells known to support B19 replication (32). Detection of B19 in these enlarged bone marrow cells has also been correlated with p53 expression (23), a common mutation in ATC tumors.…”

Human Parvovirus B19: An Infectious Agent with the Potential to Induce and Trigger Rheumatic Disease

“…The pathogenesis begins with acquisition of virus usually via the respiratory tract, following which replication presumedly occurs in the nasopharyngeal lymphoid tissue leading to viremia with subsequent infection and destruction of erythroblasts in the bone marrow [6]. Various studies document a direct pathogenic or 'lytic' effect on erythroid cell precursors [226,227], and the giant pronormoblast (25-32 m diameter), also referred to as the lantern cell, is characteristic, but not invariable in B19-infection (Fig. 7) [228,229].…”