Parvo virus B19 - Pure Red Cell Anemia

Best-documented viral cause of RBC aplasia in

 

• Chronic Hemolysis
• Immunocompromised
• Fetus in utero

Pathology:

Cytotoxic to marrow erythroid progenitor cells by  binding to red cell "P" antigen.

Clinical course:

Normal children: <2wk course. Anemia not present or appreciated.

            Rx: Not required

Hemolytic patient: brief cessation of erythropoiesis may precipitate Aplastic crisis  in already low lifespan RBC.

Most occurs once in life, but should should be isolated from at risk pts.

           Rx: B.T if required.

Recovery in both the cases is spontaneous, with nucleated RBC & reticulocytosis.

Immuno-compromised: severe, no spontaneous recovery, >1 blood transfusion.

          Rx: High dose IVIG.

In-Utero: ↑ 2^nd, 3^rd foetal wastage, hydrops fetalis.

Investigations:

Bone marrow under light m/s:

• decreased erythroid precursors,
• characteristic nuclear inclusions in erythroblasts
• giant pronormoblasts

Lab:

• PCR
• Serum IgM & IgG titers.