decreased pro-B cell number abnormal pre-pro B cell morphology decreased pre-pro B cell number reduced pre-pro B cell number reduced number of pro-B cells that are CD45R/B220-positive, CD43-positive, HSA-low, BP-1-negative and Ly6c-negative; this cell type is also described as being lin-negative, AA4-positive, Kit-positive, IL7Ra-positive and CD45R-positive csmith 2012-11-16T12:50:14Z MPheno.ontology MP:0011816