Increased serum pro-B-type natriuretic peptide in hematopoietic progenitor cell donors stimulated with G-CSF.

Hematopoietic stem cells (HPCs) donors mobilized by granulocyte-colony-stimulating factor (G-CSF) can develop various signs and symptoms. proBNP (pro-B-type natriuretic peptide) is a serum marker of heart failure. A donor who developed severe adverse reactions after G-CSF mobilization was found to have high serum proBNP levels. We followed additional donors who received identical mobilization regimen to investigate the prevalence of this phenomenon. Eighteen healthy donors underwent a mobilization regimen of 10 µg/Kg G-CSF daily for 5 days prior to allogeneic HPC collection using Spectra Optia between January 2016 and February 2017 were included in this study. Serum proBNP levels were measured before and after G-CSF stimulation and immediately after apheresis. Apheresis collection parameters and other laboratory results were also reviewed. The majority of donors (86.7%) had post-G-CSF elevation of serum proBNP. Seven of those had elevated proBNP above upper normal range (124 pg/ml). The subgroup of donors with normal proBNP is younger (median age of 37 vs 42 years), with majority being male (90.9% vs 28.6%) and with smaller processed blood volume (2.2 vs 3 × total blood volume). This case series demonstrates an increase of serum proBNP can be common in HPC donors stimulated with 5 days of 10 mcg/kg G-CSF. This is an adverse reaction that has not been described before. The temporary elevation of proBNP in these donors is not associated with ventricular dysfunction of the heart. The risk factors for marked elevation of proBNP post-G-CSF should be further investigated.

The clinical relevance of persistent recombinant immunoblot assay-indeterminate reactions: insights into the natural history of hepatitis C virus infection and implications for donor counseling.

BACKGROUND: Recombinant immunoblot assay (RIBA) is used to determine the specificity of antibody to hepatitis C virus (anti-HCV). The RIBA result is recorded as positive, negative, or indeterminate. The interpretation and significance of RIBA-indeterminate reactions are unclear. We addressed the clinical relevance of these reactions in the context of the natural history of HCV infection in a prospectively followed cohort of anti-HCV-positive blood donors. STUDY DESIGN AND METHODS: Donor demographics, exposure history, and humoral and cell-mediated immunity (CMI) were compared in 15 RIBA-indeterminate subjects, nine chronic HCV carriers, and eight spontaneously recovered subjects. Serum samples were tested for anti-HCV by a quantitative, liquid luciferase immunoprecipitation system (LIPS). CMI was assessed by interferon-γ enzyme-linked immunosorbent spot assay. RESULTS: In the LIPS assay, the sum of antibody responses to six HCV antigens showed significant (p < 0.001) stepwise diminution progressing from chronic carriers to spontaneously recovered to RIBA-indeterminate subjects. CMI responses in RIBA-indeterminate subjects were similar to spontaneously recovered subjects and greater than chronic carriers and controls (p < 0.008). A parenteral risk factor was identified in only 13% of RIBA-indeterminate subjects compared to 89% of chronic carriers and 87% of spontaneously recovered subjects. RIBA-indeterminate donors were older than the other groups. CONCLUSION: The CMI and LIPS results suggest that persistent RIBA-indeterminate reactions represent waning anti-HCV responses in persons who have recovered from a remote HCV infection. In such cases, detectable antibody may ultimately disappear leaving no residual serologic evidence of prior HCV infection, as reported in a minority of long-term HCV-recovered subjects.