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BackgroundViral infections are pervasive and leading causes of myocarditis. Immune-suppression after chemotherapy increases opportunistic infections, but the incidence of virus-induced myocarditis is unknown.ObjectiveAn unbiased, blinded screening for RNA viruses was performed after chemotherapy with correlation to cardiac function.MethodsHigh-throughput sequencing of RNA isolated from blood samples was analyzed following chemotherapy for hematological malignancies (N = 28) and compared with left ventricular ejection fraction (LVEF).ResultsOn initial rigorous analysis, low levels of influenza orthomyxovirus and avian paramyxovirus sequences were detectable, but without significant correlation to LVEF (r = 0.208). A secondary broad data mining analysis for virus sequences, without filtering human sequences, detected significant correlations for paramyxovirus with LVEF after chemotherapy (r = 0.592, P < 0.0096). Correlations were similar for LVEF pre- and post- chemotherapy for orthomyxovirus (R = 0.483, P < 0.0421). Retrovirus detection also correlated with LVEF post (r = 0.453, p < 0.0591), but not pre-chemotherapy, but is suspect due to potential host contamination. Detectable phage and anellovirus had no correlation. Combined sequence reads (all viruses) demonstrated significant correlation (r = 0.621, P < 0.0078). Reduced LVEF was not associated with chemotherapy (P = NS).ConclusionsThis is the first report of RNA virus screening in circulating blood and association with changes in cardiac function among patients post chemotherapy, using unbiased, blinded, high-throughput sequencing. Influenza orthomyxovirus, avian paramyxovirus and retrovirus sequences were detectable in patients with reduced LVEF. Further analysis for RNA virus infections in patients with cardiomyopathy after chemotherapy is warranted.

Introduction: Chemotherapy for hematologic malignancies can cause severe cardiomyopathy. Chemotherapeutic agents also induce immune suppression increasing the risk of opportunistic infections. Hypothesis: We have hypothesized that immunosuppression after chemotherapy increases opportunistic viral infections, myocarditis and cardiomyopathy. Methods: Viral gene sequences were identified using an unbiased high-throughput sequencing approach of patient blood samples following chemotherapy treatment for hematological malignancies (N = 28). Detected viral sequences were correlated with cardiac ejection fraction (LVEF) measured before and after treatment. Results: In a blinded analysis undertaken by two investigators viral sequences were identified in blood samples from patients after chemotherapy. Low levels of Influenza A, orthomyxovirus and Avian Paramyxovirus sequences were detected but identified individual virus sequences did not have a significant correlation to reduced LVEF post chemotherapy (r = 0.177-0.293). Detected sequences for all RNA viruses combined did indicate some correlation with LVEF, r = 0.621, suggesting potential for nonspecific RNA virus detection ( p < 0.0078). In a secondary broad screen, data mining was performed including all detectable viral sequences without the filtering of human related sequences. In this broad analysis a significant correlation was detected for Paramyxovirus with reduced cardiac LVEF (r = 0.592 post, compared to r = 0.464 prior to chemotherapy; P < .0096). For detected Orthomyxovirus sequences correlations were similar for LVEF pre- and post- chemotherapy (R = 0.483, P < 0.0451). Retroviruses reads were increased but suspect due to human genome retrovirus sequences (R= 0.512; P < 0.0351). No correlation was seen for Anellovirus, a DNA virus. Reduced LVEF did not correlate with chemotherapy (p = NS). Conclusions: This is the first report of screening for RNA viruses in the circulating blood of patients post chemotherapy using a high-throughput sequencing approach. Influenza Orthomyxovirus and Avian Paramyxovirus sequences were detectable in patients with reduced LVEF after chemotherapy. Further analysis for RNA virus infections in cardiomyopathy after chemotherapy is warranted.