1375. Laboratory Abnormalities Among Patients with Pulmonary Mycobacterium avium Complex Infections

Abstract

BackgroundLimited data are available regarding laboratory abnormalities in patients with pulmonary Mycobacterium avium complex (MAC) disease.MethodsWe included patients without cystic fibrosis who had pulmonary MAC and met ATS/IDSA disease criteria from the Northwest NTM Biobank with a complete blood count (CBC) 6 months prior and up to 30 days after study enrollment. The biobank is a cohort of patients with Nontuberculous mycobacterium (NTM) infections identified through statewide laboratory surveillance and OHSU regional referral NTM clinic; a complete clinical history is collected by chart review at enrollment. We evaluated the proportion of pulmonary MAC patients with abnormal laboratory tests. We examined differences using a chi-square test between patients who were antimycobacterial treatment naïve, on therapy at enrollment or previously treated, in addition to cavitary and non-cavitary disease and those who also had previous sputum isolation of additional organisms (co-isolation).Results147 patients had CBCs available; 112 (76.2%) were female with a median age of 69 years (22–88 years). 64 (43.5%) were antimycobacterial treatment naïve, 65 (44.2%) were on therapy at enrollment and 18 (12.2%) were previously treated. Lymphocyte count was below normal in 105 (73.4%) patients; 70 (49.3%) had lymphocyte counts below 1500 cells/mL and 27 (18.9%) were lymphopenic. Elevated monocyte percent was seen in 54 (37.2%) patients. Lymphopenia was more common in those on therapy, P = 0.01. There were no predominant laboratory abnormalities in 108 patients with metabolic panels. 34 patients had a c-reactive protein (CRP) collected, which was elevated, after age and gender correction, in 31 patients (91.2%). There was no significant difference between treatment groups. Eleven patients had cavitary disease with no differences in laboratory values compared with those with non-cavitary disease. Patients with co-isolation were more likely to be anemic (P = 0.03), have thrombocytosis (P = 0.04) and were less likely to have a monocytosis (P = 0.03).ConclusionA large proportion of patients with pulmonary MAC disease have low lymphocyte counts, elevated monocyte percent and CRP. Further evaluation of the meaning of these abnormalities as well as changes during therapy is needed. Disclosures All authors: No reported disclosures.