Gastroesophageal Reflux and Microaspiration in Lung Transplant Recipients: The Utility of a Single Esophageal Manometry and pH Probe Monitoring Study.

BACKGROUND: Gastroesophageal reflux (GER) in recipients of lung transplant (LTX) is associated with chronic allograft rejection, presumably via microaspiration that damages airway epithelium. Most LTX programs perform a single post-LTX esophageal study to evaluate for GER; the efficacy of this test is unclear. METHODS: Patients with 1 year of post-LTX follow-up, including routine bronchoscopies with bronchoalveolar lavage fluid (BALF) samples as well as high-resolution esophageal manometry and pH probe monitoring (HREMpH), were evaluated. BALF samples were analyzed with competitive enzyme-linked immunosorbent assay to detect bile salts, which are indicative of aspiration. These results were compared to results of HREMpH studies post LTX. RESULTS: Ninety BALF samples were analyzed for bile salts and acted as disease positive for this evaluation. Of the 13 HREMpH cases, 8 were positive for GER, but only 3 were positive for bile salts via assay. Of the 5 HREMpH-negative cases, 2 experienced aspiration. A solitary HREMpH study had 60.0% sensitivity and 37.5% specificity with positive and negative likelihood ratios: 0.96 and 1.07, respectively. CONCLUSION: Microaspiration appears to be an intermittent phenomenon, and HREMpH screening poorly correlates with BALF evidence of aspiration; which may not be adequate. As aspiration detection is crucial in this population, further analysis is warranted.

Quantification of isoforms of plasma MM creatine kinase (CK) with an immunoblot procedure.

The MM isoenzyme of creatine kinase, a dimer composed of two M ("muscle type") subunits, is found in myocardium, where it constitutes 85% of tissue CK, and in skeletal muscle, where it constitutes virtually 100%, as well as in other tissues. The tissue form is designated MMA. When MMA circulates in plasma, it undergoes stepwise, post-translational modification, mediated by proteolytic enzymes in plasma and giving rise to isoforms called MMB and MMC, which lack carboxy terminal lysine on one or two subunits, respectively. We have shown previously that changes with time in plasma profiles of MM creatine kinase (CK) isoforms in dogs reflect myocardial infarction within 1 hour after the onset of coronary occlusion and permit noninvasive detection of reperfusion within 30 minutes after release of an occlusive coronary arterial ligature. However, analysis of MM CK isoforms in plasma from patients has been hampered by the lack of availability of quantitative as opposed to qualitative methods. This study was performed to develop and validate an assay with the sensitivity and specificity needed for accurate quantification of MM CK isoforms in samples of plasma from patients. A rapid assay procedure will be required ultimately for prospective, clinical use. However, as a first step and for use in development and standardization of rapid assays, a procedure is needed for accurate qualification of isoforms even if its implementation is laborious and slow. The isoform composition of normal plasma was found to comprise 32.0% MMA, 34.9% MMB, and 32.7% MMC.(ABSTRACT TRUNCATED AT 250 WORDS)