Establishment of a reference interval for natural killer cell activity through flow cytometry and its clinical application in the diagnosis of hemophagocytic lymphohistiocytosis

Recently, the Histiocyte Society revised the diagnostic criteria for hemophagocytic lymphohistiocytosis (HLH) to include low or absent natural killer (NK) cell activity, according to local laboratory reference. The aim of this study was to establish reference interval for functional NK-cell activity in 63 healthy Korean individuals using a flow-cytometric assay. We used peripheral blood mononuclear cells (PBMCs) as effector cells and Fluorescein isothiocyanate-labeled K562 cells as target cells. NK-cell activity was calculated using the following equation: NK-cell activity (%) = (test lysis − spontaneous lysis) × 100/(maximum lysis − spontaneous lysis). NK-cell activity was analyzed in 13 known HLH patients and 16 suspected non-HLH patients using a flow-cytometric assay. The mean (±SD) cytotoxicity of PBMCs from healthy individuals was 20.9 ± 5.3% and the reference interval was 11.8–31.9%. The mean NK-cell activity of HLH patients (8.3 ± 8.9%) was significantly lower (P = 0.001) than that of non-HLH patients (20.1 ± 7.8%). The sequential changes in NK-cell activity in the HLH group corresponded to clinical and laboratory findings following treatment. We successfully developed a functional NK-cell activity test for use in the clinical laboratory and obtained a reference interval of NK-cell activity from healthy donors. This assay, and associated reference interval, was used to analyze 30 clinically relevant specimens and the results were shown to be well correlated.     

Rectal guiding tube to facilitate distal colonic stent insertion

Self‐expanding metallic stents for the treatment of acute colonic obstruction is a recent technique showing promising results. Traditionally metallic stents have used a colonoscope as the portal for stent insertion. Our rectal guiding tube has been devised to enable continuous opacification of the colon without contrast or colonic content leakage and provide a rigid portal through which to insert the metallic stent safely. In many situations concomitant use of a colonoscope is not necessary, especially in left‐sided or more distal colonic lesions.     

Ectopic pregnancy: duplex Doppler evaluation

Of 398 patients in whom there was a clinical suspicion of ectopic pregnancy, 96 (24%) were found to have the condition. Of the 96, 70 underwent duplex Doppler imaging. A viable ectopic fetus was seen in 10 of 70 (14%), and an extrauterine sac without an identifiable fetus was seen in an additional 27, giving a sensitivity for imaging alone of 53%. Fetal heart activity was detected with Doppler in 13 (19%). High-velocity flow, which suggested the presence of an ectopic pregnancy, was detected in 38 of 70 (54%) patients (total preoperative sensitivity, 73%). In the 91 patients who did not have an ectopic pregnancy, duplex Doppler imaging of the intrauterine contents alone allowed an ectopic pregnancy to be excluded in 29 (32%) on the first examination and in a further 21 on the second scan (specificity, 55%). Nine vascular adnexal masses were falsely considered to be ectopic pregnancies (specificity, 90%). The positive predictive values were 47% for imaging alone and 85% for Doppler. The negative predictive values were 60% for imaging alone and 81% for Doppler.     

Progressive cardiomyopathic lentiginosis (Leopard syndrome, Moynahan syndrome)

In connection of a sporadic and three familary cases a syndrome involving the skin, heart, eyes, bone-system, hearing organs and genitales is presented. As leading sign of the syndrome, profuse lentigiosis is held to be. Based on this finding, involvement of the other organs may occur too. Specialty of our cases is Marfan-syndrome associated with Leopard syndrome, and blood-vessel anomaly as a new alteration.     

Automated management of screening and diagnostic mammography

We designed an automated system for managing large-scale screening and diagnostic mammography. The system collects coded mammographic findings from the radiologist and records a history directly from the patient. This information is stored in an integrated clinical data base to which the results of subsequent examinations or surgery are added. In addition, the system generates letters to the patient and her physician that describe mammographic findings and letters reminding them of routine screening visits. For patients who have positive results on examinations, it checks for records of biopsy or repeat mammography and generates follow-up letters if appropriate intervention is not found. While this system is part of a comprehensive computerized hospital information system, mammography management tools with most of the features described can be designed for relatively inexpensive microcomputers.