The use of aldosterone-renin ratio as a diagnostic test for primary hyperaldosteronism and its test characteristics under different conditions of blood sampling

Recent reviews recommended the use of the aldosterone/renin ratio (ARR) to screen for primary hyperaldosteronism. However, widely different cutoff levels have been proposed, and test characteristics of ARR under different conditions of sampling are not known. We conducted a retrospective review among 45 subjects with carefully validated diagnoses of primary hyperaldosteronism and 17 subjects with essential hypertension to study the utility of ARR. Sixty-two patients with 75 sets of plasma renin activity (PRA), aldosterone, and ARR values from a postural study and 48 sets of values from a saline suppression test were analyzed. Ninety-four percent of these subjects underwent investigations because of hypokalemic hypertension.ARR yielded larger areas under the curve in the receiver-operating-characteristics curve than PRA or aldosterone under all conditions of testing. Our results confirmed the superiority of ARR to either aldosterone or PRA alone as a diagnostic test for primary hyperaldosteronism.ARR cutoff levels were significantly affected by the condition of testing. Depending on posture and time of day, it varied from 13.1-35.0 ng/dl per ng/ml.h in our study population. When using ARR for screening primary hyperaldosteronism, posture and time of sampling should be standardized both within and between centers to minimize variability in cutoff levels.     

Sarcomatous transformation in diaphyseal aclasis

Multiple hereditary exostosis (or diaphyseal aclasis) is a condition characterized by the development of multiple osteochondromas. The tendency for malignant transformation into chondrosarcoma is well known. Malignancy typically arises from the cartilaginous cap of the osteochondroma. Radiographs supplemented by computed tomography have an important role in the diagnosis of this condition. Magnetic resonance imaging shows the features of sarcomatous change and aids in differentiating malignancy from pseudotumours.     

Solid tumors subsequent to arsenic trioxide treatment for acute promyelocytic leukemia

Arsenic trioxide (As(2)O(3)) is highly efficacious for acute promyelocytic leukemia (APL). Environmental arsenic exposure predisposes to malignancies, but the risk for therapeutic arsenic is undefined. Three APL patients (de novo, 2; therapy-related, 1) in a cohort of 59 cases given oral-As(2)O(3) for induction and maintenance treatment developed secondary cancers (nasopharyngeal carcinoma, 2; colonic adenocarcinoma, 1) at 16, 36 and 55 months post-As(2)O(3) therapy. Retrospective analysis of biomarkers (Epstein Barr virus serology and quantification, carcinoembryonic antigen) showed the potential presence of cancers before or shortly after As(2)O(3) therapy, suggesting that As(2)O(3) had not initiated these malignancies. Compared against matched background population, there was an increased risk of second cancer (p=0.012, standard incidence ratio=6.5; 95% confidence interval=1.4-19.0).     

Early onset wheeze associated with enhanced combined IL‐1β, IL‐6, and IL‐12/IL‐23p40 in LPS‐stimulated cord blood mononuclear cells

Background Neonates with a family history of atopy are at higher risk for developing wheezing in early life. Objective From a birth cohort of at risk infants (first‐degree family with atopic disease), we evaluated the influence of distinct intrinsic immunologic risk factors on wheezing disorders in the first 2 years of life. Methods Cord blood samples were collected from 195 eligible subjects of a birth cohort of 253 subjects. The subjects studied were those who developed wheezing (n=34) or eczema (n=29) in the first 2 years of life, and 65 healthy control infants. At the time of thawing the viability of the cells were median 70% (range 67.5%–72.5%). Cytokines from lipopolysaccharide (LPS)‐stimulated mononuclear cells were analysed using fluorescent‐activated cell sorting‐array and their profiles were evaluated using factor analysis. Results Infants with wheeze were significantly associated with enhanced combined LPS stimulated IL‐1β, IL‐6, and IL‐12/IL‐23p40 compared with healthy controls (P=0.003). This profile was also associated with the increased risk for wheeze at 2 years of age (OR=2.45; 95% CI=1.50–3.93, P=0.001). LPS‐stimulated cytokine IL‐8 was also significantly higher in the wheeze group compared with healthy controls and eczema (P=0.003). Intracellular staining showed that monocytes are main producers of IL‐6 and IL‐8 from cord blood mononuclear cells. Most of the subjects were non‐atopic with 3/34 (9%) wheeze and 9/29 (31%) eczema subjects sensitized to the common dietary or inhalant allergens. Conclusion and Clinical Relevance In infants at genetic risk of atopy, wheeze but not eczema in the first 2 years of life is associated with intrinsic hyperresponsive innate cytokine responses which might predispose infants to wheeze development. Distinct pre‐symptomatic hyperresponsive innate immune responses risk factors were found to be associated with early onset wheeze disorders, but not eczema. Cite this as: P. L. Quah, I‐C Kuo, C. H. Huang, L. P‐C Shek, B. W. Lee and K. Y. Chua, Clinical & Experimental Allergy, 2011 (41) 970–978.     

Platelet turnover and kinetics in immune thrombocytopenic purpura: results with autologous 111In-labeled platelets and homologous 51Cr- labeled platelets differ

Mean platelet survival and turnover were simultaneously determined with autologous 111In-labeled platelets (111In-AP) and homologous 51Cr- labeled platelets (51Cr-HP) in ten patients with chronic immune thrombocytopenic purpura (ITP). In vivo redistribution of the 111In-AP was quantitated with a scintillation camera and computer-assisted image analysis. The patients were divided into two groups: those with splenic platelet sequestration (spleen-liver 111In activity ratio greater than 1.4), and those with diffuse sequestration in the reticuloendothelial system. The latter patients had more severe ITP reflected by pronounced thrombocytopenia, decreased platelet turnover, and prominent early hepatic platelet sequestration. Mean platelet life span estimated with 51Cr-HP was consistently shorter than that of 111In-AP. Platelet turnover determined with 51Cr-HP was thus over-estimated. The difference in results with the two isotope labels was apparently due to greater in vivo elution of 51Cr. Although the limitations of the techniques should be taken into account, these findings indicate that platelet turnover is not always normal or increased in ITP, but is low in severe disease. We suggest that this may be ascribed to damage to megakaryocytes by antiplatelet antibody. The physical characteristics in 111In clearly make this radionuclide superior to 51Cr for the study of platelet kinetics in ITP.     

Determination of the solute removal index for urea by using a partial spent dialysate collection method

In 22 hemodialysis patients, during a dialysis session, the solute removal index (SRI) for urea obtained from the use of a partial spent dialysate collection method was compared with that derived from the use of a total spent dialysate collection technique. The partial spent dialysate collection method was used to harvest a small representative sample of the total spent dialysate. The volumes of spent dialysate collected by the partial and the total spent dialysate collection methods were 1.7 +/- 0.4 L and 129.6 +/- 15.3 L, respectively. The total amount of urea nitrogen removed by dialysis as estimated by the partial spent dialysate collection method was similar to that determined by the total spent dialysate collection approach. As a result, the SRI value for urea obtained by the partial spent dialysate collection method (namely, 63% +/- 8%) correlated very well (r = 0.95, P < 0.001) with that derived by the total spent dialysate collection technique (namely, 62% +/- 8%). Our data suggest that it is feasible to use a simple partial spent dialysate collection method to obtain SRI results in patients treated with hemodialysis.     

Transcranial magnetic stimulation in patients with bipolar depression: a double blind, controlled study

Dolberg OT, Dannon PN, Schreiber S, Grunhaus L. Transcranial magnetic stimulation in patients with bipolar depression: a double blind, controlled study. Bipolar Disord 2002: 4(Suppl. 1): 94–95. © Blackwell Munksgaard, 2002