A rare combination of thrombotic thrombocytopenic purpura and antiphospholipid syndrome

: Thrombocytopenia, in the setting of microangiopathic hemolytic anemia and thrombotic events, is characteristic of both thrombotic thrombocytopenic purpura and primary antiphospholipid syndrome. Clinically, it is difficult to distinguish between these two syndromes. We present a 41-year-old woman with chronic, relapsing thrombotic thrombocytopenic purpura in the presence of antiphospholipid antibodies. She had clinical manifestations of antiphospholipid syndrome without meeting laboratory criteria of the Sydney classification system. In the literature, there have only been nine cases of thrombotic thrombocytopenic purpura associated with primary antiphospholipid syndrome. Seven of the nine cases suffered from one or multiple strokes, a common feature in antiphospholipid syndrome, but an uncommon finding in thrombotic thrombocytopenic purpura. We introduce the possibility of an association between thrombotic thrombocytopenic purpura and the presence of antiphospholipid antibodies. Systematic testing of ADAMTS13 activity and anti-ADAMTS13 antibodies in patients who present with neurological symptoms and thrombocytopenia, in the presence of antiphospholipid antibodies, may help with the diagnosis of the rare thrombotic thrombocytopenic purpura-antiphospholipid syndrome combination.

Chemical and thyroid hormone profile of the bone marrow interstitial fluid in hematologic disorders and patients without primary hematologic disorders

Bone marrow interstitial fluid (BMIF) has not been well characterized. BMIF was isolated from 60 patients including plasma cell dyscrasias (PCD, n = 33), other primary hematologic disorders (OHD, n = 15), and patients with secondary or nonhemtologic disorders (NHD, n = 12) and analyzed for an array of chemical constituents. These included total cholesterol, glucose, phosphate, creatinine, urea, total protein, albumin, globulins, total bilirubin, aspartate aminotransferase, lactate dehydrogenase, sodium, osmolarity, free triiodothyronine (free T3), total triiodothyronine (total T3), and free tetraiodothyronine (free T4). Levels of BMIF components were compared between patient groups and to plasma levels. Compared with plasma, total cholesterol, total protein, total bilirubin, sodium, and calculated osmolarity were lower in BMIF in all groups (P < 0.05). Calculated globulins and aspartate aminotransferase were lower in BMIF of PCD patients and patients with NHD. Albumin was lower in BMIF of patients with PCD and patients with OHD. Lastly, free T4 was significantly higher in BMIF of patients with PCD and patients with OHD. Similar results were demonstrated in a separate analysis performed in patients with multiple myeloma. To conclude, the chemical and thyroid hormone composition of BMIF differs significantly from plasma in several key constituents.

Liver SULmean at FDG PET/CT: interreader agreement and impact of placement of volume of interest

PURPOSE

To evaluate how interreader agreement and the site of the volume of interest (VOI) affect the agreement and variability of liver mean standardized uptake value normalized to lean body mass (SUL(mean)) at fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT).

MATERIALS AND METHODS

Institutional review board approval was obtained for this HIPAA-compliant retrospective review of PET/CT images and patient records. PET/CT images were reviewed in 116 randomly selected patients who had undergone a baseline PET/CT examination and who had normal livers according to imaging and biochemical test results. A 30-mm-diameter spherical VOI was placed within the right lobe of the liver above, below, and at the level of the main portal vein. Two readers performed all measurements independently. Analysis of variance, intraclass correlation coefficient (ICC) analysis, and Bland-Altman analysis were performed.

RESULTS

The mean SUL(mean) was between 2.11 and 2.17 at the upper, portal, and lower levels of the right lobe of the liver. The coefficient of variance was between 21.0% and 23.1%, without significant differences for location, with the least variance in the upper level. The ICC of the two readers varied between 0.98 and 0.99 (95% confidence interval [CI]: 0.97, 0.99; P = .0001) at each level. The greatest precision (narrowest CI) was also in the upper level. Bias was 0.025 ± 0.10 (standard deviation) at the upper level, was 0.004 ± 0.14 at the lower level, and was 0.047 ± 0.10 at the portal vein (P = .02). For each reader, there was almost perfect reliability between the SUL(mean) measurements made at the three levels, with an ICC of 0.98 (95% CI: 0.98, 0.99; P = .0001).

CONCLUSION

Liver SUL(mean) at FDG PET/CT has excellent interreader agreement, with similar values and variance whether measured at the upper, lower, or portal vein levels within the right lobe of the liver.

PET/CT mediastinal and liver FDG uptake: effects of biological and procedural factors

INTRODUCTION

To establish the effects of biological and procedural factors on mediastinal and liver [(18) F]-fluorodeoxyglucose (FDG) uptake in oncological FDG positron emission tomography/computed tomography (PET/CT).

METHODS

This retrospective study included 557 patients who had a baseline FDG PET/CT scan in 2008 and 2009. Mediastinal and liver standardised uptake values mean normalised to lean body mass (SUVlbm mean) were measured in each patient. Univariate and multivariate regression models were established. Study population was then dichotomised into low and high body mass index (BMI) groups, and linear regression models were established for the effects of age, incubation period and blood glucose levels.

RESULTS

BMI had the highest adjusted effect (standardised beta coefficient, b = 0.43) (P < 0.001) and partial correlation, adjusting for covariates included in the final model (r = 0.45; P < 0.001) on mediastinal FDG uptake. Partial correlations (r) were 0.22 for age, -0.17 for male gender, -0.25 for incubation period and 0.14 for blood glucose (P < 0.001). The linear regression models showed significant differences in mediastinal FDG uptake between the low and high BMI groups and the effects of age, incubation period and basal blood glucose levels (P < 0.001). Similar results were observed for liver FDG uptake except the partial correlation for incubation period was r = -0.09 (P = 0.02).

CONCLUSION

BMI has the highest effect and correlation on mediastinal and liver FDG uptake. FDG uptake time has a greater effect on mediastinal than liver SUVlbm mean.