pyrophosphate and Pleural-Effusion

Transthyretin cardiac amyloidosis (ATTR and ATTRv) is an underrecognized cause of heart failure that results from myocardial deposition of misfolded protein (TTR or prealbumin). The diagnosis can be confirmed by uptake of 99m Tc-pyrophosphate ( 99m Tc-PYP) in the heart with serologic studies to rule out light chain disease. We present the case of a 70-year-old woman who underwent a 99m Tc-PYP scan. The patient had a large right-sided pleural effusion that lowered counts in the right chest on planar imaging, interfered with ratio-based grading of PYP uptake, and highlighted the importance of obtaining SPECT/CT for problem-solving in cases where uptake ratios may be spurious.

Topics: Aged; Amyloidosis; Cardiomyopathies; Diphosphates; Female; Humans; Pleural Effusion; Prealbumin; Technetium; Technetium Tc 99m Pyrophosphate

Accumulation of 99m Tc-Sn-pyrophosphate in pleural effusions has been evaluated in 56 patients grouped as follows: 8 with bacterial effusion (Group A), 27 with malignant effusion treated by local and/or parenteral antitumor chemotherapy (Group B), 21 with malignant effusion treated only by supportive therapy (Group C). Results, expressed as effusion to plasma PPi ratio, ranged from 0.1 to 0.28 in group A, from 0.04 to 0.64 in group B and from 0.60 to 1.73 in group C, with significant differences among the three groups. In no case was uptake found in cells of the sediment. Chemical analysis (including total and ionized calcium, total protein, acid and alkaline phosphatase) of plasma and exudate in neoplastic patients showed a slight, but significant, difference between groups B and C as regards plasma-effusion gradient for total calcium and acid phosphatase. Negative correlation also exists between effusion to plasma PPi ratio and plasma-exudate gradient for ionized calcium in neoplastic patients. The data support the hypothesis that acid phosphatase content and calcium gradient are among the factors involved in the mechanism of PPi accumulation in pleural effusions.

Topics: Diphosphates; Humans; Pleural Effusion; Pleural Neoplasms; Radionuclide Imaging; Technetium; Tin

A model is described of acute inflammation in the pleural cavity of rats using calcium pyrophosphate as the irritant. This model would seem to simulate the pseudogout syndrome. It has been shown to be acute in onset, dominated by polymorphonuclear cells, complement independent. The advantage of the model is that volume of exudate, numbers and types of cells may be quantitated. Prostaglandins and cyclic AMP have been measured in the migrating cells. The significance of these findings has been discussed.

Topics: Animals; Calcium Phosphates; Cyclic AMP; Diphosphates; Disease Models, Animal; Indomethacin; Inflammation; Male; Pleural Effusion; Pleurisy; Prostaglandins E; Prostaglandins F; Rats; Snake Venoms