sodium-pertechnetate-tc-99m and Anemia--Sickle-Cell

Asplenic patients are at risk for pneumococcal sepsis. Patients with hyposplenic function, such as associated with sickle cell disease (SCD), are also at risk. However, tests to assess splenic function are either unavailable or lacking standardization. The aim of this study was to compare different methods for determining splenic function. Eighteen patients with SCD (i.e., 10 heterozygous (SC) and 8 homozygous (SS) SCD patients), and eight splenectomized patients were compared to 10 controls. All subjects underwent spleen scintigraphy, after which functional splenic volumes (FSV) were calculated. FSV was compared to immunological function and B cell-subsets, as well as phagocytic function represented by the presence of Howell Jolly bodies (HJB) and percentages of pitted red cells (PIT). Heterozygous SCD (SC) patients had increased splenic volumes, but diminished FSV, homozygous SCD (SS) patients were asplenic. Splenectomized and SS patients had a strongly reduced phagocytic and immunological function. SC patients had reduced anti-polysaccharide responses without an increase in PIT. FSV correlated significantly with phagocytic and immunological function. HJB were indicative of splenic dysfunction, HJB absence was not indicative of normal functioning splenic tissue. Although visualizing HJB is methodologically advantageous to PIT, both are valid biomarkers of splenic dysfunction. The amount of non-switched memory B cells is strongly correlated to FSV.

Topics: Adult; Aged; Anemia, Sickle Cell; Antibody Formation; Antigens; Erythrocyte Inclusions; Erythrocytes; Erythrocytes, Abnormal; Female; Humans; Immunologic Memory; Lymphocyte Subsets; Male; Middle Aged; Organ Size; Phagocytosis; Radionuclide Imaging; Sickle Cell Trait; Sodium Pertechnetate Tc 99m; Spleen; Splenectomy; Splenic Diseases; Vaccination; Young Adult

The preferential accumulation of sickle blood cells in tumor vasculature is demonstrated noninvasively using MRI and sickle red blood cells loaded with Gd-DTPA and invasively by two other techniques. The distribution of red blood cells in rat brain tumors relative to normal brains were measured using three separate techniques: MRI of Gd-DTPA loaded cells, fluorescent microscopy detection of Oregon Green 488 fluorescence conjugated to a streptavidin-biotin complex that binds to red blood cell surface proteins, and autoradiography using a technetium (99m)Tc-labeling kit. Labeled red cells were infused intravenously in rats with brain tumors. Sickle cells preferentially accumulated in tumor relative to normal brain, with highest concentrations near the tumor / normal tissue boundary, whereas control normal red cells did not preferentially aggregate at the tumor periphery. This demonstrates the potential of sickle red blood cells to accumulate in the abnormal tumor vessel network, and the ability to detect their aggregation noninvasively and at high spatial resolution using MRI. The application of the noninvasive measurement of sickle cells for imaging tumor neovasculature, or as a delivery tool for therapy, requires further study.

Topics: Anemia, Sickle Cell; Animals; Autoradiography; Brain; Brain Neoplasms; Carboxylic Acids; Cell Line, Tumor; Contrast Media; Erythrocytes; Fluorescent Dyes; Gadolinium DTPA; Glioma; Humans; Magnetic Resonance Imaging; Male; Microscopy, Confocal; Neoplasm Transplantation; Rats; Rats, Inbred F344; Sodium Pertechnetate Tc 99m

A review of hospital admissions during 80 months revealed only 8 patients with episodes of priapism of approximately 400 pediatric male patients with sickle cell disease. The patients, who ranged in age from 5 to 19 years, underwent a 99mtechnetium penile scan, and 4 had a low and 4 had a high flow scan. Three cases resolved with hydration alone. Five patients received exchange transfusion of whom 3 subsequently underwent shunt procedures. One patient with a 5-year history of recurrent stuttering episodes was placed on transfusion therapy for 6 months and stuttering episodes have not recurred. One patient had a cerebrovascular accident 1 day after hospital discharge and another had priapism while on chronic transfusion therapy for a cerebrovascular accident. Each postpubertal patient had a severe clinical course; 1 had temporary impotence for 3 months and another had impotence at 2 weeks but was lost to followup. While 99mtechnetium penile scans may help clarify the severity of vascular stagnation, in our small group they were not helpful in predicting clinical course.

Topics: Adolescent; Adult; Anemia, Sickle Cell; Cerebrovascular Disorders; Child; Child, Preschool; Humans; Male; Priapism; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Penile scintigraphy with [99mTc]pertechnetate/99mTc-RBCs was performed in patients with sickle cell disease patients who had priapism to assess the role of this imaging procedure in directing the clinical management of these patients.. Fifteen studies were performed in 13 patients who were treated according to a protocol not dependent on the imaging results. The scintigraphic findings of penile vascular perfusion (stagnant or nonstagnant patterns) were collated retrospectively with the form of treatment needed for relief of the condition.. Four of five patients with the nonstagnant perfusion pattern responded to analgesics and intravenous hydration. Four of eight patients with the stagnant pattern did not require any aggressive interventions such as corporeal aspiration/irrigation, intracorporeal epinephrine or glans-cavernosa shunt.. Whereas the nonstagnant scintigraphic finding appeared to be a favorable indicator for conservative treatment, the stagnant finding was apparently noncontributory. In addition, no correlation was found between these two types of scintigraphic patterns and the subsequent sexual potency of these patients.

Topics: Adolescent; Adult; Anemia, Sickle Cell; Child; Child, Preschool; Erythrocytes; Follow-Up Studies; Humans; Impotence, Vasculogenic; Male; Penis; Priapism; Radionuclide Imaging; Retrospective Studies; Sodium Pertechnetate Tc 99m