Plasmapheresis. A therapeutic option in the management of heparin-associated thrombocytopenia with thrombosis.

Heparin-associated thrombocytopenia with thrombosis (HATT) is an uncommon syndrome that is estimated to occur in 1-5% of patients with heparin-induced thrombocytopenia. Early diagnosis requires careful clinical surveillance, and the management of these patients can be complex. Cessation of heparin therapy and substitution or addition of oral anticoagulants, antiplatelet agents, dextrans, and prostacyclin analogues have been advocated. The authors are aware of only two case reports in the literature that examine the use of plasmapheresis as a therapeutic alternative. The authors report a case of a 53-year-old white man who developed HATT after a single protamine-reversed exposure to heparin. Controlled platelet aggregation studies performed before and after apheresis sessions documented a dramatic response and rapid normalization of platelet number and function in the patient. The authors conclude that plasmapheresis could be a valuable adjunct in the successful management of patients with HATT. When done in conjunction with platelet aggregation studies, an objective measurement of therapeutic efficacy can be achieved.

The effects of radioisotopes used in nuclear medicine on diagnostic radioimmunoassay testing. Is there any significant interference?

The administration of radioisotopes for diagnostic nuclear medicine scans and therapeutic procedures is quite prevalent today. A period of interference with the counting of a radioimmunoassay [RIA] test may occur with the serum of a patient receiving an in vivo radionuclide that decays by gamma emission. Because the logistics of precounting all specimens may be cumbersome and prohibitive, it is important to determine the degree of this interference. In this study, the authors evaluate the potential interference of the most commonly used radioisotopes with RIA studies. For two months (March and August 1988) 10,650 patient serum specimens were counted for significant background gamma radiation before RIA testing. Forty-three patients, on whom 105 RIA tests were performed, were identified as having preassay gamma radiation in their serum. With the use of selective energy windows for each different interfering radionuclide, proportional determinations were made as to the amount of interfering gamma radiation spilling into the iodine 125 test marker window. It was shown that initial whole serum pretest gamma counts as high as 111,000 counts/minute did not significantly affect the results of the RIA. Because of the meticulous washing and decanting procedures required in modern RIA and the monoclonal nature of most antibodies used currently, it appears the degree of nonspecific binding of this potentially interfering radiation is minuscule. The energy level of cobalt 57, however, and many of the other commonly used radioisotopes, overlaps so closely that it is difficult to window for this interference. It is possible, therefore, that this distinction cannot be made and folate and vitamin B12 test systems using cobalt 57 markers may have to be routinely prescreened. The authors conclude that the requirement for prescreening of all RIA test samples for interfering gamma radiation is unnecessary (1987 CAP Commission on Laboratory Accreditation Inspection Checklist, Section VII, Question 07.0290).

Hepatic vein thrombosis (Budd-Chiari syndrome) in the microgranular variant of acute promyelocytic leukemia.

The microgranular form of acute promyelocytic leukemia (APL) was described in the late 1970s and adopted by the French, American, and British classification system in the early 1980s. Morphologically, this form shows distinct differences from the classic form of APL, but clinically it shares many of the same traits. Among these is the predilection for coagulopathies, including disseminated intravascular coagulation (DIC). This DIC has been associated with one previously reported case of fatal hepatic vein thrombosis (Budd-Chiari syndrome), in association with an untreated case of APL. The authors present a case of the microgranular variant of acute promyelocytic leukemia (FAB-M3V), with autopsy and electron microscopic evidence in support. It is important to recognize this variant form of APL and its association with hepatic vein thrombosis, because any successful attempt at therapy must be instituted early in the course of the disease.

Discovery rate of dysplasia and carcinoma of the uterine cervix in an urban medical center serving patients at high risk.

File analysis based on 98,970 Pap tests on 58,053 patients from the Martland Medical Center of CMDNJ and its clinics was performed. Discovery rates, period prevalence and incidence rates were calculated for categories of mild to moderate dysplasia through invasive carcinoma. An incidence rate of 27/100,000 for invasive carcinoma was obtained, which is lower than the national average. Period prevalence and incidence rates of dysplasias are both high and similar. This indicates that epidemiologic parameters may need to be studied further. The mean age for the mild to moderate dysplasia was 25.7 years, for moderate to severe dysplasia, 29.29 years and for CIS, 33.25 years. These data may imply that younger women, especially in the urban areas, are at much higher risk than previously expected.