Complications and difficulties in radiolabelling blood cells: a review.

The radiolabelling of blood cells is occasionally problematical. Difficulties occur either with the labelling process itself or after the labelled cells have been reinjected. Failure to label may be due to pharmaceutical factors, such as difficulties with collecting sufficient cells, sedimentation problems or instability of the cell chelator, or problems may arise which are patient-related, such as patient medication or the presence of disease. A number of surveys have been undertaken to assess the possibility of drug interference as a cause of problems with labelling or biodistribution. Leukocyte labelling difficulties occurred in patients who were on multi-drug therapy whose drug regimes included combinations of prednisolone, azathioprine, cyclosporin, ranitidine, nifedipine, cyclophosphamide and naproxen. While a direct causal relationship has not been established, the known adverse effects of the drugs on white cell function and kinetics suggest that patient medication could be an important factor in leukocyte labelling. Red cell labelling difficulties have occurred from time to time and published reports implicate pharmaceutical factors, such as choice of anti-coagulant, level of stannous ion and oxidation of technetium-99m (99Tcm). Patient-related factors such as the presence of disease or drugs have also been implicated. A survey of red cell problems and patient medication showed that difficulties occurred in patients who were treated with combinations of nifedipine, etoposide, idarubicin and cefataxime. In-vitro testing of a number of drugs with 99Tcm-labelled red cells has demonstrated that cyclosporin, nifedipine, verapamil, hydralazine, propranolol, digoxin and Teflon cannulae can affect labelling.

[Stem cell apheresis--experiences in children]. / Stammzellapherese--Berner Erfahrungen bei Kindern.

Stem cell apheresis, as a means to support patients during aplasia, has become an important support in the management of patients with various malignant diseases in need for heavy therapeutic regimens. Progress in this field is due, among other reasons, to better knowledge of pathophysiology in haematopoiesis and of the functioning of cytokines. Furthermore, the technical feasibility of apheresis has been improved to such an extent as to allow for collection of a stem cell-containing fraction almost in pure form. Our experience with stem cell apheresis is relatively short but includes also children between the ages of 1 and 21 years (median: 5 1/2 years). Whereas the clinical results have been published elsewhere, we here report our experience in terms of safety, using the Fresenius AS 104 machine.

Comparison of the side effects of therapeutic cytapheresis and those of other types of hemapheresis.

The side effects of a series of 2418 hemapheresis procedures performed in a total of 570 subjects (patients and donors) are described. Patients with various diseases were subjected to plasmapheresis (926 procedures in 181 patients) or cytapheresis (305 procedures in 89 patients). One hundred twelve plasmapheresis procedures and 1075 of cytaphereses were also performed in 300 blood donors. A total of 225 complications involving 107 patients (39.6%) occurred during 196 (15.9%) therapeutic procedures. Among the blood donors only 45 complications, involving 35 patients (11.6%) occurred during 45 procedures (4.2%). The complications seen with therapeutic plasmaphereses were circulatory disturbances (38% of all those observed), citrate reactions (27%), technical problems (20%), allergic reactions (9%) and miscellaneous complications (6%). Therapeutic cytaphereses were complicated by citrate reactions (44%), technical problems (25%), circulatory disturbances (14%), allergic reactions (11%) and miscellaneous complications (6%). Complications in the blood donor group included circulatory disturbances (51%), technical problems (36%) and various other problems (13%). No infectious complications or deaths were observed. The probability that adverse reactions will occur depends on the condition of the patient, the frequency of the sessions and the volume of fluid exchanged. Evaluation of the main risk factors, use of less intensive protocols and interruption of the session at the first sign of disturbances will help improve patient tolerance of these procedures.

In vitro study of immunologic changes in long-term cytapheresis donors.

Several in vitro measurements of immune function were examined retrospectively in a population of active long-term cytapheresis donors (group I; n = 50) and the results were compared to age- and sex-matched controls (group II; n = 50) who had donated only whole blood. In group I, significantly different mean absolute lymphocyte counts (P = .0025), total T-cells (P = .0026) and T-helper cells (P less than .0001), and helper-to-suppressor ratios (P = .0279) were present. No differences were noted between the two groups for peripheral blood mean B-cell count, T-suppressor numbers, lymphocyte responsiveness to mitogens or alloantigen, and serum immunoglobulin level. The reduced mean absolute lymphocyte count in group I was due to the reduction in T-helper cell numbers and accounted for the imbalance in the helper-to-suppressor ratio. These disturbances are currently unexplained and, while no clinical consequences have so far become evident, there is a need to continuously monitor the immunologic status of cytapheresis donors. It is also important to determine whether reversal of the defects occurs and, if so, over what time interval.

[Side-effects of continuous and discontinuous cytapheresis]. / Vedl'ajsie úcinky kontinuálnej a diskontinuálnej cytaferézy.

The authors evaluate the incidence of complications in 767 cytapreheses made on two types of blood cell separators. Complications, incl. technical problems before cytapheresis proper, were encountered more frequently during work with the discontinuous blood cell separators Haemonetics model 30 (27.%) than during work with the continuous automatic blood cell separator Fenwal CS 3000 (13.2%). Most frequently collapse and symptoms of hypocalcaemia were involved. Serious reactions account only for 7.6 and 4.4% of all reactions. The authors discuss the causes and possible prevention of complications during cytapheresis. With regard to the assessed results cytaprehesis by means of a separator can be considered a safe method in blood donors.