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Biomedical subjects

H G Klein

Publications and source records attributed to H G Klein.

At least 127 records · Page 7Linked to original sources
PubMed1983

Selective removal of sickle cells with the IBM 2997 continuous flow blood cell separator.

Partial red cell exchange transfusion is used to manage several complications of sickle cell anemia. Reports have stressed the safety, ease, and speed of red cell exchange procedures performed with blood cell separators, but little information exists concerning operating conditions for the most efficient removal of hemoglobin S (HbS) containing cells. We performed 13 red blood cell exchange transfusions with the IBM 2997 continuous flow blood cell separator on two previously transfused adult homozygous (SS) sickle cell patients. We used both a single stage and a dual stage disposable pathway and varied rotor speed, collection port, and collection interface independently. The patients' baseline percentage HbS ranged from 28 to 64% (mean = 46%); post exchange values ranged from 19.1 to 46% (mean = 32%). Thirty-three of 34 specimens collected from the white cell or platelet port showed a higher percentage of HbS in the collection line compared to simultaneous patient samples. Mean enrichment was 9.4% (range = -4.0 to 35.5%). There was an inverse relationship between the hemoglobin concentration and the percentage of HbS in the collected specimens (p = 0.001; N = 45). Differential separation of sickle cells should decrease the volume of blood required for partial red cell exchange of selected SS patients.

Anemia, Sickle Cell↗
PubMed1983

A trial of immunotherapy in aplastic anemia and pure red cell aplasia.

Immunotherapy, consisting of lymphocyte depletion or plasmapheresis in combination with cyclophosphamide and prednisone, was employed in three patients with refractory pure red cell aplasia and six patients with aplastic anemia of various etiologies. All three patients with pure red cell aplasia responded to plasmapheresis. One patient with atypical aplastic anemia showed partial recovery following lymphocyte depletion; the other five patients showed no evidence of a clinical response. The effect of patients' sera or bone marrow on formation of myeloid or erythroid colonies by bone marrow from normal individuals was determined in vitro. A decline in serum inhibition of erythroid colony formation was observed in the patients with pure red cell aplasia following treatment. Any changes in serum inhibition were less marked or unrelated to treatment outcome in the patients with aplastic anemia, although the single patient who responded to lymphocyte depletion exhibited reversal of coculture bone marrow inhibition. Our experience suggests that in vitro assay methods may not adequately predict the response of patients with aplastic anemia to this form of immunotherapy, and furthermore clinical improvement was too sporadic for this treatment to be recommended. Plasmapheresis may be a useful adjunct in patients with pure red cell aplasia, but remissions may not be dramatic or sustained.

Adult↗
PubMed1983

Complications related to equipment and technique.

Automated cytapheresis, when performed by experienced operators using modern equipment, is remarkably free of adverse effects. A declining pattern of equipment failure and related problems has been recorded in the 220,000 procedures performed by the American Red Cross in the past 5 years. Other cytapheresis centers report similar findings. Current CBCS are safe and reliable, and defects in plastic disposables, while irritating, result in little danger to the donor. Operator vigilance and careful attention to the details of the procedure can eliminate the majority of serious potential complications that have been encountered to date.

Blood Component Removal↗
PubMed1983

Delayed hemorrhage after percutaneous liver biopsy.

Clinically significant hemorrhage immediately after percutaneous liver biopsy is an uncommon, although well-recognized risk of the procedure. However, hemorrhage from the biopsy site delayed a day or more after the procedure is a seldom-appreciated potential complication. Delayed hemorrhage from the liver biopsy site may go unsuspected; in fact, the patient may no longer be under direct medical surveillance. We describe two cases of such delayed hemorrhage which we attribute to intrahepatic hematoma at the site of biopsy. Neither patient had a prebiopsy contraindication to the procedure. One patient suffered a fatal intraperitoneal hemorrhage 15 days after liver biopsy, the other a massive, but nonfatal intrahepatic hemorrhage 41 hours after the procedure. In the first patient, a hemorrhagic diathesis developed in the immediate period after biopsy; no predisposition to hemorrhage could be identified in the latter patient, even retrospectively. The admittedly rare possibility of delayed hemorrhage should be considered whenever a liver biopsy is performed.

Adult↗
PubMed1983

Double-blind evaluation of plasmapheresis in schizophrenic patients: a pilot study.

Interest in the effects and possible mechanisms of hemodialysis on schizophrenic patients has led to a double-blind evaluation of the effects of plasmapheresis on symptoms of schizophrenia. Also, plasmapheresis was felt to be an invaluable tool for investigating the autoimmune theory of schizophrenia. Patients (n = 10) in the study fulfilled Research Diagnostic Criteria for schizophrenia and were randomly assigned to either sham or active plasmapheresis. They were blindly assessed by staff psychiatrists and nurses. Evaluation of the behavioral ratings revealed no significant decrease in psychosis for either the active or sham group. Also, no individual responding patient was identified. This finding complements our group's early negative results of a hemodialysis experiment and casts doubt on a simple autoimmune hypothesis of schizophrenia.

Adolescent↗
PubMed1983

The effect of bloodletting on exercise performance in a subject with a high-affinity hemoglobin variant.

We studied two young army recruits with erythrocytosis. One had a variant hemoglobin with high affinity for oxygen (hemoglobin Osler, also known as Fort Gordon and Nancy, beta 145 Tyr leads to Asp). The other had normal oxygen affinity and erythrocytosis of undetermined etiology. Both were asymptomatic. We studied exercise capacity on a cycle ergometer before and after hemodilution. In the subject with high oxygen affinity, hemodilution resulted in reduced maximal work and increased heart rate at every work level. In addition, minute ventilation and arterial lactic acid increased, while anaerobic threshold decreased, indicating diminished oxygen supply to tissues. In contrast, the subject with normal oxygen affinity had no significant changes in exercise performance after hemodilution. These results suggest that when blood oxygen affinity is high, loss of efficiency in tissue oxygenation can be expected after phlebotomy or hemodilution. Therefore, it may be useful to measure blood oxygen affinity and exercise performance in polycythemic subjects in whom such procedures are intended to ameliorate symptoms of hyperviscosity.

Adult↗
PubMed1983

Ex vivo selective isolation of young red blood cells using the IBM-2991 cell washer.

Transfusion-induced hemochromatosis is a major complication in the therapy of severe chronic anemia. Improvement of transfused cell survival with a reduction in transfusion frequency is one possible approach to this problem. Using continuous-flow centrifugation (CFC), young red blood cells (YRBC) with enhanced in vivo survival have been isolated, but the expense and donor time required with this technique prohibit its widespread use for patient support. We studied the use of the IBM 2991 cell washer (CW) to isolate YRBC ex vivo from previously collected donor blood. Age-dependent red cell separation could be achieved using this instrumentation. Autologous mean red cell half-life (RBC-T50) (n = 9) for the younger cell fractions was 43.9 +/- 7.8 days compared to 34.7 +/- 5.8 days for the older cell fractions (n = 6, p less than 0.05). Paired measurement of RBC-T50 for young and old fractions in three donors showed an average survival increase of 41% for the YRBC. Adequate quantities of YRBC with enhanced survival can be obtained with less cost and less donor stress using the CW system compared to CFC. This approach could improve the management of patients with chronic transfusion requirements and merits further examination.

Blood Transfusion↗
PubMed1982

Uncontrolled thrombocytosis in chronic myeloproliferative disorders.

A retrospective study was performed to examine the natural course of uncontrolled thrombocytosis associated with chronic myeloproliferative disorders. Thirty-eight patients with polycythaemia rubra vera (PV), myelofibrosis/myeloid metaplasia (MM), chronic myelogenous leukaemia (CML) or essential thrombocythaemia (ET) had platelet counts greater than 1000 X 10(9)/1 and were followed closely for a total of 246 patient years. Eleven of the patients experienced haemorrhagic episodes. Bleeding was twice as frequent in patients over 59 years old as in those younger and no bleeding occurred in those less than 51 years of age. There was no correlation between frequency of bleeding and extent of thrombocytosis. Bleeding events occurred concurrently with use of anti-inflammatory agents in 32% of episodes. The gastrointestinal tract was the most frequent site. Documented thrombotic events occurred in three patients, two of whom had PV with haematocrits greater than 53%. This study suggests that the thrombocytosis of myeloproliferative processes may pose a less serious threat than originally thought and that aggressive lowering of the platelet count may not be indicated in all cases.

Adult↗
PubMed1982

Partial red cell exchange transfusion in sickle cell disease.

Eighteen subjects with sickle cell disease underwent automated partial red cell exchanges while hospitalized as part of a research protocol. Using either a discontinuous-flow or a continuous-flow cell separator, we were able to accomplish a 50% exchange in an adult in approximately two hours. Transfusion of blood with an antigenic marker permitted rapid, on-line evaluation of exchange efficiency during the procedure. Ten subjects, in whom the hemoglobin concentration and blood volume were maintained nearly constant, were evaluated by submaximal exercise testing. Each subject realized a substantial improvement in exercise capacity; the mean anaerobic threshold increased from 64 to 115 watts and the mean work performed at a heart rate of 170/minute increased from 126 to 182 watts. Despite the expected acute increase in whole blood oxygen affinity in each patient, there was no clinical evidence of detrimental effects during or immediately following the procedure. Three of the subjects developed delayed hemolytic reactions within six days of exchange transfusion and presented with clinical features of painful sickle cell crises. When exchange transfusion is indicated, cell separators permit a rapid, effective and safe procedure.

Anemia, Sickle Cell↗
PubMed1982

Transfusions with young erythrocytes (neocytes) in sickle cell anemia.

Transfusion-induced hemochromatosis is a potential therapeutic complication of the management of sickle cell anemia. Selective transfusion with young erythrocytes (neocytes), which theoretically have a longer life-span than do regular donor red cells, could decrease transfusion frequency and reduce iron deposition in the sickle cell patient. Using blood cell separators, a method has been devised to prepare neocyte units for transfusion. Neocyte enrichment was evaluated by reticulocyte count and mean red cell age was estimated from erythrocyte pyruvate kinase, an age-dependent enzyme. These neocyte units have an average estimated men cell age of 30 days compared to 60 days for unfractionated units. Radiochromium studies in seven splenectomized thalassemia major patients revealed an average half-life of 47.4 days for neocytes stored in the frozen state compared to an average half-life of 29.5 days for standard frozen red cells. Neocyte aliquots collected from three normal, eusplenic donors had an average estimated mean cell age of 6.5 days and an average half-life of 57.2 days when reinfused. Neocyte units cost +300 to collect and process compared to $92 for frozen red cells, but use of neocyte units could reduce by one-half the transfusion requirement in transfusion-dependent patients.

Anemia, Sickle Cell↗
PubMed1981

Replacement therapy of alpha 1-antitrypsin deficiency. Reversal of protease-antiprotease imbalance within the alveolar structures of PiZ subjects.

The emphysema associated with the inherited serum deficiency of alpha 1-antitrypsin appears to result from an imbalance between neutrophil elastase and its major inhibitor within the alveolar structures. In the present study we assessed the feasibility of reversing this biochemical defect within the lung via parenteral replacement therapy with an alpha 1-antitrypsin concentrate of normal plasma. A 20--40% polyethylene glycol precipitate of pooled human donor plasma was used to obtain an enriched alpha 1-antitrypsin concentrate devoid of hepatitis B antigen and immunoglobulins. Using this material, five individuals with severe serum alpha 1-antitrypsin deficiency (PiZ phenotype) and advanced emphysema received 4 g of alpha 1-antitrypsin intravenously at weekly intervals for four doses. During this period of weekly replacement therapy alpha 1-antitrypsin serum levels were maintained at greater than or equal to 70 mg/dl, the level likely required for effective antielastase protection of the lung. In addition, assessment of lower respiratory tract antielastase activity by bronchoalveolar lavage demonstrated that parenteral replacement of alpha 1-antitrypsin resulted in establishment of effective antielastase activity within the alveolar structures. There were no untoward side effects consequent to this approach to the replacement therapy of alpha 1-antitrypsin. These results demonstrate that the parenteral replacement of alpha 1-antitrypsin provides a means of obtaining elastase-antielastase balance within the lung of individuals with this serum protease inhibitor deficiency.

Adult↗
PubMed1980

Intraoperative hemolysis. The initial manifestation of glucose-6-phosphate dehydrogenase deficiency.

Unexpected intraoperative hemolysis suggestive of a hemolytic transfusion reaction was the initial clinical manifestation of Mediterranean type glucose-6-phosphate dehydrogenase (G-6-PD) deficiency in a 50-year-old Indian man. There was no evidence for immune mediated hemolysis since no unexpected RBC antibodies were found, and results of the direct antiglobulin test remained negative. Analysis of preoperative blood specimens demonstrated complete absence of G-6-PD activity. No etiologic agent clearly associated with G-6-PD hemolysis could be identified. Testing for G-6-PD deficiency should be considered when unexpected hemolysis occurs intraoperatively.

Glucosephosphate Dehydrogenase Deficiency↗
PubMed1980

Delayed hemolytic transfusion reaction presenting as sickle-cell crisis.

Eighteen patients with sickle-cell disease underwent partial exchange transfusion. Three developed delayed hemolytic reactions, with selective disappearance of transfused cells. All reactions occurred within 6 days of transfusion, and patients presented with the clinical features of painful crises. The two most severe reactions were associated with antibodies to Jka. These patients developed fever, arthritis, and a clinical course suggesting serum sickness. In both patients, other alloantibodies had previously been seen. A fourth patient developed multiple alloantibodies, accelerated destruction of tranfused cells, but milder illness. Such reactions may be commoner than in appreciated and should be suspected when patients have recurrent or severe sickle crises after transfusion. Blood that is nonimmunogenic in antigen systems frequently associated with delayed hemolytic reactions (Rh, Kell, Duffy, and Kidd) is preferred for sickle-cell patients who lack these antigens, especially if these patients have previously demonstrated capability to form erythrocyte alloantibodies.

Adolescent↗
PubMed1980

Improved exercise performance after exchange transfusion in subjects with sickle cell anemia.

Ten patients with sickle cell anemia underwent partial exchange transfusion with hemoglobin-A-containing cells using a technique that allowed hemoglobin concentration and blood volume to remain constant. The mean fraction of hemoglobin-A in these patients increased from 9% to 55%, but the mean hemoglobin concentration increased by only 1.44 g/dl. The exchange resulted in a large improvement in submaximal exercise capacity: the mean of the anaerobic threshold (the work at which lactic acid begins to accumulate in the blood) increased from 68 to 114 W. The mean work performed at a heart rate of 170/min, an estimation of maximal work capacity, increased from 128 to 187 W. Improved exercise performance after partial exchange transfusion may result from the superior flow properties of hemoglobin-A-containing red cells. Furthermore, we believe that exercise testing in sickle cell anemia has great potential utility as a means to monitor therapy and to evaluate the benefits of exchange transfusion.

Adult↗