On-label compared to off-label four-factor prothrombin complex concentrate use: a retrospective, observational study

BACKGROUND

Four-factor prothrombin complex concentrate (4F-PCC) is US Food and Drug Administration approved for the urgent reversal of coagulation factor deficiency induced by a vitamin K antagonist complicated by acute major bleeding or in situations in which invasive procedures are urgently needed. Although recent evidence suggests the superiority of 4F-PCC over plasma for on-label indications, the off-label use of 4F-PCC has not been rigorously studied.

STUDY DESIGN AND METHODS

Eighty-nine patients receiving 4F-PCC at a single institution from July 2016 to December 2017 were retrospectively analyzed. Two cohorts, "On-Label" and "Off-Label" uses of 4F-PCC, were evaluated, comparing patient characteristics, blood utilization, and clinical outcomes including in-hospital mortality.

RESULTS

Patients receiving 4F-PCC for off-label reasons (n = 46) were younger and sicker compared to those receiving 4F-PCC for on-label reasons (n = 43). Notably, the mortality rate for off-label use was approximately twofold greater than the mortality rate for on-label use (26 of 46 [56.5%] vs. 12 of 43 [27.9%]; p = 0.006). Patients receiving 4F-PCC for off-label reasons received more units per patient of each blood component than their on-label counterparts. The average cost estimate per patient for 4F-PCC was similar (approx. $4300) in each cohort.

CONCLUSION

4F-PCC is an effective but expensive treatment option for those requiring urgent reversal of vitamin K antagonist-induced coagulopathy. However, providers should be conscious of the high costs and questionable efficacy when using 4F-PCC off-label.

Implementing a Health System-wide Patient Blood Management Program with a Clinical Community Approach

BACKGROUND

Patient blood management programs are gaining popularity as quality improvement and patient safety initiatives, but methods for implementing such programs across multihospital health systems are not well understood. Having recently incorporated a patient blood management program across our health system using a clinical community approach, we describe our methods and results.

METHODS

We formed the Johns Hopkins Health System blood management clinical community to reduce transfusion overuse across five hospitals. This physician-led, multidisciplinary, collaborative, quality-improvement team (the clinical community) worked to implement best practices for patient blood management, which we describe in detail. Changes in blood utilization and blood acquisition costs were compared for the pre- and post-patient blood management time periods.

RESULTS

Across the health system, multiunit erythrocyte transfusion orders decreased from 39.7 to 20.2% (by 49%; P < 0.0001). The percentage of patients transfused decreased for erythrocytes from 11.3 to 10.4%, for plasma from 2.9 to 2.2%, and for platelets from 3.1 to 2.7%, (P < 0.0001 for all three). The number of units transfused per 1,000 patients decreased for erythrocytes from 455 to 365 (by 19.8%; P < 0.0001), for plasma from 175 to 107 (by 38.9%; P = 0.0002), and for platelets from 167 to 141 (by 15.6%; P = 0.04). Blood acquisition cost savings were $2,120,273/yr, an approximate 400% return on investment for our patient blood management efforts.

CONCLUSIONS

Implementing a health system-wide patient blood management program by using a clinical community approach substantially reduced blood utilization and blood acquisition costs.

Immunoglobulin clonality analysis. Resolution of ambiguities in immunofixation electrophoresis results by high-resolution, two-dimensional electrophoretic analysis of paraprotein bands eluted from agarose gels

This article describes evaluation of the clonality of origin of immunoglobulin (Ig) chains by strategies that include qualitative analysis of paraproteins with high-resolution, two-dimensional electrophoresis (2DE) and silver staining. This approach is helpful in evaluating specimens in which standard immunoelectrophoresis or immunofixation electrophoresis (IFE) techniques do not provide definitive Ig typing results. One method the authors developed involves a "band elution" procedure, in which proteins present in high-resolution agarose gel electrophoresis bands are cut from the agarose gel, eluted with a denaturing buffer, and subjected to 2DE. The microheterogeneity patterns of the Ig light chains, heavy chains, or both are evaluated for their relationship regarding mass, charge, and, by inference, number of genes of origin. When necessary, determination of charge relationships may be aided by urea-mediated carbamylation of lysine residues, which introduces single-charge shifts to the individual protein subunits. Overall, these adjunctive techniques are particularly useful in cases with multiple bands of identical immunologic types (eg, several IgG1 bands) on IFE before and after sulfhydryl reduction (with dithiothreitol or 2-mercaptoethanol). The authors present procedural details and examples of the 2DE band elution patterns of serum and urine samples from four patients with B-cell dyscrasias, including the first reported case of POEMS syndrome with biclonal gammopathy, to the best of their knowledge.

Rapid thawing of fresh frozen plasma in two-liter bags

The authors hypothesized that plasma could be rapidly thawed in two-liter Transfer Pack Units, because of their greater surface area (993 cm2) compared to standard satellite bags (348 cm2) of Blood Pack Units (both from Fenwal, Baxter Healthcare Corp, Deerfield, IL). Five units of FFP were prepared in each bag. The Sterile Connection Device (DuPont, Wilmington, DE) was used to transfer plasma from the satellite to transfer pack units, and these were put in metal canisters before all units were frozen at -65 degrees C. Thawing time was 4.8 +/- 1.3 (SD) minutes and 15 +/- 3.2 (SD) min. for units prepared in modified and standard methods respectively (t = 6.33, P less than .01). The thermal rate constants were calculated as 0.0034 and 0.0033 for the two methods. The finding of similar values substantiate the theory that thawing time is related to the volume to surface area ratio.

Alterations in lactate dehydrogenase isoenzyme patterns after therapy with streptokinase or streptococcal infection

Serum samples from patients receiving intravenous streptokinase were examined for evidence of interaction in vivo between streptokinase and lactate dehydrogenase (EC 1.1.1.27; LD). We found that this treatment produced a band of LD activity that remained at the electrophoretic origin of LD isoenzyme analysis. Treatment with tissue plasminogen activator produced no such band. The streptokinase-LD complex could be removed from serum by ultracentrifugation. It remained in the circulation for as long as 48 h after streptokinase infusion. A similar phenomenon was observed in a case of pneumococcal sepsis. Examination of supernates from both cultures of several species of Gram-positive cocci revealed interactions between human LD and Streptococcus groups A and C and also Streptococcus pneumoniae. Evidently streptokinase can form complexes with LD in vivo after either streptokinase therapy or infection, with consequent alteration of the LD isoenzyme pattern.

Alterations in lactate dehydrogenase isoenzyme patterns after therapy with streptokinase or streptococcal infection

Serum samples from patients receiving intravenous streptokinase were examined for evidence of interaction in vivo between streptokinase and lactate dehydrogenase (EC 1.1.1.27; LD). We found that this treatment produced a band of LD activity that remained at the electrophoretic origin of LD isoenzyme analysis. Treatment with tissue plasminogen activator produced no such band. The streptokinase-LD complex could be removed from serum by ultracentrifugation. It remained in the circulation for as long as 48 h after streptokinase infusion. A similar phenomenon was observed in a case of pneumococcal sepsis. Examination of supernates from both cultures of several species of Gram-positive cocci revealed interactions between human LD and Streptococcus groups A and C and also Streptococcus pneumoniae. Evidently streptokinase can form complexes with LD in vivo after either streptokinase therapy or infection, with consequent alteration of the LD isoenzyme pattern.

Streptokinase binds to lactate dehydrogenase subunit-M, which shares an epitope with plasminogen

The bacterial thrombolytic agent streptokinase binds to human, porcine, and chicken lactate dehydrogenase (EC 1.1.1.27; LD) isoenzyme subunit M, but not to the H or C subunits. There is amino acid sequence homology between LD and the streptokinase binding site on plasminogen to account for this interaction that results in the formation of high-molecular-mass complexes in serum that contain LD activity. Binding of highly immunogenic streptokinase with LD may lead to induction of anti-LD autoantibodies, known to occur in some patients after therapeutic administration of streptokinase for treatment of acute myocardial infarction. This interaction may also be a general mechanism for inducing autoimmunity against other proteins that share the streptokinase binding epitope.

Streptokinase binds to lactate dehydrogenase subunit-M, which shares an epitope with plasminogen

The bacterial thrombolytic agent streptokinase binds to human, porcine, and chicken lactate dehydrogenase (EC 1.1.1.27; LD) isoenzyme subunit M, but not to the H or C subunits. There is amino acid sequence homology between LD and the streptokinase binding site on plasminogen to account for this interaction that results in the formation of high-molecular-mass complexes in serum that contain LD activity. Binding of highly immunogenic streptokinase with LD may lead to induction of anti-LD autoantibodies, known to occur in some patients after therapeutic administration of streptokinase for treatment of acute myocardial infarction. This interaction may also be a general mechanism for inducing autoimmunity against other proteins that share the streptokinase binding epitope.

Specificity of autoantibodies to lactate dehydrogenase isoenzyme subunits

We studied serum from 12 unrelated patients with variant electrophoretic patterns for lactate dehydrogenase (EC 1.1.1.27; LD) isoenzymes characteristic of LD-immunoglobulin complexes. Immunoglobulin class was identified in four cases. In all 12 cases, mixing the patient's serum with control serum altered the mobility of normal LD isoenzymes to that of the variant. To determine antigenic specificity, we mixed ammonium sulfate-precipitated fractions of patient's samples with purified LD1 (H tetramer) or LD5 (M tetramer) prepared by anion-exchange chromatography. In six cases the fractionated antibody displayed a pure M-subunit specificity. In four cases it acted against both M tetramers and H tetramers, and in two cases the antibody affected the migration only of LD isoenzymes containing both M and H subunits (i.e., hybrid isoenzymes). Depending on the relative excess of antibody or LD5 in such mixtures, various different anomalous electrophoretic patterns were produced. These results indicate that apparent differences between variant LD isoenzyme patterns in whole serum of different individuals can arise from autoantibodies with similar reactivities being present in various ratios of antigen to antibody.

Specificity of autoantibodies to lactate dehydrogenase isoenzyme subunits

We studied serum from 12 unrelated patients with variant electrophoretic patterns for lactate dehydrogenase (EC 1.1.1.27; LD) isoenzymes characteristic of LD-immunoglobulin complexes. Immunoglobulin class was identified in four cases. In all 12 cases, mixing the patient's serum with control serum altered the mobility of normal LD isoenzymes to that of the variant. To determine antigenic specificity, we mixed ammonium sulfate-precipitated fractions of patient's samples with purified LD1 (H tetramer) or LD5 (M tetramer) prepared by anion-exchange chromatography. In six cases the fractionated antibody displayed a pure M-subunit specificity. In four cases it acted against both M tetramers and H tetramers, and in two cases the antibody affected the migration only of LD isoenzymes containing both M and H subunits (i.e., hybrid isoenzymes). Depending on the relative excess of antibody or LD5 in such mixtures, various different anomalous electrophoretic patterns were produced. These results indicate that apparent differences between variant LD isoenzyme patterns in whole serum of different individuals can arise from autoantibodies with similar reactivities being present in various ratios of antigen to antibody.

Characterization of apparent lactate dehydrogenase isoenzyme 6: a lactate-independent dehydrogenase

We found in a prospective study of lactate dehydrogenase isoenzyme 6 (LD6) in human tissues obtained at autopsy that LD6 was usually present in liver when death was preceded by prolonged hypotension or impaired ventilation but not in cases of sudden death. Other organs containing LD6 were kidney and spleen. LD6 is heat stable, differs from H-subunit-containing LD isoenzymes by pyruvate resistance, differs from M-subunit-containing LD isoenzymes by immunoprecipitation, and is distinct from spermatic LDX. LD6 from liver extracts acted without lactate as substrate and could be enhanced by ethanol added to the substrate. These results indicate that LD6 is not a true lactate dehydrogenase, and that it frequently appears in severe liver injury.

Characterization of apparent lactate dehydrogenase isoenzyme 6: a lactate-independent dehydrogenase

We found in a prospective study of lactate dehydrogenase isoenzyme 6 (LD6) in human tissues obtained at autopsy that LD6 was usually present in liver when death was preceded by prolonged hypotension or impaired ventilation but not in cases of sudden death. Other organs containing LD6 were kidney and spleen. LD6 is heat stable, differs from H-subunit-containing LD isoenzymes by pyruvate resistance, differs from M-subunit-containing LD isoenzymes by immunoprecipitation, and is distinct from spermatic LDX. LD6 from liver extracts acted without lactate as substrate and could be enhanced by ethanol added to the substrate. These results indicate that LD6 is not a true lactate dehydrogenase, and that it frequently appears in severe liver injury.