Therapeutic Apheresis-State of the Art in the Year 2005

Short and long-term outcomes of children with autoimmune congenital heart block treated with a combined maternal-neonatal therapy. A comparison study

OBJECTIVE

The short and long-term outcomes of children with anti-Ro/La-related congenital heart block treated with a combined maternal-neonatal therapy protocol were compared with those of controls treated with other therapies.

STUDY DESIGN

Sixteen mothers were treated during pregnancy with a therapy consisting of daily oral fluorinated steroids, weekly plasma exchange and fortnightly intravenous immunoglobulins and their neonates with intravenous immunoglobulins (study group); 19 mothers were treated with fluorinated steroids alone or associated to intravenous immunoglobulins or plasma exchange (control group).

RESULT

The combined-therapy children showed a significantly lower progression rate from 2nd to 3rd degree block at birth, a significant increase in heart rate at birth and a significantly lower number of pacemaker implants during post-natal follow-up with respect to those treated with the other therapies.

CONCLUSION

The combined therapy produced better short and long term outcomes with respect to the other therapies studied.

Plaque Regression and Endothelial Progenitor Cell Mobilization With Intensive Lipid Elimination Regimen (PREMIER)

BACKGROUND

Low-density lipoproteins (LDLs) are removed by extracorporeal filtration during LDL apheresis. It is mainly used in familial hyperlipidemia. The PREMIER trial (Plaque Regression and Progenitor Cell Mobilization With Intensive Lipid Elimination Regimen) evaluated LDL apheresis in nonfamilial hyperlipidemia acute coronary syndrome patients treated with percutaneous coronary intervention.

METHODS

We randomized 160 acute coronary syndrome patients at 4 Veterans Affairs centers within 72 hours of percutaneous coronary intervention to intensive lipid-lowering therapy (ILLT) comprising single LDL apheresis and statins versus standard medical therapy (SMT) with no LDL apheresis and statin therapy alone. Trial objectives constituted primary safety and primary efficacy end points and endothelial progenitor cell colony-forming unit mobilization in peripheral blood.

RESULTS

Mean LDL reduction at discharge was 53% in ILLT and 17% in SMT groups (P<0.0001) from baseline levels of 116.3±34.3 and 110.7±32 mg/dL (P=0.2979), respectively. The incidence of the primary safety end point of major peri-percutaneous coronary intervention adverse events was similar in both groups (ILLT, 3; SMT, 0). The primary efficacy end point, percentage change in total plaque volume at 90 days by intravascular ultrasound, on average decreased by 4.81% in the ILLT group and increased by 2.31% in the SMT group (difference of means, -7.13 [95% CI, -14.59 to 0.34]; P=0.0611). The raw change in total plaque volume on average decreased more in the ILLT group than in the SMT group (-6.01 versus -0.95 mm³; difference of means, -5.06 [95% CI, -11.61 to 1.48]; P=0.1286). Similar results were obtained after adjusting for participating sites, age, preexisting coronary artery disease, diabetes mellitus, baseline LDL levels, and baseline plaque burden. There was robust endothelial progenitor cell colony-forming unit mobilization from baseline to 90 days in the ILLT group (P=0.0015) but not in SMT (P=0.0844).

CONCLUSIONS

PREMIER is the first randomized clinical trial to demonstrate safety and a trend for early coronary plaque regression with LDL apheresis in nonfamilial hyperlipidemia acute coronary syndrome patients treated with percutaneous coronary intervention. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01004406 and NCT02347098.

Cascade plasmapheresis as a desensitization strategy for patients undergoing ABO incompatible living donor liver transplantation (ABOi LDLT): A single center experience

BACKGROUND AND AIM

The reduction of antibody titres (AT's) to a safe level is essential pre-requisite for patients awaiting ABO-incompatible liver transplantation (ABOi LT). We report our experience of performing cascade plasmapheresis (CP) on 2 different apheresis platforms (COBE Spectra and Spectra Optia) as a desensitization strategy for patients undergoing ABOi LT in our centre.

METHODS

This retrospective observational study was conducted on patients who underwent CP included in the desensitization protocol for ABOi LDLT. CP/conventional TPE was performed (daily/alternate day with daily estimation of AT) until a target titre of ≤ 8 was achieved.

RESULTS

During the study period, 4 patients (mean age 46.7 years; 100% males) underwent desensitization for ABOi LDLT with baseline AT (combined IgM and IgG) ranging from 64 to 512. A total of 15 CP sessions (range 2 - 6) were performed with a median of 3.5 sessions/patient. Desensitization rate was 100%. Only 1 patient underwent conventional TPE in the post-transplant due to rise in AT level to 64 (post-operative day 8). Average post-operative length of stay was 49 days (range 30 - 105). None of the patients experienced any episode of rejection (repeat liver biopsy). On follow up (1 year), 2 patients were alive and doing well, while other 2 patients succumbed during their hospital stay due to sepsis.

CONCLUSION

In our limited experience, the use of CP was safe and effective desensitization strategy for patients undergoing ABOi LDLT.

Extracorporeal Elimination of Circulating Pegylated Liposomal Doxorubicin (PLD) to Enhance the Benefit of Cytostatic Therapy in Platinum-Resistant Ovarian Cancer Patients

Ovarian cancer is the fifth most common malignancy in the world's female population and with the highest lethality index among gynecological tumors. The prognosis of metastatic disease is usually poor, especially in platinum-resistant cases. There are several options for the treatment of metastatic disease resistant to platinum derivates (e.g. paclitaxel, topotecan and pegylated liposomal doxorubicin), all of which are considered equipotent. Pegylated liposomal doxorubicin (PLD) is a liposomal form of the anthracycline antibiotic doxorubicin. It is characterized by more convenient pharmacokinetics and a different toxicity profile. Cardiotoxicity, the major adverse effect of conventional doxorubicin, is reduced in PLD as well as hematotoxicity, alopecia, nausea and vomiting. Skin toxicity and mucositis, however, emerge as serious issues since they represent dose and schedule-limiting toxicities. The pharmacokinetics of PLD (prolonged biological half-life and preferential distribution into tumor tissue) provide new possibilities to address these toxicity issues. The extracorporeal elimination of circulating liposomes after PLD saturation in the tumor tissue represents a novel and potent strategy to diminish drug toxicity. This article intends to review PLD characteristics and the importance of extracorporeal elimination to enhance treatment tolerance and benefits.

Response to Plasmapheresis Measured by Angiogenic Factors in a Woman with Antiphospholipid Syndrome in Pregnancy

An imbalance of angiogenic and antiangiogenic placental factors such as endoglin and soluble fms-like tyrosine kinase 1 has been implicated in the pathophysiology of preeclampsia. Extraction of these substances by plasmapheresis might be a therapeutical approach in cases of severe early-onset preeclampsia. Case Report. A 21-year-old primigravida with antiphospholipid syndrome developed early-onset preeclampsia at 18 weeks' gestation. She was treated successfully with plasmapheresis in order to prolong pregnancy. Endoglin and sflt-1-levels were measured by ELISA before and after treatment. Endoglin levels decreased significantly after treatment (p < 0.05) and showed a significant decrease throughout pregnancy. A rerise of endoglin and sflt-1 preceded placental abruption 4 weeks before onset of incident. Conclusion. Due to the limited long-term therapeutical possibilities for pregnancies complicated by PE, plasmapheresis seems to be a therapeutical option. This consideration refers especially to pregnancies with early-onset preeclampsia, in which, after first conventional treatment of PE, prolongation of pregnancy should be above all.

Fibrinogen reduction and bleeding complications in plasma exchange, immunoadsorption and a combination of the two

BACKGROUND

Immunoadsorption (IAS) and therapeutic plasma exchange (TPE) are considered safe although fibrinogen is removed. To date no comparison of fibrinogen reduction and associated risk of bleeding in apheresis exists.

METHODS

Retrospective analysis of TPE, three IAS adsorbers, and combined TPE/IAS regarding fibrinogen reduction and bleeding incidence in 67 patients (1,032 treatments).

RESULTS

TPE and TPE/IAS reduced fibrinogen by 64 ± 11% and 58 ± 9%, leading to concentrations <100 mg/dl in 20 and 17% of treatments, respectively. IAS decreased fibrinogen less than TPE (26 ± 6%, p < 0.0001), resulting in fibrinogen concentrations <100 mg/dl in 1% of treatments. The processed volume correlated with reduction in TPE (r = 0.64, p < 0.01), but not in IAS. Bleeding occurred in 1.3% (IAS), 2.3% (TPE) and 3.1% (TPE/IAS) of treatments.

CONCLUSION

Hypofibrinogenemia occurs in 20% of patients after TPE and TPE/IAS, but rarely after IAS. IAS removes fibrinogen independently of volume processed. Overall, bleeding is rare in apheresis.

Pharmacokinetic profile of voriconazole in a critically ill patient on therapeutic plasma exchange

BACKGROUND

Extracorporeal removal of drugs during therapeutic plasma exchange (TPE) can lead to decreased efficacy, as shown in several reports discussing altered pharmacokinetics (PKs) of antibiotics during TPE. In particular, drugs with a low volume of distribution or a high protein binding are susceptible to extracorporeal removal, as these drugs remain substantially within the intravascular space. No information is known about antifungal drug removal during TPE. We report the PKs of voriconazole in a critically ill patient undergoing TPE.

METHODS

A 61-year-old man, presenting with catastrophic antiphospholipid syndrome for which TPE was started, developed probable pulmonary invasive aspergillosis. Intravenous voriconazole was started. Blood samples were taken under steady state conditions to calculate PK parameters of voriconazole, both with and without TPE.

RESULTS

PK parameters (area under the curve, Cl, Vd, and t1/2) were equivalent on both days. Voriconazole has a distribution volume of 4.5 L/kg and a protein binding of 58%, suggesting that drug removal during TPE would not be clinically significant. Our data support this assumption.

CONCLUSION

Based on our findings, it seems that TPE does not alter the PK behavior of voriconazole. Voriconazole dosages should not be adjusted during TPE.

The selective therapeutic apheresis procedures

Selective apheresis procedures have been developed to target specific molecules, antibodies, or cellular elements in a variety of diseases. The advantage of the selective apheresis procedures over conventional therapeutic plasmapheresis is preservation of other essential plasma components such as albumin, immunoglobulins, and clotting factors. These procedures are more commonly employed in Europe and Japan, and few are available in the USA. Apheresis procedures discussed in this review include the various technologies available for low-density lipoprotein (LDL) apheresis, double filtration plasmapheresis (DFPP), cryofiltration, immunoadsorption procedures, adsorption resins that process plasma, extracorporeal photopheresis, and leukocyte apheresis.

Newly designed CRRT membranes for sepsis and SIRS--a pragmatic approach for bedside intensivists summarizing the more recent advances: a systematic structured review

In recent years, after all the attention has been focused on the dose for continuous renal replacement therapy (CRRT) in sepsis and systemic inflammation response syndrome (SIRS), the relatively negative results of all those studies did urge our expectations on new approaches regarding CRRT in sepsis and SIRS. So far, after the failure of the major randomized studies on dose, attention is now drawn to new membranes that could better eliminate massive amounts of unbound mediators in wider spectrum and also in greater magnitude Nevertheless, for septic acute kidney injury, the recommended dose will remain 35 ml/kg/h until the IVOIRE (hIgh VOlume in Intensive Care) study will be published. In this new armamentarium, we have distinguished the first tools that can still be called membranes ranging from AN69 Surface Treated (ST), SEPTEX, polymethylmetacrylate, to Oxiris that can still run with a CRRT device. Polymyxin B is still a kind of membrane although it has a larger surface, but it can run in a hemoperfusion system and is also much more selective. Adsorptive columns and sorbents are not anymore membranes but are seen as cartridges as the surface is extremely huge when compared with that of membranes (more than 500 m). They can still run in a hemoperfusion device. At the very end, we do have apheresis or selective plasma exchange (also very close to sorbents and columns) but we have very few data up to now regarding sepsis. Regarding spectrum, CytoSorb seems to be very promising although it is not able to capture endotoxin and IL-10. Oxiris is also promising as it can capture endotoxin and cytokines. AN69 ST is very powerful to capture numerous cytokines and especially high-mobility group box 1 protein (a very upstream cytokine). Polymethylmetacrylate has also the power to capture endotoxin and numerous other cytokines probably with a larger magnitude than Oxiris although this is not proven. Lastly, high-porosity membranes (Septex) may play a role especially when used in continuous venovenous hemodialysis mode. At the end, if we look for a more enlarged spectrum and a higher magnitude, CytoSorb might be seen as the most promising although not having the ability to fix endotoxin. Future studies will tell us which membrane or sorbent will be most useful in the adjunctive treatment for sepsis.

Rapid reduction of hepatitis C virus-Core protein in the peripheral blood improve the immunological response in chronic hepatitis C patients

AIM

  The extracellular hepatitis C virus (HCV)-antigen, including HCV-Core protein, can suppress immune cells. Recently, the efficacy of double filtration plasmapheresis (DFPP) for chronic hepatitis C (CHC) was reported. However, the mechanism of efficacy of DFPP might not be only the reduction of HCV but also the effect of immune cells via direct and/or indirect mechanisms. The aim of this study is to analyze the virological and immunological parameters of difficult-to-treat HCV patients treated with DFPP combined with Peg-interferon and RBV (DFPP/Peg-IFN/RBV) therapy.

METHODS

  Twelve CHC patients were enrolled and treated with DFPP/Peg-IFN/RBV therapy. The immunological, virological and genetic parameters were studied.

RESULTS

  All patients (4/4) treated with the major IL28B allele (T/T) could achieve complete early virological response (EVR). The amounts of HCV-Core antigen in the peripheral blood of EVR patients treated with DFPP/Peg-IFN/RBV rapidly declined in comparison to those of late virological response (LVR) patients treated with DFPP/Peg-IFN/RBV and EVR patients treated with Peg-IFN and RBV (Peg-IFN/RBV). The amount of IFN-γ produced from peripheral blood gradually increased. On the other hand, the amount of IL10 gradually decreased in the EVR patients. The frequencies of HCV-Core binding on CD3+ T cells rapidly declined in EVR patients treated with DFPP/Peg-IFN/RBV therapy. Moreover, the distributions of activated CD4(+) and CD8(+) T cells and CD16-CD56 high natural killer cells were significantly changed between before and after DFPP.

CONCLUSIONS

  The rapid reduction of HCV-Core antigens and changes in the distribution of lymphoid cells could contribute to the favorable immunological response during DFPP/Peg-IFN/RBV therapy.

Kinetic targeting of pegylated liposomal doxorubicin: a new approach to reduce toxicity during chemotherapy (CARL-trial)

BACKGROUND

The therapeutic success of chemotherapeutic agents is often limited by severe adverse effects. To reduce toxicity of these drugs, nanoscale particle-based drug delivery systems (DDS) are used. DDS accumulate to some extent in tumor tissues, but only a very small portion of a given dose reaches this target. Accumulation of DDS in tumor tissues is supposed to be much faster than in certain other tissues in which side effects occur ("Kinetic Targeting"). Once saturation in tumor tissue is achieved, most of the administered DDS still circulate in the plasma. The extracorporeal elimination of these circulating nanoparticles would probably reduce toxicity.

METHODS

For the CARL-trial (Controlled Application and Removal of Liposomal chemotherapeutics), pegylated liposomal doxorubicin (PLD) was used as chemotherapeutic agent and double filtration plasmapheresis (DFPP) was performed for extracorporeal elimination of liposomes. PLD was given as 40 mg/m2 every 3 weeks in combination with vinorelbine 2 × 25 mg/m2 (neoadjuvant treatment of breast cancer, 12 patients), or as 40 mg/m2 every 4 weeks (recurrent ovarian cancer, 3 patients). Primary endpoints were the efficiency and safety profile of DFPP, and secondary endpoints were side effects and tumor response.

RESULTS

DFPP eliminated ~62% of circulating PLD, corresponding to ~45% of the total dose (n = 57 cycles). AUC of doxorubicin was reduced by 50%. No leakage of doxorubicin was detected during elimination, and no relevant DFPP-related side effects occurred. Reduction in tumor size > 30% occurred in 10/12 (neoadjuvant) and in 1/3 patients (recurrent). Only five grade 2 events and one grade 3 event (mucositis, neutropenia or leucopenia) and a single palmar-plantar erythrodysesthesia grade 2 were reported.

CONCLUSION

Extracorporeal elimination of PLD by DFPP is safe and efficient. CARL can diminish the main dose-limiting side effects of PLD, and probably many different DDS alike.

TRIAL REGISTRATION

DRKS00000163.

Current and emerging therapies for the treatment of myasthenia gravis

Myasthenia gravis (MG) is an autoimmmune disease in which autoantibodies to different antigens of the neuromuscular junction cause the typical weakness and fatigability. Treatment includes anticholinesterase drugs, immunosuppression, immunomodulation, and thymectomy. The autoimmune response is maintained under control by corticosteroids frequently associated with immunosuppressive drugs, with improvement in the majority of patients. In case of acute exacerbations with bulbar symptoms or repeated relapses, modulation of autoantibody activity by plasmapheresis or intravenous immunoglobulins provides rapid improvement. Recently, techniques removing only circulating immunoglobulins have been developed for the chronic management of treatment-resistant patients. The rationale for thymectomy relies on the central role of the thymus. Despite the lack of controlled studies, thymectomy is recommended as an option to improve the clinical outcome or promote complete remission. New videothoracoscopic techniques have been developed to offer the maximal surgical approach with the minimal invasiveness and hence patient tolerability. The use of biological drugs such as anti-CD20 antibodies is still limited but promising. Studies performed in the animal model of MG demonstrated that several more selective or antigen-specific approaches, ranging from mucosal tolerization to inhibition of complement activity or cellular therapy, might be feasible. Investigation of the transfer of these therapeutic approaches to the human disease will be the challenge for the future.

Guidelines on the use of therapeutic apheresis in clinical practice--evidence-based approach from the Apheresis Applications Committee of the American Society for Apheresis

The American Society for Apheresis (ASFA) Apheresis Applications Committee is charged with a review and categorization of indications for therapeutic apheresis. Beginning with the 2007 ASFA Special Issue (fourth edition), the subcommittee has incorporated systematic review and evidence-based approach in the grading and categorization of indications. This Fifth ASFA Special Issue has further improved the process of using evidence-based medicine in the recommendations by refining the category definitions and by adding a grade of recommendation based on widely accepted GRADE system. The concept of a fact sheet was introduced in the Fourth edition and is only slightly modified in this current edition. The fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis. The article consists of 59 fact sheets devoted to each disease entity currently categorized by the ASFA as category I through III. Category IV indications are also listed.

Blood compatibility and permeability of heparin-modified polysulfone as potential membrane for simultaneous hemodialysis and LDL removal

Heparin was covalently immobilized on PSf membranes to obtain a dialysis membrane with high affinity for LDL. WCA and streaming potential measurements were performed to investigate wettability and surface charge of the membranes. The morphology of the membranes was investigated by SEM. An ELISA was used to measure the adsorption and desorption of LDL on plain and modified PSf. Blood compatibility was studied by measurement of thrombin time, partial thromboplastin time, kallikrein activity and platelet adhesion. It was found that the blood compatibility of the membrane was improved by covalent immobilization of heparin at its surface. However, PSf-Hep membrane showed higher flux recovery after BSA solution filtration, which revealed antifouling property of PSf-Hep membranes.

Isoagglutinin adsorption in ABO-incompatible transplantation

As the demand for kidney transplantation is constantly growing methods to expand the donor pool have become increasingly important. ABO-incompatibility has hitherto been regarded as an absolute contraindication to living donor donation. However, as ABO-incompatibility has accounted for the majority of living donor exclusions, efforts have been made to overcome this immunologic barrier. Successful desensitization protocols thus far, have combined plasmapheresis for antibody removal with splenectomy to reduce the antibody producing B-cell pool, in addition to quadruple immunosuppression. Although good graft function has been achieved, the high risks involved have been deterrent. We have developed a protocol for ABO-incompatible kidney transplantation based on antigen-specific immunoadsorption and rituximab, in combination with standard maintenance immunosuppression (tacrolimus, mycophenolate mofetil and corticosteroids). We hypothesized that the anti-A/B antibodies could be effectively eliminated and good graft function achieved, without the complications of coagulopathy and transfusion reactions associated with plasmapheresis. Furthermore, we hypothesized that the substitution of splenectomy with a single dose of the anti-CD20 antibody rituximab would further reduce surgical risk as well as the risk of infectious complications. In 2001 the program for ABO-incompatible kidney transplantation was started at our center. To date 50 ABO-incompatible kidney transplantations have been performed according to the protocol based on antigen-specific immunoadsorption and rituximab. Safety and efficacy of the protocol has been evaluated in several studies, all showing that the antigen-specific immunoadsorption is well tolerated and without any serious side effects. Patient and graft survival as well as kidney function have been comparable to that of ABO-compatible living donor kidney transplantation and the incidence of antibody-mediated rejection 0%. We conclude that AB0-incompatible kidney transplantation using a protocol based on antigen-specific immunoadsorption and rituximab, in combination with triple immunosuppressive therapy is safe and effective. ABO-incompatibility following this protocol does not have a negative impact on graft function. ABO-incompatible kidney transplantation is equivalent to standard ABO-compatible living donor kidney transplantation.

Immobilization of heparin on polysulfone surface for selective adsorption of low-density lipoprotein (LDL)

A versatile method was developed to immobilize heparin covalently on polysulfone sheets (PSu) to achieve selective adsorption of low-density lipoprotein (LDL). This was achieved by activation of PSu with successive treatments of chlorodimethyl ether and ethylenediamine, and subsequent chemical binding of heparin with bifunctional linker molecules. A heparin density up to 0.86 microg cm(-2) on a dense PSu film was achieved. The modified PSu films were characterized by attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The hydrophilicity of the PSu film was improved greatly by covalent immobilization of heparin. The water contact angle of PSu film was decreased from 86.6 + or - 3.7 degrees to 50.5 + or - 3.2 degrees after binding of 0.36 microg cm(-2) heparin. An enzyme-linked immunosorbent assay was used to measure the binding of LDL on plain and modified PSu films. It was found that the heparin-modified PSu film could selectively recognize LDL from binary protein solutions. Furthermore, it was possible to desorb LDL from heparinized PSu, but not from plain PSu, with heparin, sodium chloride or urea solution, which indicates a selective but reversible binding of LDL to heparin. The results suggest that heparin-modified PSu membranes are promising for application in simultaneous hemodialysis and LDL apheresis therapy.

Preparation of affinity sorbents with immobilized synthetic ligands for therapeutic apheresis

Preparation and stability of a few examples of medical sorbents are described. A simple and practical technique has been developed for sorbent preparation with the low weight synthetic ligands such as amino acids, peptides or oligosaccharides. This approach to sorbent preparation enables the development of the new affine columns generation for medicine and biotechnology to be carried out with ease.

Use of therapeutic plasmapheresis in a case of canine immune-mediated hemolytic anemia

OBJECTIVE

To investigate the clinical application and potential utility of plasmapheresis in canine immune-mediated hemolytic anemia.

CASE SUMMARY

A 7-year-old spayed female Maltese diagnosed with immune-mediated hemolytic anemia was initially treated with prednisone, cyclosporine, and received multiple transfusions of packed RBC. Because of the progression of clinical signs despite traditional medical therapy, plasmapheresis was initiated. Plasma immunoglobulin G and immunoglobulin M levels were measured before, during, and after treatment to help determine if there had been a significant decrease in immunoglobulin levels with plasmapheresis. Plasmapheresis was successfully performed over a 2.5-hour period in this dog with minimal complications. Hypocalcemia was identified as a known complication of circuit anticoagulation, and was corrected through calcium supplementation. Post-plasmapheresis there was a decrease in immunoglobulin G and immunoglobulin M levels, and the patient showed clinical improvement. Following discharge the dog had no known complications of therapy, and had complete resolution of the anemia.

NEW OR UNIQUE INFORMATION PROVIDED

Plasmapheresis was performed successfully with minimal complications. Because transfusion requirements appeared to be reduced, and the procedure was well tolerated, there may be a place for this modality in severe cases to act as a bridge until medical therapy takes full effect. Because of the cost of performing this therapy, and the potential requirement for multiple treatments, it should be reserved for selected patients.

Controlled application and scheduled removal of nanoparticle based chemotherapeutics (CARL) will reduce dose limiting adverse events in anticancer chemotherapy

Clinical success of cancer chemotherapy is impaired by dose limiting toxicities. Nanoscale particle based drug delivery systems (DDS) like long circulating liposomes show improved toxicity profiles. Nevertheless, their unique pharmacokinetic properties lead to new dose limiting adverse events such as elevated skin toxicity. Though DDS accumulate in tumor tissue, only a very small fraction of the total dose reaches the target site. The overwhelming amount of a given dose is needed only to build up a diffusion gradient for effective accumulation at the target site. Due to the altered endothelial barrier, accumulation of DDS in tumor tissue is much faster than accumulation in other tissues, where dose limiting side effects occur. On the basis of these pharmakinetic data we hypothesize, that once accumulation in the tumor tissue is completed, rapid elimination of the DDS fraction still circulating in the plasma may diminish otherwise dose limiting toxicities. Rapid elimination of circulating DDS might be performed by extracorporeal apheresis treatment. Within this paper the principle of kinetic targeting by scheduled extracorporeal elimination of long circulating DDS is presented in detail. Benefits for patients are as well discussed as possible criticisms and future developments. In conclusion, the combination of DDS and scheduled apheresis may allow the development of new chemotherapy regiments with higher impact and/or less toxicity.

Granulocytapheresis in the treatment of patients with active ulcerative colitis

In recent years, considering the role of inflammatory processes and the involvement of the immune system in ulcerative colitis, granulocytapheresis, a technique for removing circulating leukocytes and preventing their migration into the intestinal mucosa, has been proposed for the treatment of acute ulcerative colitis. Initially introduced for the treatment of patients who did not respond to conventional therapy only, this new therapy may become a useful and safe method to induce clinical remission in patients with acute disease. This article will review the clinical applications and issues concerning the use of granulocytapheresis in ulcerative colitis.

Multiple organ system extracorporeal support in critically ill children

Multiple organ system extracorporeal support effectively supports brain, heart, lung, liver, kidney, coagulation, red blood cell, and immune cell function in the sickest infants and children who have multiple organ system failure. These therapies have optimum benefit if: (1) the underlying disease is reversible; (2) the therapies are performed expertly and are monitored to prevent and minimize systemic hemolysis; and (3) the therapies are provided in a goal-directed manner. These therapies represent a significant advance in pediatric critical care medicine. This article provides a framework for this multidisciplinary team approach for implementing these therapies.

A high-affinity monoclonal anti-IgE antibody for depletion of IgE and IgE-bearing cells

BACKGROUND

We have identified a monoclonal anti-human immunoglobulin E (IgE) antibody, which recognizes FcepsilonRI-bound IgE and prevents binding of IgE to FcepsilonRI. In this study, we assessed the binding kinetics and affinity of monoclonal antibody 12 (mAb12) for IgE and investigated whether mAb12 can be used for depletion of IgE and isolation of IgE-bearing cells from peripheral blood.

METHODS

Binding kinetics and affinity for IgE were studied using Biacore surface plasmon resonance technique experiments. IgE antibodies were depleted from serum using sepharose-coupled mAb12 and IgE-bearing cells were enriched from heparinized blood samples with mAb12. The extent and biological relevance of IgE depletion were studied by quantitative IgE measurements and basophil histamine release experiments. Specific binding of mAb12 to IgE-bearing cells (basophils, mast cells, IgE-secreting plasma cells) was demonstrated by FACS.

RESULTS

Monoclonal antibody 12 shows rapid association (k(a) = 5.46e5/Ms) with IgE, almost no dissociation (k(d) = 8.8e-5/s) and an affinity for IgE (K(D) = 1.61e-10 M), which is as high as that of FcepsilonRI. Immobilized mAb12 could be used to deplete IgE antibodies and isolate IgE-bearing cells from peripheral blood in a single-step procedure.

CONCLUSIONS

Monoclonal antibody 12 is a high affinity anti-human IgE antibody, which efficiently removes IgE and IgE-bearing cells from peripheral blood and may thus be used for extracorporeal depletion of IgE and IgE-bearing cells.

Elimination of liposomes by different separation principles used in low-density lipoprotein apheresis

Clinical success of many therapies is impaired by dose limiting toxicities. Nanoscale particle-based drug delivery systems such as liposomes show unique pharmacokinetic properties and improved toxicity profiles. Liposomes accumulate in tumor tissue, but only a small fraction of a total dose reaches the target site. The overwhelming amount of a given dose is needed only to build up a diffusion gradient for effective accumulation at the target site. In order to find a way to detoxify this predominant fraction after accumulation is completed, the different separation principles used for the apheresis of lipoproteins were evaluated for the extracorporeal elimination of liposomes. Appropriate radiolabeled model liposomes were prepared by extrusion. Separation efficacy, leakage of liposomal content and influence of plasma contact were measured. Membranes with pore sizes between 25 and 400 nm were used to investigate filtration properties of liposomes. Liposomes were precipitated by adding heparin and Ca(2+). Adsorption chromatography was investigated using dextran sulfate, heparin sepharose and functionalized polyacrylamide beads. Membrane filtration allowed the elimination of various liposomes, while precipitation and adsorption were only useful for positively charged liposomes. Leakage of liposomal content was not induced by adsorption, but precipitation induced leakage. Leakage during filtration was dependent on liposomal membrane lipids. Plasma contact reduced precipitation and adsorption efficacy of positively charged liposomes, while filtration properties of liposomes remained unchanged. For extracorporeal elimination of liposomal drug delivery systems, filtration-based techniques are presumably more convenient and versatile than precipitation- or adsorption-based apheresis technologies.

Drug removal by plasmapheresis: an evidence-based review

Contrary to the literature about drug removal during hemodialysis, data regarding drug removal during plasmapheresis are sparse. Over the last 40 years, approximately 70 publications-mostly case reports of overdoses-have described the effects of plasmapheresis on pharmaceutical agents. Important issues are drug extraction during plasma exchange with chemotherapy, as well as drug classes such as antiinfectives, anticoagulants, antiepileptics, cardiovascular agents, and immunosuppressants. Other considerations are the merits and pitfalls of the different methods used in published reports and recommendations for future pharmacokinetic studies in this field.

Changes in the lymphocyte subset after double-filtration plasmapheresis

To investigate the direct impact of membrane plasmapheresis on the distribution of lymphocyte subsets, paired blood specimens from 18 healthy volunteers were studied before and immediately after a single session of double-filtration plasmapheresis (DFP). After a single session of DFP treatment, the number of helper T cells had increased by 2.34% (P = .0142), whereas the suppressor T cells decreased by 2.22% (P = .0095), with consequent increases in the T-helper/T-suppressor (Th/Ts) ratio (P < .0001). The number of B cells was also significantly increased (P = .0012) after DFP treatment; however, total T and natural killer cells did not differ after treatment. Older volunteers ( > 40 years) had significantly higher percentages of B (P = .0002) and helper T (P = .0432) cells after treatment. In contrast, younger subjects had a lower percentage of suppressor T cells (P = .0174). However, the Th/Ts ratio increased significantly irrespective of age group (P = .0016) and sex (P = .0016). A single session of membrane plasmapheresis seemed to activate the cellular immune system in our sample of 18 healthy volunteers, increasing the number of B cells and the Th/Ts ratio.

Advances in apheresis therapy for glomerular diseases

This article is an overview of the immunomodulatory effects of apheresis in renal diseases, especially primary and secondary glomerulonephritis, and the clinical evidence for the efficacy of apheresis therapy. Permeability factor(s) derived from circulating T cells are speculated to have a crucial role in the proteinuria of nephrotic syndrome (NS). Plasma exchange (PE); immunoadsorption plasmapheresis (IAPP), using protein A sepharose cartridges; low-density lipoprotein apheresis; and lymphocytapheresis (LCAP) have been used to remove such factors or pathogenic T cells. Other glomerular diseases induced by specific antibodies such as anti-glomerular basement membrane antibodies, anti-neutrophil cytoplasmic antibodies, and immune-complexes have also been treated with PE, double-filtration plasmapheresis, IAPP, and LCAP. Recommendations, based on the evidence from recent randomized controlled studies, have been established in apheresis therapy for various glomerular diseases.

Guidelines on the use of therapeutic apheresis in clinical practice—Evidence-based approach from the apheresis applications committee of the American society for apheresis

The American Society for Apheresis (ASFA) Apheresis Applications Committee is charged with a review and categorization of indications for therapeutic apheresis. This elaborate process had been undertaken every 7 years resulting in three prior publications in 1986, 1993, and 2000 of "The ASFA Special Issues." This article is the integral part of the Fourth ASFA Special Issue. The Fourth ASFA Special Issue is significantly modified in comparison to the previous editions. A new concept of a fact sheet has been introduced. The fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis. A detailed description of the fact sheet is provided. The article consists of 53 fact sheets devoted to each disease entity currently categorized by the ASFA. Categories I, II, and III are defined as previously in the Third Special Issue. However, a few new therapeutic apheresis modalities, not yet approved in the United States or are currently in clinical trials, have been assigned category P (pending) by the ASFA Clinical Categories Subcommittee. The diseases assigned to category IV are discussed in a separate article in this issue.

Plasma exchange in the management of high risk pregnant patients with primary antiphospholipid syndrome. A report of 9 cases and a review of the literature

A second-line treatment protocol including plasma exchange (PE) in addition to the standard therapies was scheduled and utilized in our hospital with the intent of improving the outcome of high risk pregnancies of women with primary antiphospholipid syndrome (APS). This paper chronologically reports and discusses the results obtained in these patients over a 15-year period. Between April 1991 and September 2006, 142 pregnancies of patients with APS were followed by us. Nine of these (6.3%), who did not respond to the conventional procedures or showed complications during the treatments were shifted to a PE protocol management. All these women had a history of previous thromboembolism associated to triple antiphospholipid antibody positivity. Nine pregnancies of 7 patients (2 women were treated twice) were thus followed using PE therapy, which has undergone modification over the years. In the cases studied the outcome of pregnancy varied according to the different PE therapy conditions. This study suggests that prophylactic PE treatment administered along with full anticoagulation and IVIG therapy could be a valuable therapeutic option in high risk pregnant APS women. Further studies in this type of patients are certainly warranted.

Update in the treatment of paediatric ulcerative colitis

Ulcerative colitis is an important disease in the paediatric population. Ulcerative colitis is one of the chronic inflammatory bowel diseases, and is medically incurable. However, the arsenal of medications has grown as knowledge of the pathogenesis of this disease advances. This review looks at the classical treatments for children with ulcerative colitis, including the 5-aminosalicylates, corticosteroids and imunomodulators, as well as biological therapy and other, newer modalities.

Direct Adsorption of Low-Density Lipoprotein by DALI-LDL-Apheresis: Results of a Prospective Long-term Multicenter Follow-up Covering 12 291 Sessions

Direct adsorption of lipoproteins (DALI) is the first low density lipoprotein (LDL)-apheresis technology by which atherogenic LDL and lipoprotein(a) (Lp(a)) can be selectively removed from whole blood without plasma separation. The present follow-up was carried out to evaluate the clinical efficacy, selectivity and safety of long-term DALI apheresis. The follow-up was carried out in an open, prospective uncontrolled multicenter clinical design. Included were 158 drug-resistant hypercholesterolemic patients from 28 apheresis centers. These patients underwent 12 291 DALI sessions between January 1997 and March 2002. The patients suffered from severe atherosclerosis and their mean LDL-C was 188 mg/dL before the sessions. Mean follow-up was 25 +/- 16 (range 1-56) months during which 78 +/- 53 sessions were carried out. In most treatments, DALI 750 (63%) or DALI 1000 (30%) adsorbers were used. On average, 7423 +/- 1495 mL blood was processed at a flow rate of 84 +/- 16 mL/min in 102 +/- 25 min. Acute reductions by the single DALI sessions averaged 69 +/- 12% for LDL-C, 41 +/- 18% for TG, 15 +/- 10% for HDL-C, 19 +/- 11% for fibrinogen and 62 +/- 24% for Lp(a) (in patients with Lp(a) > 30 mg/dL). Adverse events were recorded in only 3.9% of the sessions. In this 5-year follow-up, long-term therapy with DALI was safe, effective and selective as LDL-C and Lp(a) could be reduced by >60% per session in approximately 100 min treatment time while HDL-C decrease and the incidence of AE were low.