Plasma concentrations and pharmacokinetics of dimethylsulfoxide and its metabolites in patients undergoing peripheral-blood stem-cell transplants

Comparison of cryoprotectants in hematopoietic cell infusion-related adverse events

BACKGROUND

The standard cryoprotectant for human cellular products is dimethyl sulfoxide (DMSO), which is associated with hematopoietic cell infusion-related adverse events (HCI-AEs) in hematopoietic stem cell transplantation including peripheral blood stem cell (PBSC) transplantation (PBSCT). DMSO is often used with hydroxyethyl starch (HES), which reduces DMSO concentration while maintaining the postthaw cell recovery. The cryoprotectant medium CP-1 (Kyokuto Pharmaceutical Industrial) is widely used in Japan. After mixture of a product with CP-1, DMSO and HES concentrations are 5% and 6%, respectively. However, the safety profile of CP-1 in association with HCI-AEs has not been investigated.

STUDY DESIGN AND METHODS

To compare CP-1 with other cryoprotectants, we conducted a subgroup analysis of PBSCT recipients in a prospective surveillance study for HCI-AEs. Moreover, we validated the toxicity of CP-1 in 90 rats following various dose administration.

RESULTS

The PBSC products cryopreserved with CP-1 (CP-1 group) and those with other cryoprotectants, mainly 10% DMSO (non-CP-1 group), were infused into 418 and 58 recipients, respectively. The rate of ≥grade 2 HCI-AEs was higher in the CP-1 group, but that of overall or ≥grade 3 HCI-AEs was not significantly different, compared to the non-CP-1 group. Similarly, after propensity score matching, ≥grade 2 HCI-AEs were more frequent in the CP-1 group, but the ≥grade 3 HCI-AE rate did not differ significantly between the groups. No significant toxicity was detected regardless of the CP-1 dose in the 90 rats.

CONCLUSIONS

Infusion of a CP-1-containing PBSC product is feasible with the respect of HCI-AEs.

Automated thawing increases recovery of colony-forming units from banked cord blood unit grafts

BACKGROUND

The cell dose infused for cord blood transplantation strongly correlates with outcomes following transplantation. Post thaw recoveries can be improved by washing cord blood units (CBUs) in dextran/albumin. Early methods used a labor-intensive manual process. We have recently developed and validated an automated washing method. We now report our results of a study comparing cellular recoveries achieved after manual and automated wash, as well as the impact on engraftment following allogeneic transplantation.

STUDY DESIGN AND METHODS

CBUs distributed by the Carolinas Cord Blood Bank for clinical use at Duke University after manual or automated wash were included in this report. Precryopreservation total nucleated cell count, total CD34+, colony-forming units, recoveries, and sterility were analyzed by wash method. Patient age, cell dose/weight, diagnosis, conditioning regimen, immunosuppression, and time to neutrophil engraftment were also analyzed.

RESULTS

Manual and automated washed CBUs yielded similar total nucleated cell count and total CD34+ recoveries. Significantly higher colony-forming units recoveries were achieved after automated washing. Patients who received CBUs washed via an automated method experienced earlier neutrophil engraftment.

CONCLUSION

While manual and automated washing achieved similar post thaw cellular recoveries, automated washed CBUs demonstrated higher colony-forming unit recovery, which is an important predictor of potency and engraftment. Furthermore, we demonstrated that automated washing was associated with earlier neutrophil engraftment. Our findings favor the use of an automated wash method over a manual approach.

CD4+ T cell activation, function, and metabolism are inhibited by low concentrations of DMSO

Dimethyl sulfoxide (DMSO) is a polar organic solvent used in a wide range of biological applications. DMSO is routinely used as a cryoprotectant for long-term cell freezing as well as to dissolve peptides and drugs for immune cell functional assays. Here, human CD4⁺ T cell activation, cytokine production, proliferation, and metabolism were investigated after stimulation in the presence of 0.01% to 1%, DMSO, representing concentrations commonly used in vitro. Surface expression of the activation markers CD69, CD25 and CD154 after polyclonal activation of CD4⁺ T cells was inhibited by 0.25% or higher concentrations of DMSO. The frequencies of IL-21⁺, IL-4⁺, and IL-22⁺ CD4⁺ T cells, following polyclonal activation were variably inhibited by DMSO at concentrations ranging from 0.25% to 1%, whereas IFNγ⁺ cells were unaffected. CD4⁺ T cell proliferation after anti-CD3 or antigen stimulation was inhibited by 0.5% DMSO and abolished by 1% DMSO. After polyclonal stimulation, glucose uptake was inhibited in the presence of 1% DMSO, but only minor effects on CD4⁺ T cell respiration were observed. Consistent with the immune effects, the gene expression of early signaling and activation pathways were inhibited in CD4⁺ T cells in the presence of 1% DMSO. Our study revealed that DMSO at concentrations generally used for in vitro studies of T cells impacts multiple features of T cell function. Therefore, we urge care when adding DMSO-containing preparations to T cell cultures.

Toxic effects of dimethyl sulfoxide on red blood cells, platelets, and vascular endothelial cells in vitro

Dimethyl sulfoxide (DMSO) is widely used in biological studies as a cryoprotective agent for cells and tissues, and also for cryopreserved platelets (PLTs). However, few data on the toxic effects of DMSO following intravenous infusion of cryopreserved PLTs are available. The aim of this study was to explore dose-related effects of DMSO on red blood cells (RBCs), PLTs and vascular endothelial cells in vitro. The results showed that DMSO treatments had significant effects on RBCs, affecting osmotic fragility and increasing hemolysis. Free hemoglobin (FHb) level of RBCs was 0.64 ± 0.19 g L^-1 after incubation for 6 h with 0.6% DMSO, and these levels were elevated compared with controls (0.09 ± 0.05 g L^-1). Aggregation of PLTs induced by adenosine diphosphate, thrombin (THR), and thrombin receptor activator peptide (TRAP) were inhibited by DMSO treatment because the THR generation capacity was reduced. The intensity of the cytosolic esterase-induced fluorescence response from carboxy dimethyl fluorescein diacetate (CMFDA) in PLTs was decreased about 29% ± 0.04% after treatment with DMSO. DMSO also inhibited the proliferation of the vascular endothelial cell line EAhy926 cells by blocking the G1 phase. Apoptosis of EAhy926 cells with 0.6% DMSO stimulation was increased threefold compared to controls. On the basis of these findings, it was concluded that DMSO was toxic to the hematologic system. This should be taken into account when assessing the infusion effects of cryopreserved PLTs or other blood products requiring DMSO as a vehicle, such as cryopreserved stem cells, in order to avoid adverse therapeutic effects.

Topical Nonsteroidal Anti-Inflammatory Drugs: The Importance of Drug, Delivery, and Therapeutic Outcome

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used in the treatment of pain associated with a variety of indications, including arthritic conditions, but their usefulness is often limited by dose-dependent adverse events (AEs), such as gastrointestinal disturbances, cardiovascular events, and renal toxicity. The risk of such effects could be reduced by the use of topical formulations, which offer the potential to deliver analgesic concentrations locally, at the site of inflammation, while minimizing systemic concentrations. The topical preparations currently approved in the United States are diclofenac sodium 1.5% topical solution (containing dimethyl sulfoxide as a penetration enhancer), diclofenac sodium gel 1%, and a diclofenac hydroxyethylpyrrolidine 1.3% patch. Each of these topical NSAIDs provide drug delivery to subcutaneous tissues for the management of pain associated with osteoarthritis or soft-tissue injuries. Furthermore, these formulations are not significantly associated with the systemic AEs associated with oral NSAIDs; the most common AEs associated with topical formulations are local skin reactions, which are usually mild and self-limiting. Other topical NSAID preparations approved in the European Union include ibuprofen creams and gels, ketoprofen gel, felbinac gel and cutaneous foam, and piroxicam gel. Meta-analyses have confirmed the efficacy and safety of these preparations. However, it is important to recognize that pharmacokinetic absorption from topical formulations can vary markedly, even between different formulations of the same drug, depending on the agent, the underlying disorder, and the site of application. It is therefore essential to consider the patient, the drug, and the drug delivery mechanism when selecting a topical NSAID preparation.

Current thawing and infusion practice of cryopreserved cord blood: the impact on graft quality, recipient safety, and transplantation outcomes

Methods of handling, thawing, and infusion of cord blood (CB) products vary substantially among thaw/transplant centers (TCs). This review 1) compares currently available CB product types and thaw methods recommended by CB banks (CBBs), 2) discusses causes of inconsistency in thaw method application at TCs, 3) advises elements to consider in thaw method approval or selection at the TC, 4) provides a procedural template for the traditional thaw methods, and 5) suggests acceptable time from product thaw to infusion and other considerations for safe infusion. It also compares postinfusion adverse reaction and engraftment data as functions of thaw methods. Remarks and suggestions made throughout this review are: 1) not intended to supersede manufacturer's instructions but meant to support the standardization of preparative procedures recommended by CBBs and 2) intended to help TCs to investigate relevant quality issues and handle challenges, especially when the TC is unable to follow recommendations due to foreseeable technical, quality, and/or clinical factors.

Dimethyl sulfoxide (DMSO) attenuates the inflammatory response in the in vitro intestinal Caco-2 cell model

This study aimed to investigate dose effects of dimethyl sulfoxide (DMSO) (0.05-1%) on the intestinal inflammatory response in confluent- and differentiated-Caco-2 cells stimulated with interleukin (IL)-1β or a pro-inflammatory cocktail for 24 h. Cyclooxygenase-2 (COX-2) activity was assayed by incubating inflamed cells with arachidonic acid and then measuring prostaglandin-E(2) (PGE(2)) produced. Soluble mediators (IL-8, IL-6, macrophage chemoattractant protein-1 (MCP-1), and COX-2-derived PGE(2)) were quantified by enzyme immunoassays and mRNA expression of 33 proteins by high throughput TaqMan Low Density Array. Data showed that DMSO decreased induced IL-6 and MCP-1 secretions in a dose-dependent manner (P<0.05), but not IL-8; these effects were cell development- and stimulus- independent. Moreover, in IL-1β-stimulated confluent-cells, DMSO dose-dependently reduced COX-2-derived PGE(2) (P<0.05). DMSO at 0.5% decreased significantly mRNA levels of 14 proteins involved in the inflammatory response (including IL-6, IL-1α, IL-1β, and COX-2). Thus, DMSO at low concentrations (0.1-0.5%) exhibits anti-inflammatory properties in the in vitro intestinal Caco-2 cell model. This point is important to be taken into account when assessing anti-inflammatory properties of bioactive compounds requiring DMSO as vehicle, such as phenolic compounds, in order to avoid miss-interpretation of the results.

DMSO inhibits human platelet activation through cyclooxygenase-1 inhibition. A novel agent for drug eluting stents?

BACKGROUND

DMSO is routinely infused together with hematopoietic cells in patients undergoing myeloablative therapy and was recently found to inhibit smooth muscle cells proliferation and arterial thrombus formation in the mouse by preventing tissue factor (TF), a key activator of the coagulation cascade. This study was designed to investigate whether DMSO prevents platelet activation and thus, whether it may represent an interesting agent to be used on drug eluting stents.

METHODS AND RESULTS

Human venous blood from healthy volunteers was collected in citrated tubes and platelet activation was studied by cone and platelet analyzer (CPA) and rapid-platelet-function-assay (RPFA). CPA analysis showed that DMSO-treated platelets exhibit a lower adherence in response to shear stress (-15.54+/-0.9427%, n=5, P<0.0001 versus control). Additionally, aggregometry studies revealed that DMSO-treated, arachidonate-stimulated platelets had an increased lag phase (18.0%+/-4.031, n=9, P=0.0004 versus control) as well as a decreased maximal aggregation (-6.388+/-2.212%, n=6, P=0.0162 versus control). Inhibitory action of DMSO could be rescued by exogenous thromboxane A2 and was mediated, at least in part, by COX-1 inhibition.

CONCLUSIONS

Clinically relevant concentrations of DMSO impair platelet activation by a thromboxane A2-dependent, COX-1-mediated effect. This finding may be crucial for the previously reported anti-thrombotic property displayed by DMSO. Our findings support a role for DMSO as a novel drug to prevent not only proliferation, but also thrombotic complications of drug eluting stents.

Dimethyl Sulfoxide Inhibits Tissue Factor Expression, Thrombus Formation, and Vascular Smooth Muscle Cell Activation

Background— Subacute stent thrombosis is a major clinical concern, and the search for new molecules to cover stents remains important. Dimethyl sulfoxide (DMSO) is used for preservation of hematopoietic progenitor cells and is infused into patients undergoing bone marrow transplantation. Despite its intravenous application, the impact of DMSO on vascular cells has not been assessed.

Methods and Results— In human endothelial cells, monocytes, and vascular smooth muscle cells (VSMC), DMSO inhibited tissue factor (TF) expression and activity in response to tumor necrosis factor-α or thrombin in a concentration-dependent manner. DMSO did not exert any toxic effects as assessed by phase-contrast microscopy, trypan blue exclusion, and lactate dehydrogenase release. Real-time polymerase chain reaction revealed that inhibition of TF expression occurred at the mRNA level. This effect was mediated by reduced activation of the mitogen-activated protein kinases c-Jun terminal NH 2 kinase (51±6%; P =0.0005) and p38 (50±3%; P <0.0001) but not p44/42 ( P =NS). In contrast to TF, DMSO did not affect expression of TF pathway inhibitor or plasminogen activator inhibitor-1. In vivo, DMSO treatment suppressed TF activity (41%; P <0.002) and prevented thrombotic occlusion in a mouse carotid artery photochemical injury model. DMSO also inhibited VSMC proliferation (70%; P =0.005) and migration (77%; P =0.0001) in a concentration-dependent manner; moreover, it prevented rapamycin and paclitaxel-induced upregulation of TF expression.

Conclusions— DMSO suppresses TF expression and activity, as well as thrombus formation; in addition, it inhibits VSMC proliferation and migration. Given its routine use in modern clinical practice, we propose DMSO as a novel strategy for coating drug-eluting stents and treating acute coronary syndromes.

Multidisciplinary utilization of dimethyl sulfoxide: pharmacological, cellular, and molecular aspects

DMSO is an amphipathic molecule with a highly polar domain and two apolar methyl groups, making it soluble in both aqueous and organic media. It is one of the most common solvents for the in vivo administration of several water-insoluble substances. Despite being frequently used as a solvent in biological studies and as a vehicle for drug therapy, the side-effects of DMSO (undesirable for these purposes) are apparent from its utilization in the laboratory (both in vivo and in vitro) and in clinical settings. DMSO is a hydrogen-bound disrupter, cell-differentiating agent, hydroxyl radical scavenger, intercellular electrical uncoupler, intracellular low-density lipoprotein-derived cholesterol mobilizing agent, cryoprotectant, solubilizing agent used in sample preparation for electron microscopy, antidote to the extravasation of vesicant anticancer agents, and topical analgesic. Additionally, it is used in the treatment of brain edema, amyloidosis, interstitial cystitis, and schizophrenia. Several systemic side-effects from the use of DMSO have been reported, namely nausea, vomiting, diarrhea, hemolysis, rashes, renal failure, hypertension, bradycardia, heart block, pulmonary edema, cardiac arrest, and bronchospasm. Looking at the multitude of effects of DMSO brought to light by these studies, it is easily understood how many researchers working with DMSO (or studying one of its specific effects) might not be fully aware of the experiences of other groups who are working with it but in a different context.

Toxicity to topical dimethyl sulfoxide (DMSO) when used as an extravasation antidote

DMSO is a dipolar, aprotic, hygroscopic solvent for which a large number of pharmacologic properties have been claimed. Topical DMSO is considered an effective and safe antidote to be used with topical cooling after extravasations of vesicant drugs. A case of toxicity after its use as an antidote is described. Furthermore, the increasing importance of DMSO pharmacology, as its use in haematologic patients is spreading, is reviewed.

Intravenous busulphan for conditioning before autologous or allogeneic human blood stem cell transplantation

This study was undertaken to evaluate the toxicity and pharmacokinetics of a dimethyl sulphoxide (DMSO)-based intravenous formulation of busulphan in the conditioning of 45 patients undergoing allogeneic or autologous stem cell transplantation (SCT). Busulphan was given as a single daily dose. In 15 patients a single dose of intravenous busulphan, given over 3 h in 1 d, was combined with additional oral (single daily) doses. Thirty patients received all four daily doses intravenously. Busulphan plasma levels were analysed using high performance liquid chromatography. There was no major acute toxicity with daily intravenous doses of 2.8-3.1 mg/kg infused over 3 h. No veno-occlusive disease (VOD) was seen in 30 patients receiving busulphan as an intravenous formulation over 4 d. In the group of 15 patients receiving three oral doses and one intravenous single daily dose, one patient experienced mild VOD. Pharmacokinetic samples were taken over at least 2 d of treatment in 44 patients. The area under the concentration time curve (AUC) values normalized for a dose of 1 mg/kg were 7000 ng/ml x h on d 1 and 5890 ng/ml x h on d 4, thus showing a moderate decrease over time. This was accompanied by a moderate increase of the clearance from 2.6 to 3.0 ml/min/kg. Administration of busulphan as a DMSO-based intravenous formulation was well tolerated. The total dose of busulphan can be given in four (rather than the typical 16) doses. With such a regimen, the intravenous administration becomes feasible on an outpatient basis.

Differentiation therapy of human cancer: basic science and clinical applications

Current cancer therapies are highly toxic and often nonspecific. A potentially less toxic approach to treating this prevalent disease employs agents that modify cancer cell differentiation, termed 'differentiation therapy.' This approach is based on the tacit assumption that many neoplastic cell types exhibit reversible defects in differentiation, which upon appropriate treatment, results in tumor reprogramming and a concomitant loss in proliferative capacity and induction of terminal differentiation or apoptosis (programmed cell death). Laboratory studies that focus on elucidating mechanisms of action are demonstrating the effectiveness of 'differentiation therapy,' which is now beginning to show translational promise in the clinical setting.

Reversible leukoencephalopathy associated with re-infusion of DMSO preserved stem cells

We report a case of posterior reversible leuko- encephalopathy (PRL) following the infusion of dimethylsulfoxide (DMSO) cryopreserved autologous stem cells in the setting of myeloablative chemotherapy in a patient with recurrent Ewing's sarcoma. Magnetic resonance (MR) imaging revealed white matter changes which resolved over the next 2 months. Bone Marrow Transplantation (2000) 26, 797-800.

Severe respiratory depression after dimethylsulphoxide-containing autologous stem cell infusion in a patient with AL amyloidosis

Adverse reactions with DMSO-cryopreserved stem cell infusion are well-recognized. However, severe, life-threatening anaphylactic reactions with DMSO are very rarely described in the literature. We report here a 58-year-old female with AL amyloidosis who developed an unexpected episode of respiratory arrest a few seconds after the beginning of thawed stem cell product infusion. Fortunately, the patient was resuscitated successfully without the need for intubation. The prompt development of the reaction just a few seconds after the stem cell infusion convincingly implicates DMSO as the potential suspect. The presence of amyloid cardiomyopathy might have also contributed to this adverse event. Bone Marrow Transplantation (2000) 25, 1299-1301.

Quantification of residual dimethyl sulfoxide in supernatants of haematopoietic stem cells by capillary zone electrophoresis

Dimethyl sulfoxide (DMSO) is a chemical compound that is used to preserve haematopoietic stem cells during freezing at -180 degrees C. As DMSO is largely removed by washing before reinjection of cells into a patient, accidents (notably cardiovascular) are infrequent. The lack of a method for evaluating the residual quantities of this product led us to develop a technique for assaying DMSO by capillary zone electrophoresis without extraction. This simple, rapid and precise technique was applied to the supernatant of cell pellets of thirteen patients before and after washing.