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Robert Weinstein

Publications and source records attributed to Robert Weinstein.

14 recordsLinked to original sources
PubMed2007

Rituximab treatment in patients with IVIg-dependent immune polyneuropathy: a prospective pilot trial.

We studied the effect of rituximab in allowing a reduction in dose of intravenous immune globulin (IVIg) in six patients with IVIg-dependent, relapsing immune polyneuropathy. Rituximab (375 mg/m(2) intravenously each week for 4 weeks) was administered in a prospective, open-label design to two patients with chronic inflammatory demyelinating polyneuropathy (CIDP), two with multifocal motor neuropathy (MMN), one with neuropathy and anti-myelin-associated glycoprotein (MAG) antibody neuropathy, and one with Sjögren syndrome (SS) ataxic neuropathy. The primary endpoint was a reduced cumulative IVIg dosage by at least 25% at 1 year after rituximab therapy compared to the previous year. Secondary endpoints included an improved summed strength score by at least 5 points on the Medical Research Council scale, an increased sensory score by at least 4 points, or an improved Rankin disability score by at least 1 grade. Total IVIg dosage decreased by greater than 25% in one patient with SS neuropathy and one with MMN; the dosage was unchanged in one with CIDP, slightly reduced in the patient with anti-MAG neuropathy, and increased in one with CIDP and another with MMN. There was no improvement in secondary endpoints. No adverse events occurred. In this small prospective study, rituximab did not reduce IVIg requirements in the majority of patients with IVIg-dependent, immune-mediated polyneuropathies.

Antibodies, Monoclonal↗
PubMed2006

Therapeutic plasma exchange performed in tandem with hemodialysis for patients with M-protein disorders.

M-proteins are monoclonal immunoglobulins or immunoglobulin fragments that aberrantly accumulate in the plasma. Hemodialysis (HD) patients with M-proteins may, under certain circumstances, also need therapeutic plasma exchange (TPE). We employed a protocol for tandem TPE/HD in patients with M-protein disorders. We followed the urea reduction ratio (URR), a measure of the efficiency of HD, to compare the effect of TPE on HD efficiency during tandem procedures versus the efficiency of HD performed as a stand-alone procedure in the same patients. Three men (J.M., R.T., M.M.) underwent 23, 80, and 25 tandem TPE/HD over 3, 17, and 7 months, respectively, almost all in the outpatient setting. Mean whole blood flow rate (in ml/min) was slower during hemodialysis alone than during TPE/HD for J.M. (289 +/- 24 vs. 332 +/- 22, P < 0.0001) and R.T. (310 +/- 20 vs. 367 +/- 15, P < 0.0001) but not for M.M. (395 +/- 65 vs. 404 +/- 62, P = 0.6844). URR was equivalent during hemodialysis alone and during TPE/HD for J.M. (54 +/- 4.2 vs. 58 +/- 1.4, P = 0.3333), R.T. (69 +/- 4.9 vs. 70 +/- 2.5, P = 0.9804), and M.M. (71 +/- 2.4 vs. 67 +/- 1.5, P = 0.1143). J.M.'s renal function recovered sufficiently to permit discontinuation of hemodialysis. R.T. experienced both subjective and objective improvement of his arthritic symptoms. M.M. achieved hemostatic control but ultimately died of amyloidosis. TPE/HD is feasible using disparate pieces of equipment when the therapeutic plasma exchange circuit is connected in parallel with the low-pressure side of the hemodialysis circuit. Our experience illustrates that therapeutic plasma exchange did not adversely impact hemodialysis when the two procedures were performed in tandem.

Adult↗
PubMed2006

The acute phase reactant, fibrinogen, as a guide to plasma exchange therapy for acute Guillain-Barré syndrome.

The Guillian Barré syndrome is an acute inflammatory disorder for which plasma exchange is effective treatment. Up to 10% relapse after plasma exchange suggesting that treatment sometimes finishes before disease activity has resolved. We studied whether plasma fibrinogen, an inflammatory marker, might be used to determine when to discontinue plasma exchange in patients with acute Guillain-Barré syndrome. We conducted a post-hoc analysis of apheresis database and hospital records of patients treated with plasma exchange for acute Guillain-Barré syndrome during 1999-2004. Data were analyzed from 28 patients who underwent a total of 29 courses of plasma exchange for acute Guillain-Barré syndrome. The mean (+/-SD) plasma fibrinogen concentration was 422.5 (+/-96.4) mg/dl at the time of presentation and, in 17 of the 29, it was above 400 mg/dl (reference range 200-400). Twenty of the 21 patients whose fibrinogen fell by more than 30% from baseline by the time of the final plasma exchange treatment had neurological improvement. There was improvement in only 3 of the 8 instances where fibrinogen decreased by less than 30% by the end of plasma exchange therapy. A > or =30% decrease in fibrinogen by the conclusion of plasma exchange was significantly associated with sustained neurological improvement (P = 0.0025). The plasma fibrinogen level appears to reflect disease activity in acute Guillain-Barré syndrome. A <30% fall in fibrinogen level despite plasma exchange may indicate the need to continue plasma exchange to maximize the benefit of treatment or minimize the risk of relapse. Therapeutic plasma exchange need not be extended when plasma fibrinogen remains > or =30% below its level at presentation by the time of the final planned plasma exchange procedure.

Acute Disease↗
PubMed2006

Safety and efficacy of peripheral blood progenitor cell mobilization and collection in patients with advanced coronary heart disease.

Information on the safety of mobilization and collection of peripheral blood progenitor cells (PBPC) in patients with advanced coronary heart disease (CHD) is limited. We report herein our early experience with patients participating in a Phase I trial of injection of autologous CD 34(+) cells into threatened, ischemic myocardium for neovascularization and symptom relief in patients with chronic refractory myocardial ischemia. All patients had advanced inoperable CHD despite the best medical therapy. Granulocyte colony stimulating factor (G-CSF, 5 microg/kg/day) was administered subcutaneously for 5 days for mobilization of CD34(+) cells into the peripheral blood. PBPCs were collected in the outpatient apheresis suite on day 5. Nine patients from our institution were evaluable. Adverse effects of mobilization included: increase in frequency and/or intensity of angina in 8 patients (88.8%); bone pain in 7 patients (77.7%); headaches in 4 patients (44.4%); 2 patients (22%) were hospitalized. Collection phase toxicities included: tingling in 5 patients (55.5%) and angina in 3 patients (33%). All procedures were completed without new myocardial infarction, congestive heart failure, or death. The median peripheral blood CD34(+) cell count on day 5 of G-CSF was 21 cells/microl (range 10-40 cells/microl). A median of 1.65 x 10(6) CD34(+) cells/kg (range: 0.13-3.0 x 10(6)/kg) were harvested. We conclude that mobilization and collection of PBPC in patients with advanced CHD can be safely performed as an outpatient procedure. Apheresis professionals should be aware of the intensity and frequency of angina in this patient population.

Aged↗
PubMed2005

The new apheresis and blood and marrow transplantation-related current procedural terminology codes for payment of apheresis and blood and marrow transplantation services.

To address deficiencies in Current Procedural Terminology (CPT) codes that describe many of the clinical services offered to patients, several physicians in the blood and marrow transplantation and apheresis field joined with a coalition including the American Society of Hematology, American Society for Blood and Marrow Transplantation, American Association of Blood Banks, American Society of Clinical Oncology, American Society for Apheresis, National Marrow Donor Program, and American Red Cross to collaborate in addressing these deficiencies by designing new CPT codes. The CPT editorial panel approved 18 new or revised codes. All these codes were given permanent or temporary value by the relative value unit update committee, but not all values were approved by the Centers for Medicare & Medicaid Services (CMS), in particular, the cell-processing codes and the unrelated donor search code. Further discussions addressing these concerns are under way with the CMS. Use of these new codes allows apheresis and transplant centers to charge appropriately for these services. This will help transplant center contracts with CPT codes, with payers more specifically describing services offered to these patients. In turn, this will give better justification for payment. This may allow certain payments for services to increase and help transplant centers better allocate revenue from fixed global case rate payments. Details about the individual codes and their approval process are reviewed in this article.

Blood Component Removal↗
PubMed2004

Long-term therapeutic plasma exchange in the outpatient setting using an implantable central venous access device.

We presented the results of our prospective trial of the Bard CathLink 20 in outpatient therapeutic plasma exchange in May 2000. Since the close of that study, three of the original subjects and one additional subject have received continuous outpatient treatment using the device. We report herein on its long-term use. Four patients with demyelinating polyneuropathy underwent outpatient plasma exchange of 1-1 1/4 plasma volumes using Bard CathLink 20 venous access devices for up to 2 1/2 years. Treatment schedules varied according to the status of the patient's neuropathy. Four men (age 59, 60, 76, 79) underwent 55, 56, 38, and 41 plasma exchanges over 18.5, 18, 20, and 38.5 months, respectively, all in the outpatient setting. Ninety-one percent were completed in <150 min (mean 120 +/- 28 min) with 3,783 +/- 314 ml of plasma removed. Mean access flow rates were approximately 70 +/- 11 ml/min. Plasma flow rates were approximately 38 +/- 6 ml/min. (During our original 6-month prospective trial, access and plasma flow rates were approximately 54 and 32 ml/min, respectively). There were no adverse effects resulting from use of the CathLink and no hospitalizations were needed for plasma exchange. Pressure alarms were infrequent. Access and plasma flow rates achieved with the CathLink 20 have increased by about 30 and 16%, respectively, with long-term use. The conclusion from our prospective trial of this device, that it could conveniently be used for long-term outpatient plasma exchange, is supported by our follow-up experience.

Aged↗
PubMed2003

External fixators for elective rearfoot and ankle arthrodesis. Techniques and indications.

Since its introduction to the western hemisphere in the mid 1980's, Gavriel Ilizarov's ring fixator system has been studied extensively and shown to be a superior mechanical construct for stabilizing limb segments. This newfound form of external fixation has radically changed many elements of foot and ankle reconstruction, providing a modular device that can accommodate the complex limb deformities while performing multiple tasks. This article summarizes the authors' experience with compression arthrodesis of the rearfoot and ankle using external fixation.

Ankle Joint↗
PubMed2003

Use of recombinant human antithrombin in patients with congenital antithrombin deficiency undergoing surgical procedures.

BACKGROUND: Hereditary antithrombin (AT) deficiency is associated with a significant risk of venous thromboembolism. Patients with this disorder frequently require long-term anticoagulation. Discontinuation of anticoagulation for childbirth or surgery may carry a substantial thrombotic risk. For this reason, replacement with AT concentrate has been used when anticoagulation is interrupted. A new recombinant human AT concentrate, produced using transgenic technology, has recently been developed. STUDY DESIGN AND METHODS: Human recombinant AT (rhAT) was provided by GTC Biotherapeutics, Inc. on a compassionate-use basis for five patients with hereditary AT deficiency who underwent six surgical procedures. Patients were treated perioperatively. Dosing was determined individually by the investigators with a goal of maintaining an AT activity of 80 to 150 percent. RESULTS: There was no clinical evidence of thrombosis or bleeding. Four of the five patients had postoperative duplex ultrasound studies of the lower extremities, which showed no evidence of acute thrombosis. Four patients were tested for antirecombinant rhAT antibodies postoperatively and were negative. CONCLUSION: These case reports indicate that rhAT can provide effective support for AT-deficient patients who undergo surgery. Further study of this product is needed to define optimal dosing and further assess clinical response.

Adult↗
PubMed2002

Efficacy of intravenous immunoglobulin in patients with IgG monoclonal gammopathy and polyneuropathy.

CONTEXT: The optimal treatment of patients with neuropathy associated with IgG monoclonal gammopathy of undetermined significance is unknown. Plasma exchange has been shown to be effective but alternative therapies have not been systematically evaluated. OBJECTIVE: To report our experience with intravenous immunoglobulin (IVIG) in patients with IgG monoclonal gammopathy of undetermined significance polyneuropathy. DESIGN: Retrospective review of clinical and electrodiagnostic features of 20 consecutive patients treated with IVIG over an 8-year period. SETTING: Academic medical center. MAIN OUTCOME MEASURES: Medical Research Council strength (maximum, 40 points) and sensory (maximum, 26 points) scores, modified Rankin Disability Scale score. RESULTS: There were 14 men and 6 women (mean age, 65 years; age range, 36-82 years). The mean strength score was 35.6 points and the mean sensory score was 15.8 points prior to therapy. After IVIG therapy, the mean strength score increased by 1.1 points (P =.22) and the sensory score increased by 1.7 points (P =.11). Eight patients (40%) improved by 2 points or more in their motor or sensory score and 1 point or more in the modified Rankin Disability Scale score and were considered IVIG therapy responders. They had a shorter duration of symptoms (P =.03), numb hands (P =.02), and falling episodes (P =.02), and had greater proximal leg weakness (P =.02) compared with nonresponders. In IVIG therapy responders, the ulnar motor conduction velocity was slower, ulnar and peroneal distal motor latencies were prolonged, and the frequency of conduction block was higher (13 of 36 motor nerves in responders vs 6 of 53 in nonresponders, P =.008). CONCLUSIONS: Intravenous immunoglobulin therapy was beneficial in 8 (40%) of our 20 patients with polyneuropathy and IgG monoclonal gammopathy of undetermined significance. Proximal leg weakness, short duration of symptoms, and demyelinating features on electrodiagnostic studies were associated with a response to IVIG therapy.

Adult↗
PubMed2002

Prospective investigation of a subcutaneous, implantable central venous access device for therapeutic plasma exchange in adults with neurological disorders.

Standard alternatives to antecubital access for long-term therapeutic plasma exchange, including percutaneous polyurethane or tunneled silicone catheters, are associated with complications and inconvenience for the patient. We have investigated the Bard CathLink 20, a subcutaneously implantable central venous access device, as an alternative for outpatient plasma exchange. The CathLink 20 consists of a funnel-shaped titanium port connected to a soft polyurethane-derived catheter and is accessed percutaneously using an 18-gauge catheter-over-needle Angiocath. Six patients with paraproteinemic polyneuropathies underwent 64 outpatient plasma exchanges using the CathLink 20 for access, 31 using 2 CathLink 20's (draw and return), 20 using a single CathLink 20 as the draw site and 13 using a single CathLink 20 as the return site. Mean (+/- SD) plasma removed was 3,680 +/- 551 ml in 115.2 +/- 25.3 min. Apheresis personnel were able to access the ports in 1.23 +/- 0.6 attempts per port per procedure. Six of 70 planned procedures were aborted: 3 because of failure of an antecubital access site and 3 because of catheter occlusion resolved using a thrombolytic agent. Whole blood flow rate was approximately 54 ml/min, and plasma flow rate was about 32 ml/min for 135 min. Access pressures were stable at -150 to -200 torr (P = 0.1395). Return line pressures varied between 90 and 130 torr (P = 0.0147). No patient required hospitalization during the study. Though not optimized for apheresis, the CathLink 20 provides a reasonable option for chronic apheresis patients who lack adequate peripheral venous access.

Adult↗
PubMedDate not supplied

Therapeutic apheresis in neurology critical care.

Therapeutic apheresis has been widely accepted in the treatment of neurological disorders that are understood to be mediated by humoral and/or cellular immunity. The clinical presumption is that well-established and/or unknown insults cause damage to nerves or their myelin sheaths. The rationale for apheresis treatments for these neurological disorders relates to removal of offending immune (or other) mediators, thus blunting the attack and permitting recovery of nerve and/or myelin. This review will concentrate on the role of therapeutic apheresis, in particular therapeutic plasma exchange, in neurological disorders that may frequently be seen by intensivists.

Autoimmune Diseases of the Nervous System↗