[2 year interferon therapy of metastatic carcinoid tumor]. / Zweijährige Interferon-Therapie eines metastasierten Carcinoids.

A 39 year old male patient was treated with daily 5 X 10(6) IU interferon alpha 2b s.c. for 22 months because of advanced carcinoid tumor. Objective response was achieved with greater than 50% reduction of 5-HIAA-excretion. Multiple metastases (liver, lung, bones, thyroid gland) were not progressing in size. An unintentional omission of treatment resulted in a rapid biochemical and morphological tumor progression. Reversibility was achieved with reinstitution of effective interferon therapy. Thus, interferon therapy of advanced carcinoid tumor is able to induce a long-term objective response. It seems to be superior to conventional chemotherapy.

[Catheter embolization of intrarenal arteriovenous fistula formations]. / Katheterembolisation intrarenaler arterio-venöser Fistelbildungen.

Catheter embolization of renal arteriovenous fistulas is an effective alternative treatment to surgery; general anaesthesia is not necessary and the hospitalization is limited to 2-3 days. Suitable catheters, permanent occlusion material, such as butylcyanoacrylate, and balloon occlusion technique provide a safe and successful embolization even in cases with massive arteriovenous malformations.

Plasma exchange and concomitant therapy in TTP.

Since plasma exchange was introduced in the management of thrombotic thrombocytopenic purpura (TTP) in 1977, patient survival rate has increased from 10 to 80%. However, approximately 50 subsequent case reports in the literature provide no consensus as to the optimal therapy. We review here 4 episodes of TTP in 3 patients. In all cases, treatment was started with intensive FFP plasma exchange combined with administration of antiplatelet agents and corticosteroids. Remission was achieved in 3 out of 4 episodes although all required individualization of the medication regimen. In the remaining patient, cytotoxic therapy (vincristine) and ultimately splenectomy were required to achieve stable remission. The variable clinical response to these therapeutic protocols indicates that TTP may not represent a single homogeneous disease entity but rather may involve various underlying pathologies. We conclude that the most effective present therapy for the management of TTP is daily plasma exchange with fresh frozen plasma infusions combined with antiplatelet agents and steroids. Vincristine and splenectomy should only be employed if this protocol proves ineffective.

Membrane plasma exchange: principles and application techniques.

Membrane plasmapheresis was introduced in 1978 as a new method for performing therapeutic plasma exchange. Its principal advantages over traditional techniques include speed, ease of performance, and ready adaptability to clinical centers already performing routine extracorporeal therapy. The appearance of a membrane plasmapheresis circuit (vascular access, anticoagulation, connectology) is similar to that of hemodialysis and especially hemofiltration; the operating protocols (treatment time, filtration rates, pressures, pharmacokinetics) are quite different. Particular attention must be paid to avoiding operating conditions that lead to hemolysis. In clinical use membrane plasma separation is as effective as centrifugal plasma exchange in removing plasma proteins. The sieving coefficients for proteins with a molecular weight (MW) ranging from 67,000 (albumin) to 2,400,000 (beta-lipoprotein) daltons are unity. An exchange of one patient plasma volume has been shown to cause a 55% reduction of the serum levels of intravascular proteins. There are no significant differences between membrane and centrifugal plasmapheresis in substitution fluid requirements (human albumin or fresh frozen plasma), indications for treatment and complications. The next major advance in plasmapheresis technology will almost certainly be development of a "closed loop" circuit in which filtered plasma is treated to remove the offending moiety and returned to the patient. This would eliminate both the cost and the possible side effects of replacement fluid. Membrane-based systems are already available for removing cryoglobulins or proteins with MW of at least 900,000 daltons.

Plasma exchange in systemic lupus erythematosus.

Of 20 patients who presented to our hospital with the histologically confirmed diagnosis of SLE, nine met the criteria of presence of both a rapidly progressive disease state and contraindications for conventional therapy required for admission to our plasma exchange programme. Five patients improved; two patients progressed to end-stage renal failure; two patients died as a result of complications of advanced SLE. Severe lupus erythematosus (SLE) is usually treated with a combination of steroids and cytotoxic drugs. Even when treated with high dose therapy some patients develop life-threatening complications, such as renal failure, heart failure and respiratory insufficiency. Moreover, both treatment with high dose of corticosteroids and long lasting cytotoxic therapy may produce troublesome side-effects, including severe infections, gastroduodenal ulcers, bone marrow depressions and lymphomas (1, 2). One of the manifestation of SLE is the presence of antibodies against ds-DNA and ss-DNA. These antibodies can either react with DNA bound to te basement membrane and induce an inflammatory reaction (3), or can form circulating immune complexes which deposit in tissues and may impair the function of lymphocytes or macrophages in the RES (4, 5). The presence of anti-DNA-antibodies appears to be secondary to enhanced B-cell activity along with a depression of suppressor T-cells function proteins mediating the inflammatory process, such as fibrinogen, may deposit in membranes already compromised by the disease. Even though the pathogenic mechanisms operating in SLE are not completely understood, it can be expected, from a theoretical point of view, that the extracorporeal removal of any immunopathogens could improve the disease state.(ABSTRACT TRUNCATED AT 250 WORDS)

Mass transfer in membrane plasma exchange.

In vitro and in vivo sieving coefficients (SC) have been determined for a spectrum of proteins ranging in molecular weight from 66,500 daltons (albumin) to 2.4 million (beta-lipoprotein) daltons for three commercially available membrane plasma separation devices: the Plasmaflo 0.1, Plasmaflo 02, and Plasmaflux. A model relating serum level of a protein to pretherapy level, plasma volume, plasma filtration rate, membrane SC, and duration of treatment has been used to investigate the influence of SC on exchange efficiency. Comparison of predicted and clinically obtained reductions in serum solute levels demonstrated the validity of the model. The results of the analysis suggest that all three plasma separators are capable of delivering equally acceptable therapy. The model further demonstrates the decreasing effectiveness, and increased cost in terms of replacement fluid per unit of solute removed, with prolonged treatment times.

[Treatment of emergency situations in autoimmune diseases with plasma exchange]. / Behandlung von Notfallsituationen bei Autoimmunerkrankungen mit Plasmaaustausch.

Plasma exchange has been applied successfully to treat severely ill patients with autoimmune diseases in recent years. We report on 12 patients with systemic lupus erythematosus (SLE), myasthenia gravis (MG), and Goodpasturés syndrome (GS), that have been treated with membrane plasma separation. Two to three liters of plasma were exchanged per session. Three to nine treatments were done within 1--4 weeks. Human albumin solution was used for replacement of the discarded plasma. Improvement was seen in 3 out of 5 SLE patients, in all 5 myasthenic patients and in one of the two patients with GS. Plasma exchange in combination with immunosuppressive therapy is indicated in states of active autoimmune diseases, not controllable by routine immunosuppression. For long-term treatment, however, immunosuppressive medication should be used.