Plasmapheresis in the treatment of glomerulonephritis

Role of therapeutic plasmapheresis in ANCA-associated vasculitis

Plasma exchange, or plasmapheresis, is a treatment method that developed over a period of two decades and involves the removal and replacement of a patient's circulating plasma. The aim of treatment is to remove disease-associated molecules and therefore interrupt disease progression. This article summarizes the developmental history of this treatment and then looks in more detail at data on the use of plasma exchange in treating antineutrophil antibody (ANCA)-associated vasculitis. The eight randomized trials and the Cochrane Systematic Review on treating renal vasculitis are summarized to show that plasma exchange may be effective in this disease, specifically in reducing the development of end-stage kidney disease (ESKD) by approximately 40%. The plasma exchange and glucocorticoid dosing in the treatment of anti-neutrophil cytoplasm antibody associated vasculitis (PEXIVAS) study is a currently enrolling study aiming to answer some of the outstanding questions relating to the use of this treatment in ANCA-associated vasculitis.

Plasma exchanges in the treatment of rapidly progressive glomerulonephritis associated with chronic dental infection

A patient is described in whom rapidly progressive, crescentic (in 80% of the glomeruli) glomerulonephritis was associated with chronic dental infection. Eradication of the infection as the sole form of therapy failed to arrest the rapidly advancing renal failure. Institution of plasma exchanges and immunosuppression was accompanied by an abrupt reversal of the renal function and a remission, which until now has lasted for two years.

Plasmapheresis with a substitution solution of human serum protein (5%) versus plasmapheresis with a substitution solution of human albumin (5%) in patients suffering from autoimmune diseases

Therapeutic plasma exchange (TPE) has been used extensively for over 2 decades to treat a variety of autoimmune and congenital diseases and is now widely accepted. The primary objective of this study was to compare the clinical efficacy of two plasma exchange preparations, human serum protein (HSP) and human albumin (HA). Twenty-four patients in the following disease categories underwent TPE using either HSP (Biseko, 5%) or HA (5%): systemic lupus erythematosus, 8; glomerulonephritis, 8; myasthenia gravis, 2; Guillain-Barré-syndrome, 2; recurrent iritis, 1; pemphigoid, 1; uveitis, 1; and vascular retinitis, 1. There was no statistically significant difference in the average number of TPEs needed in the HSP group (13.5) and HA (13.8) measured over the first 6 weeks of treatment. The secondary parameters, in particular the immunological parameters IgG and IgA, provided evidence that plasma exchange with HSP may have some advantages over HA, and confirmatory studies in a larger group of patients are indicated. Adverse events during TPE occurred in both the HAS group (4 patients) and the HA group (4 patients). However, patients in the HSP group were older (12.3 years), were suffering from more complicated autoimmune diseases, and the number of occasions (days) on which these were reported (6 days) was less than in the HA group (11 days). One patient in the HA group died from septic-toxic circulatory collapse on Day 49 due to an infection with resistant strains of Staphylococcus aureus. Infections in other patients did not occur; all showed considerable improvement in their symptoms and completed the study in good general condition.

Plasmapheresis in treatment of acute oligoanuria in crescentic glomerulonephritis

Plasmapheresis therapy can provide an approach in the treatment of crescentic glomerulonephritis by mechanically removing nephritogenic factors from the circulation, both antiglomerular basement membrane antibodies and circulating immune complexes as well as antineutrophil cytoplasmic antibodies (ANCAs). We present our experience with plasmapheresis treatment in patients with acute oligoanuria caused by crescentic glomerulonephritis. We used membrane plasmapheresis to treat 11 patients with crescentic glomerulonephritis with more than 80% crescent formation on biopsy and with acute onset of the disease and acute oligoanuria. The immune complex form of the disease was documented in 7, the antiglomerular basement membrane antibodies mediated (anti-GBM) form in 2, the ANCA-associated form in 1 case, and the recurrent anti-GBM form in 1 patient. Plasmapheresis was performed 2-3 times weekly using Bellco BL 500 and Gambro 2000 PF plasma filters. The total number of plasma exchanges (2,000-2,200 ml each) for each patient was 5-9. The treatment was associated with steroids and cyclophosphamide. The improvement of renal function with the start of diuresis and significant decrease of creatinine from the range of 786-1,301 microM at the start of the treatment was noted in 5 of the 11 patients. The duration of remission without hemodialysis was 6-12 months. Treatment with plasmapheresis in cases with recurrent anuria was without benefit. We can conclude that plasmapheresis can delay end-stage renal failure in cases with acute onset of crescentic glomerulonephritis.

The treatment of glomerulonephritis in children

The results of treatment of glomerulonephritis (GN) in childhood with oral corticosteroids, immunosuppressive drugs, anticoagulants and the newer regimens of pulsed, high-dose intravenous methylprednisolone and plasma exchange are reviewed and compared with the natural history of the untreated condition. Poststreptococcal GN and the nephritis of Schönlein-Henoch purpura need no specific treatment unless extensive glomerular crescents are present. The progression of mesangiocapillary GN can probably be slowed or even reversed with long-term, alternate-day steroid therapy. As in adults, recovery of renal function in GN due to antibody to glomerular basement membrane can be achieved in some patients using plasma exchange, but only those in whom some renal function is still present when treatment is started. In rapidly progressive (extracapillary) GN with crescents, "traditional" therapy with oral steroids, immunosuppressive drugs and anticoagulants reduces renal mortality from 85%-90% to about 50%, while pulsed methylprednisolone and plasma exchange improve the outcome further, mortality falling to about 25%. It is recommended that children with crescentic GN and deteriorating function be treated initially with pulsed methylprednisolone, followed by plasma exchange in those who fail to respond or who deteriorate following temporary response to pulse therapy. Treatment must be given early in the course of the illness if good results are to be obtained.

Comparison of filtration to continuous-flow centrifugation for plasma exchange

The Asahi Plasmaflo Hollow Nylon Fibre Filtration System (n = 13) was directly compared to the NCI-IBM 2990 Continuous-Flow Blood Fraction Separator (n = 10) for plasma exchange. The systems were equally efficient in achieving plasma separation. There were significant differences favouring filtration for clearance of fibrinogen (P less than 0.05), and the fourth component of complement (P less than 0.01). Greater loss of urea (P less than 0.05) was found after plasma exchange, using the cell separator. The flow characteristics were markedly different. In a standardised 4-L plasma exchange, filtration took place at 35 ml/minute, with a procedure time of 109 +/- 45 minutes in contrast to centrifugation at a plasma flow collection rate of 19 ml/minute, requiring 208 +/- 17 minutes. This time advantage for the former procedure was offset by 195 minutes required to regenerate the hollow nylon fibre unit and a further 90 minutes required for cleaning under strictly controlled aseptic techniques prior to reuse. Each filter was regenerated at least twice and reused without infection, but there was incremental loss of filtration efficiency demonstrated by decreasing clearance of an intravascular marker dye. In two of the 13 procedures using the Plasmaflo system, serious reactions necessitated termination of the procedure; this did not occur using the cell separator. Restriction of the number of times that the filter unit could be regenerated without loss of efficiency, the prolonged time required for regeneration and cleaning, coupled with the need for artificial vascular access to meet high blood flow rates required, limit the usefulness of this technique for plasma exchange.

A radioimmunoassay for the detection of circulating anti-glomerular basement membrane antibodies

A fluid phase radioimmunoassay (RIA) has been established for the detection of circulating anti-glomerular basement membrane (GBM) antibodies. Antibodies were detected by binding with a collagenase solubilised, immunochemically purified, radiolabelled extract of human particulate GMB. Sera from 108 patients with a variety of histological types of glomerulonephritis (GN) were assessed for the presence of antibodies. Likely positive sera were those from patients with clinical features of rapidly progressive glomerulonephritis (RPGN) with crescentic or diffusely proliferative GN and linear staining of their GBM's with IgG. Thirty one of 35 sera from such patients were positive in the RIA. Sera from 14 patients with RPGN but with granular IgG deposition (i.e. immune complex related GN) were all negative for anti-GBM antibodies as were sera from 59 patients with a variety of non-crescentic non RPGN without linear IgG. Comparison of the RIA with conventional indirect immunofluorescence (IIF) showed that the RIA had a higher detection rate of antibodies in likely positive sera (19/21 RIA: 16/21 IIF) lower false positive detection rate with sera from patients without GN (0/26 RIA: 2/26 IIF) and was three to four times more sensitive in serial dilution studies.

Accessible plasma exchange using membrane filter - a successfully treated case of TTP with repeated plasma exchanges

Plasma exchanges with a hollow-fiber type plasma filter were attempted in a variety of diseases. The unit was easily assembled and the procedures were safely carried out by our dialysis personnel after some instruction. Approximately 2 liters of fresh frozen plasma were used during each plasma exchange and about the same amount of plasma was removed from the patient in 1.5 to 2 hours. This resulted in 66% replacement of patient's albumin on one occasion. Fifty-four plasma exchanges were done in seven patients. The procedure was well tolerated by all patients with only occasional muscle cramps or itching, which were treated with calcium gluconate infusion or antihistamines, respectively. A successfully treated case of TTP in which we used repeated membrane plasma exchanges combined with conventional treatment is also reported.

Plasma exchange: a selective form of blood-letting

The technique of, and indications for, plasma exchange are presented. This selective form of plasma removal has re-established "blood-letting" in medical therapeutics on a scientific basis. It is the most appropriate therapy when hyperviscosity or haemostatic failure complicate immunoproliferative disease. Plasma exchange is also a significant advance in the management of fulminant forms of autoimmune disease, but in many other conditions it must be regarded as experimental.