Plasmaphoresis and plasma exchange in the treatment of hyperlipaemia and xanthomatous neuropathy in patients with primary biliary cirrhosis

The scientific basis and future of lipoprotein apheresis

Lipoprotein apheresis plays a vital role in the management of the severe hyperlipidemias that predispose to atherosclerosis. Determinants of efficacy are the acute reduction in lipoproteins achieved by each apheresis procedure, their frequency, and the fractional catabolic rates and hence pool sizes of low-density lipoprotein (LDL) or lipoprotein (a) (Lp(a)) of the patient being treated. A useful criterion of the efficacy of apheresis plus lipid-lowering drug therapy is the decrease in the interval (time-averaged) mean of serum total or LDL cholesterol or Lp(a) between procedures, expressed as the percent decrease in the interval means below the maximal levels of these lipoproteins when off all treatment. Recent advances in lipid-lowering drug therapy may diminish the use of lipoprotein apheresis but will not abolish its unique role as a therapeutic "last chance saloon," especially for children and pregnant women with homozygous familial hypercholesterolemia.

Removal and Recovery of Cholesterol in Thermofiltration

Thermofiltration, a system of membrane plasmapheresis for LDL apheresis, was applied to the treatment of hypercholesterolemic patients to assess its lipid lowering potential, clinical feasibility and post-treatment lipid recovery.

Plasma separated by a membrane separator was warmed above physiologic temperature, filtered with a plasma filter and returned to the patient on-line without requiring supplemental plasma product infusion. One calculated plasma volume was treated. Treatment schedules were weekly, biweekly or monthly. Patients treated by thermofiltration in this study were diagnosed as type II hypercholesterolemia. Reductions and sievings of high density lipoprotein (HDL) cholesterol and low density lipoprotein (LDL) cholesterol were evaluated. In addition, post-treatment solute recovery was assessed.

The reduction ratios of HDL cholesterol and LDL cholesterol were 0.31 ± 0.08 and 0.58 ± 0.08, respectively (mean ± S.D. of 7 patients). Sieving coefficients of the plasma filter for HDL cholesterol and LDL cholesterol were 0.62 ± 0.12 and 0.03 ± 0.02, respectively (mean ± S.D. of 32 treatments). Cholesterol reduction fitted well to a single pool model. HDL cholesterol recovered significantly faster than LDL cholesterol and LDL cholesterol recovery differed among individuals. For some patients total cholesterol and LDL cholesterol levels were lowered by the biweekly treatment while for others the weekly treatment was required. Significant removal of LDL cholesterol with sparing of HDL cholesterol was achieved without the requirement for plasma products.

Novel strategies and therapeutic options for the management of primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease. It has a varied course of progression ranging from being completely asymptomatic to aggressive disease leading to cirrhosis and resulting in liver transplantation. In addition, symptoms can be debilitating and can have a major impact on quality of life. For decades, there was only one anti-cholestatic agent available to target this disease and that was only effective in around half of patients, with little or no effect on symptoms. With increasing understanding of the pathogenic mechanisms of PBC and potential targets for drug treatment, pharmaceutical companies have shown a greater interest in this rare disease. A large number of novel therapeutic molecules have been developed and are currently being evaluated. In this review article all the novel molecules in use and in trials targeting cholestasis and symptoms in PBC are discussed.

Plasmapheresis exerts a long-lasting antipruritic effect in severe cholestatic itch

BACKGROUND & AIMS

The amelioration of refractory cholestatic pruritus after plasmapheresis has been reported in single patients. Here, we analyse the efficacy of plasmapheresis in a cohort of patients with primary biliary cholangitis (PBC).

METHODS

Seventeen consecutive patients with PBC (age range 39-85 years, 16 females, 9 with cirrhosis) and refractory pruritus underwent 129 plasmapheresis procedures during 40 admissions. Pruritus was quantified by the 10-point numeric rating scale (NRS) before and after plasmapheresis, as well as ~30 and ~90 days later.

RESULTS

The mean pruritus before plasmapheresis did not differ between patients with and without cirrhosis (P>.05). Cirrhotics presented, however, with significantly higher serum alanine aminotransferase (ALT), aspartate transaminase (AST), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP) and bilirubin before plasmapheresis. Plasmapheresis decreased itching to NRS≤5 in all but five admissions: Mean pruritus decreased from 8.3±1.4 to 3.1±2.2 (P<.0001) in the entire cohort. It also led to a significant decrease in serum ALT, ALP, AST, GGT (all P<.001) and bilirubin (P=.002). Antipruritic effect persisted throughout the 90-days follow-up (P<.0001). The amelioration of pruritus was not affected by the presence of cirrhosis.

CONCLUSIONS

Plasmapheresis is a promising method for reducing intractable itch in a significant proportion of PBC patients regardless of liver fibrosis. Long-lasting improvement of symptoms requires repeated procedures.

Clinical, biochemical, and immunohistochemical features of necrobiotic xanthogranulomatosis

AIMS

To describe the clinical features of two patients with paraproteinaemia and necrobiotic xanthogranulomatosis together with detailed immunohistochemistry of the lesions in one.

METHODS

The clinical history and results of biochemical investigations of the patients were retrieved from the files. Immunohistochemistry was used to investigate the expression of macrophage and mast cell markers, amyloid A and P, S-100 protein, and apolipoprotein AI and B in xanthogranulomatous skin lesions from patient 2. In addition, protein A-sepharose chromatography was used to separate serum from patient 2 and apolipoprotein B and the IgG paraprotein were measured in the fractions eluted.

RESULTS

Monocytes/macrophages comprised the major cellular component of the lesion, and unusually for xanthomata, areas of collagen necrosis were also seen. Activated mast cells were present at the margins of macrophage clusters and adjacent to areas of collagen necrosis. Serum paraprotein was bound to low density lipoproteins as judged by protein A-sepharose chromatography, and was also located within macrophagic foam cells of the lesion on immunohistochemistry.

CONCLUSIONS

These observations demonstrate many features similar to atherosclerosis including collagen necrosis and mast cell activation.

Review article: liver support systems in acute hepatic failure

The treatment of acute hepatic failure has developed rapidly over the last 40 years, reducing morbidity and mortality from this syndrome. Whilst this has been partly attributed to significant improvements in the specialist medical management of these patients, advances in surgical techniques and pharmaceutical developments have led to the establishment of successful liver transplantation programmes, which have improved mortality significantly. This review will examine the clinical impact of alternative methods that have been used to provide extra-corporeal hepatic support. Non-biological, bio- logical and hybrid hepatic extra-corporeal support will be explored, offering a comprehensive historical overview and an appraisal of present and future advances.

Indications for and timing of liver transplantation

The tremendous success of OLT as a highly effective treatment for patients with end-stage liver disease has resulted in a rapid increase in the number of candidates for the procedure. Refinements in organ preservation, improvements in surgical technique and immunosuppression, and better postoperative management have contributed to improved survival rates. The discrepancy between the paucity of organs and the increasing numbers of potential recipients will continue to worsen until there are extraordinary breakthroughs in providing alternatives to human whole-organ livers, such as xenografts or cultured hepatocyte infusions. For now, the vast majority of patients with life-threatening liver disease are not likely to receive a liver graft. Thus, the issues of patient selection and timing of OLT have become even more relevant. Prompt referral to a transplant center is not only in the patient's best interest, but also it has been shown to be cost-effective. Over the last 30 years, it has become clear that hepatic malignancy, initially a common reason for OLT, should be an indication for transplantation only in highly selected individuals. The role of adjuvant chemotherapy needs to be defined, and proven treatment alternatives need to be developed. New antiviral agents may enable a large group of patients with chronic hepatitis B to be successfully transplanted, placing even greater demands on the already limited supply of donor livers. Hepatitis B appears to be species specific, and it is conceivable that xenotransplantation from a nonsusceptible donor species may confer protection to HBV reinfection, eliminating the problems of an inadequate donor supply. Until novel approaches, including xenotransplantation, gene therapy, or replacement of hepatic function by cultured hepatocyte infusions, become a widespread reality, future allocation policies may highlight outcome as well as urgency as a fundamental variable to determine if transplantation is reasonable. Survival rates have been shown to fall with advancing levels of urgency, resulting in a conflict between equity and efficacy in organ allocation. As waiting lists for liver transplantation continue to grow, it is becoming increasingly apparent that patients must be referred to a transplant center earlier in the course of liver disease.

Different apheresis methods in the treatment of hypercholesterolemia in primary biliary cirrhosis: a case report

The two different modes of low-density lipoprotein (LDL) apheresis, cascade filtration (CF) and dextran-sulfate cellulose (DSC) adsorption, were compared for efficiency of cholesterol removal in a patient with severe hypercholesterolemia due to primary biliary cirrhosis (PBC). Decrement in the total cholesterol level by the DSC method was less than that by the CF method. Apolipoprotein B was decreased to almost null by both modules whereas the decrease in albumin was much greater in the second filter of the CF method than in the DSC column. Lipoprotein X which constituted the major portion of serum cholesterol in PBC became negative by passing plasma through the second filter. The CF method was preferred to the DSC method for removal of lipoprotein X, but albumin substitution was mandatory to prevent the decrease of serum albumin in the CF method.

Reduced serum lipoprotein(a) levels in patients with primary biliary cirrhosis

Lipoprotein(a) (Lp(a)) is a unique lipoprotein, elevated serum levels of which are independently associated with an increased risk of coronary heart disease (CHD). Primary biliary cirrhosis (PBC) is often associated with high serum cholesterol, itself a risk factor for CHD. Despite this, patients with PBC are thought to have a lower than expected incidence of CHD. We hypothesised that this may be related to low serum levels of Lp(a) in PBC patients. This was investigated by collecting fasting blood samples from 42 patients with PBC, 39 age- and sex-matched subjects with non-PBC liver disease and 432 community control subjects. Serum was analysed for total cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol and apolipoproteins A1 and B (apo A1 and apo B). Lp(a) was measured by an enzyme-linked immunosorbent assay (ELISA) technique. There was a significant reduction of Lp(a) concentrations in the PBC group compared with the healthy controls (median value 28.5 mg/l vs. 75.0 mg/l, P < 0.005) and between the non-PBC liver disease group (median value 52.0 mg/l) and control group (P = 0.001). Within both the liver disease and PBC patient groups there were significant negative correlations between Lp(a) levels and bilirubin (R = -0.564, P < 0.001 and R = -0.395, P = 0.010 respectively). This preliminary study has demonstrated reduced Lp(a) levels in PBC patients which may be a contributory factor to explain a possible cardioprotective effect in such patients, despite elevated LDL cholesterol levels.

Effect of rifampicin in the treatment of pruritus in hepatic cholestasis

Pruritus in hepatic cholestasis has been suggested to be secondary to a high concentration of serum bile acids. Rifampicin, which inhibits the uptake of bile acids by hepatocytes, has been used to treat pruritus. To determine the efficacy of rifampicin as a treatment for refractory pruritus, the medical records of 33 children (median age 25 months, range 4-135; 19 boys) with chronic cholestasis liver disease (21 with Alagille's syndrome, eight with progressive intrahepatic cholestasis, one with extrahepatic biliary atresia, one with an inborn error of bile acid metabolism, and one with cryptogenic cirrhosis) were reviewed retrospectively. The median dose of rifampicin was 5(4-10) mg/kg/day. The median duration of intake was 36(4-120) weeks. Complete relief of pruritus was noted in five (15%) patients and a partial response in 12 (36%). Overall, no significant difference was noted in the laboratory parameters before and after treatment with rifampicin. In the 21 patients with Alagille's syndrome, however, a significant decrease in alkaline phosphatase was seen before and after one and six months of starting treatment. No adverse side effects were seen. Rifampicin appears to be effective in the treatment of refractory pruritus. A prospective study is warranted to assess further the effect of rifampicin treatment in children with hepatic cholestasis.

Effects of long-term rifampicin administration in primary biliary cirrhosis

The effects of rifampicin treatment (10 mg.kg-1.day-1) on pruritus and cholestasis were evaluated in 16 patients with primary biliary cirrhosis and pruritus followed up for 2-24 months. Assessment of pruritus severity, liver tests, aminopyrine breath test, and bile acids was done at 2 weeks and every 3 months after the beginning of the study. Two patients (12.5%) were withdrawn after 2 months of treatment because they had hepatitis caused by rifampicin. Four patients were withdrawn after 4 months because of liver transplantation (3 cases) and the development of leg edema associated with administration of rifampicin. The remaining 10 patients received therapy for 14.4 +/- 0.7 months and did not experience side effects. Pruritus improved in all patients and disappeared in 11 patients (79%) after 3 months of treatment. Moreover, all patients followed up for more than 1 year were free of pruritus. The alkaline phosphatase level decreased significantly, and the aminopyrine breath test results increased significantly after 2 weeks of treatment (P less than 0.001) and did not change thereafter. In the 9 patients treated for 15 months, alkaline phosphatase levels decreased to 63% of the basal levels and aminopyrine breath test results increased to 153% of baseline values. Transaminases, gamma-glutamyltransferase, and total bile salt levels decreased significantly after 2 weeks of treatment but returned to baseline after 3 months. No changes in bilirubin and cholesterol levels were observed. It is concluded that long-term rifampicin treatment is effective for relieving pruritus in primary biliary cirrhosis, but liver enzymes should be monitored to detect drug-induced hepatitis.

Liver, lipoproteins and disease: II. Clinical relevance of disordered cholesterol metabolism in liver disease

The alterations in the concentration and composition of lipoproteins that occur in liver disease indicate the central role of the liver in lipoprotein metabolism. A number of studies have characterized plasma lipoproteins in patients with liver disease, although in most cases the underlying molecular defects responsible for the changes are still undetermined.

Selective removal of cholesterol by plasmapheresis and the progression of atherosclerosis

There is a strong correlation of plasma cholesterol levels with the risk of coronary heart diseases as shown by epidemiologic studies. This study was undertaken to evaluate the effect of plasma cholesterol lowering on the progression of atherosclerosis in the homozygous Watanabe heritable hyperlipidemic (WHHL) rabbit. The effect of cholesterol lowering, which was accomplished by thermofiltration (on-line plasma separation with plasma filtration at 39 degrees C) was evaluated by comparison between treated and untreated control groups. Thermofiltration reduced significantly the mean plasma level of total cholesterol (284 vs. 655 mg/dl, P = 0.0005) and the percent aortic area occupied by atherosclerotic plaque (15.0 vs. 44.2%, P = 0.0003). The total lipid and cholesterol contents in the aortas in the treated group were also significantly lower than those in the control group. Microscopically, thickness measurements of the lesions showed that the mean thickness of the fibrous cap and the ratio of the thickness of the intima to that of the media were smaller for the treated group than the control group. This study demonstrated the slowing or stopping of the progression of atherosclerosis by lowering the plasma total cholesterol level in WHHL rabbits.

Intensive plasmapheresis as an alternative therapy for intractable pruritus of primary biliary cirrhosis

Primary biliary cirrhosis is a chronic disease of presumed autoimmune etiology, generally associated with other systemic abnormalities such as scleroderma, characteristic of Sjogren's syndrome and Raynaud's syndrome, for which pruritus is the most troublesome symptom. Treatment of this disease is a major unsolved problem. Although the use of cholestyramine has been effective, a considerable number of cases are refractory to the drug and to other agents such as corticosteroids, azathioprine and penicillamine. Plasma exchange has proven to be a useful option in four female patients with primary biliary cirrhosis--two with grade III histology and the other two with grade IV disease and intractable pruritus. The procedure was well tolerated and no side effects were observed. There was a temporary but significant attenuation of pruritus and improvement of melanoderma. Intensive plasma exchange is proposed as an alternative therapy in primary biliary cirrhosis with refractory pruritus.

Dyslipoproteinaemia of liver disease

Hepatic diseases differ from most other causes of secondary dyslipidaemia in that the circulating lipoproteins are not only present in abnormal amounts but they frequently also have abnormal composition, electrophoretic mobility and appearance. Pre-beta and alpha bands can be absent on electrophoresis in all types of liver disease although material in the VLDL and HDL ranges can be isolated in the ultracentrifuge. Cholestatic liver disease has been the most extensively studied and the hyperlipidaemia can be extreme with marked elevations of free cholesterol and phospholipids. This results largely from the presence of LP-X, an abnormal LDL, with a vesicular structure that appears in rouleaux formation under the electron microscope. It is virtually specific for cholestasis and familial LCAT deficiency. The LDL, however, is heterogeneous and may also contain a large triglyceride-rich particle (LP-Y) as well as more normal-looking particles, which are none the less depleted in cholesteryl esters and rich in triglycerides. Indeed, when patients with cholestasis are hypertriglyceridaemic the excess triglyceride is to be found predominantly in these two LDL fractions rather than in VLDL. HDL in cholestasis may contain disc-like particles, similar to those newly secreted by the liver and intestine, as well as more normal-looking spherical particles. In extrahepatic obstruction concentrations of HDL and its major apolipoproteins, apoAI and apoAII, are frequently reduced, although a subfraction rich in apoE is often found. In all but the latest stages of chronic intrahepatic cholestasis due to primary biliary cirrhosis, however, HDL, especially HDL2, concentrations are increased, probably due to the presence of a circulating inhibitor of HL. Many of these lipoprotein changes found in cholestasis resemble those of familial LCAT deficiency, although the hyperlipidaemia is not usually so severe in the latter condition. Indeed, in patients with cholestasis but well-preserved LCAT activity many of the characteristic lipoprotein changes, such as LP-X, LP-Y and discoidal HDL, may not be seen. In acute hepatocellular disease, such as alcoholic or viral hepatitis, it is not unusual for the patient to go through a cholestatic phase and many of the same lipoprotein changes may be seen. In cirrhosis without cholestasis the patients are not usually significantly hyperlipidaemic and in advanced cases cholesterol and apoB levels may be reduced. Although LCAT activity and the proportion of plasma cholesterol esterified may also be markedly reduced, LP-X is not usually seen, possibly because the flux of free cholesterol and phospholipid (lecithin), the LCAT substrates, is relatively low. Discoidal HDLs are often present.(ABSTRACT TRUNCATED AT 400 WORDS)

Hyperviscosity syndrome in a hypercholesterolemic patient with primary biliary cirrhosis

A 45-yr-old woman with primary biliary cirrhosis, xanthomatosis, and marked hypercholesterolemia developed symptoms of the hyperviscosity syndrome on three separate occasions. On presentation, she had a plasma total cholesterol concentration of 53.40 mM (2065 mg/dl) and a relative serum viscosity of 2.9. Following three courses of plasma exchange in a 5-day period, the total cholesterol level decreased to 6.75 mM (261 mg/dl) and the viscosity to 1.3. The cutaneous xanthomata were markedly diminished 1 wk following plasma exchange. Despite therapy with colestipol (30 g/d), the hyperviscosity syndrome developed 147 days later. This cycle recurred again 137 days after colestipol was discontinued. Serum viscosity and total cholesterol concentration were highly correlated during the postexchange or accumulation phases (R = 0.95, 95% CI: 0.85, 0.98) and during the exchange or interventional phases (R = 0.95, 95% CI: 0.84, 0.99). Serum viscosity was less significantly correlated with total serum protein (R = 0.84; 95% CI: 0.55, 0.95) or with plasma triglyceride (R = 0.63; 95% CI: 0.26, 0.81). There were no significant correlations of red cell mass, plasma fibrinogen levels, or serum bile salts with viscosity. Subfractionation of plasma into lipoprotein classes showed 45% of total cholesterol in the lipoprotein X fraction and a presumptive slow alpha-lipoprotein species. It is postulated that both the hyperviscosity syndrome and rapid resolution of xanthomata in the patient may be attributable to the physiology of her abnormal lipoprotein particles.

Primary biliary cirrhosis

Primary biliary cirrhosis is a chronic liver disease of unknown etiology characterized by slowly progressive intrahepatic cholestasis due to an inflammatory destruction of small intrahepatic bile ducts. The clinical course of PBC is variable ranging from a few years in rapidly progressive cases to a normal life-expectancy in a proportion of asymptomatic cases. The typical patient is a middle-aged woman who may present with pruritus, increasing pigmentation of the skin, and eventually jaundice. The level of serum alkaline phosphatase is almost invariably elevated, serum mitochondrial antibodies are present in more than 90 per cent, and an elevated serum IgM is usually present. PBC is associated with many immunologic abnormalities and appears to be a classic autoimmune disease. Some of the immune defects may be epiphenomena; others such as a marked defect in suppressor T cell function seem to be related to the pathogenesis of the disease. All drug therapy that is aimed at slowing the disease process is experimental. A place for immunosuppressive drugs in the management of PBC would be anticipated. However, no drug has to date been definitively shown to have a beneficial effect on the disease. Currently, the main treatments used are aimed at preventing or correcting the complications of intractable cholestasis. Patients with PBC and evidence of hepatic decompensation and/or poor quality of life make good candidates for liver transplantation. The current aim of therapy is to find an effective regime of immunosuppression that will make hepatic transplantation redundant for this disease.

Comparison of rifampicin with phenobarbitone for treatment of pruritus in biliary cirrhosis

The anti-pruritic effects of rifampicin (10 mg/kg) and phenobarbitone (3 mg/kg) were assessed in 22 patients with primary biliary cirrhosis in a crossover randomised clinical trial. Each agent was given for 14 days, with a 30-day washout period between treatments. 21 patients completed the course of rifampicin and 18 that of phenobarbitone; rifampicin was withdrawn from 1 patient when anaemia and renal failure developed, whereas 3 patients stopped taking phenobarbitone because of a rash and the 4th merely refused the drug. Rifampicin had a greater anti-pruritic effect than phenobarbitone. The symptom improved in 19 patients taking rifampicin and in 8 taking phenobarbitone, the degree of improvement being greater with rifampicin than with phenobarbitone. Pruritus disappeared in 9 patients receiving rifampicin, and three of them were free of itch when switching over to phenobarbitone. Both drugs were equally effective in inducing hepatic microsomal function but rifampicin has the additional effect of reducing cholestasis. Its anti-pruritic effect should be tested in long-term clinical trials.

Role of plasmapheresis in primary biliary cirrhosis

Five patients with primary biliary cirrhosis and prolonged cholestasis underwent intensive plasmapheresis. The indications for plasmapheresis included intractable pruritus or hypercholesterolemia and xanthomatous neuropathy. Patients noted a rapid improvement of pruritus and fatigue which was sustained as long as plasmapheresis was continued. Cholesterol levels were lowered an average of 10.3 mmol/l and xanthomata were reduced in three of four patients. Two patients with painful neuropathy caused by xanthomata experienced relief of this symptom. The liver and spleen size were not affected by plasmapheresis, and activities of aminotransferases, alkaline phosphatase and titres of mitochondrial antibody remained unchanged. We conclude that plasmapheresis has a role in the therapeutic management of patients with advanced primary biliary cirrhosis who are disabled by the complications of pruritus, xanthomatous neuropathy, or hypercholesterolemia with xanthoma formation.

The clinical effectiveness and safety of chronic plasmapheresis in patients with primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic nonsuppurative, destructive cholangitis, whose etiology is unknown. Morbidity arises early from pruritus and later from hypercholesterolemia with xanthoma formation. Therapy is supportive and directed at the complications of cholestasis. Plasmapheresis has been reported to benefit patients with hyperlipidemia and PBC; thus a pilot study of plasmapheresis utilizing the Haemonetics Model 30 with replacement by albumin and saline was conducted. Five patients (four female and one male) with a mean age of 43 (range 29-58) and a mean duration of illness of 9.5 years (range 6-21) with marked jaundice, xanthomas, xanthelasma, hepatomegaly, fatigability, anorexia, and pruritus, as well as mild nausea were studied. Peripheral neuropathy was present in two patients. Two patients had splenomegaly. Two patients had an associated Sjogren syndrome. All patients had high serum bilirubin, alkaline phosphatase, and cholesterol levels and mild elevations in aspartate amino transferase and alanine amino transferase activities. Immune complexes measured in four patients were present. Antimitochondrial antibody titers were significant in all patients. Patients underwent a mean of 63 plasmapheresis procedures over a mean of 112 weeks removing a mean of 94.7 liters of plasma. No serious toxicity was seen. All patients showed a reduction in pruritus, xanthomas, xanthelasmas, and serum cholesterol values. The two patients who had evidence of Sjogren syndrome noted subjective improvement. All patients who had fatigue, anorexia and nausea also noted moderate improvement. There was no change in hepatomegaly or splenomegaly in patients demonstrating such organomegaly. Liver function did not change significantly. Overall, four patients had improvement in their condition and one patient achieved stability.(ABSTRACT TRUNCATED AT 250 WORDS)

Therapeutic apheresis. Applications and future directions

The past 10-15 years have been witness to major technological achievements in the field of therapeutic apheresis. Concurrently, a large number of diseases, primarily with an immunological basis, have been treated with apheresis. In this paper, we review the various applications of therapeutic apheresis, adverse reactions associated with the mode of therapy, and future research directions. Several representative diseases are also discussed in detail.

Xanthomatous neuropathy of liver

A 36-year-old man with juvenile-onset diabetes mellitus developed cholestatic hepatitis of unknown cause, possibly drug-induced. He remained jaundiced for four months, until he died unexpectedly. At autopsy, severe and macroscopically identifiable xanthomatous neuropathy was found in the liver; it involved the unmyelinated nerves in the hilus and in all portal tracts examined. Microscopic evidence of minimal extrahepatic involvement of unmyelinated nerves was also found. Somatic nerves were affected by diabetic neuropathy but not by xanthomatous neuropathy. The condition seems to be a rare complication of diseases that are characterized by accumulations of lipids.

Plasma exchange in primary biliary cirrhosis

The symptoms of patients with primary biliary cirrhosis are frequently intractable to traditional therapy. Three patients are reported in whom several symptoms were alleviated by plasma exchange, using a Hemonetics Model 30 cell separator.

Effect of intessive plasmapheresis on the plasma cholesterol concentration with familial hypercholesterolemia

Plasmapheresis was studied as a means of reducing the serum cholesterol concentration in 3 hypercholesterolemic patients who each underwent courses of intensive plasmapheresis with removal of 250--500 ml of plasma each day for 5--9 days. In one homozygous Type II patient, the serum cholesterol concentration decreased from 609 +/- 45 mg/100 ml (mean +/- SEM) to 365 +/- 17 mg/100 ml (40% decrease, P less than 0.05) with two different courses of plasmapheresis. In the two other patients with non-homozygous hyperbetalipoproteinemia the serum cholesterol concentration decreased from 289 +/- 27 mg/100 ml to 205 +/- 19 mg/100 ml (29% decrease, p less than 0.05). After cessation of treatment, the cholesterol concentration returned to pre-treatment levels in 10--13 days in the homozygous patient and 7 days in one non-homozygous hyperbetalipoproteinemic patient; clofibrate (2 g/day) in this patient was associated with a smaller reduction of the cholesterol concentration with plasmapheresis and an increased rate of return of pre-treatment levels after plasmapheresis was stopped. Sustained plasmapheresis for 6 days in the other non-homozygous hyperbetalipoproteinemic patient resulted in a new approximate "steady state" with a serum cholesterol concentration of 176--199 mg/100 ml compared with a pre-plasmapheresis value of 227 mg/100 ml. The response of the plasma cholesterol levels to plasmapheresis was subjected to kinetic analysis based on a current model of the regulation of lipoprotein metabolism.

Plasma exchange in the management of homozygous familial hypercholesterolaemia

Two young women with homozygous familial hypercholesterolaemia and coronary and aortic atheroma were treated by repeated plasma exchange, using a continuous-flow blood-cell separator, for 4 and 8 months. A pronounced reduction in plasma cholesterol and low-density lipoprotein (L.D.L.) concentrations was achieved by exchanging each patient's plasma with cholesterol-free plasma protein fraction (B.P.), at 3-weekly intervals on an outpatient basis. By pre-labelling the patients' cholesterol with 14-C and comparing the specific activity of the cholesterol in adipose tissue with that in plasma, evidence was obtained of an influx of tissue cholesterol into plasma after each exchange. There was no side-effects and both patients lost their angina. Plasma exchange offers a new and practical approach to the long-term management of this lethal disorder and may also provide information about the possible reversibility of human atheroma.