Acquired lecithin:cholesterol acyltransferase deficiency as a major factor in lowering plasma HDL levels in chronic kidney disease.

OBJECTIVES: It has been suggested that a low plasma high-density lipoprotein cholesterol (HDL-C) level contributes to the high cardiovascular disease risk of patients with chronic kidney disease (CKD), especially those undergoing haemodialysis (HD). The present study was conducted to gain further understanding of the mechanism(s) responsible for the low HDL-C levels in patients with CKD and to separate the impact of HD from that of the underlying CKD. METHODS: Plasma lipids and lipoproteins, HDL subclasses and various cholesterol esterification parameters were measured in a total of 248 patients with CKD, 198 of whom were undergoing HD treatment and 40 healthy subjects. RESULTS: Chronic kidney disease was found to be associated with highly significant reductions in plasma HDL-C, unesterified cholesterol, apolipoprotein (apo)A-I, apoA-II and LpA-I:A-II levels in both CKD cohorts (with and without HD treatment). The cholesterol esterification process was markedly impaired, as indicated by reductions in plasma lecithin:cholesterol acyltransferase (LCAT) concentration and activity and cholesterol esterification rate, and by an increase in the plasma preß-HDL content. HD treatment was associated with a further lowering of HDL levels and impaired plasma cholesterol esterification. The plasma HDL-C level was highly significantly correlated with LCAT concentration (R = 0.438, P < 0.001), LCAT activity (R = 0.243, P < 0.001) and cholesterol esterification rate (R = 0.149, P = 0.031). Highly significant correlations were also found between plasma LCAT concentration and levels of apoA-I (R = 0.432, P < 0.001), apoA-II (R = 0.275, P < 0.001), LpA-I (R = 0.326, P < 0.001) and LpA-I:A-II (R = 0.346, P < 0.001). CONCLUSION: Acquired LCAT deficiency is a major cause of low plasma HDL levels in patients with CKD, thus LCAT is an attractive target for therapeutic intervention to reverse dyslipidaemia, and possibly lower the cardiovascular disease risk in these patients.

Immunosuppression and cancer: A comparison of risks in recipients of organ transplants and in HIV-positive individuals.

The comparison of cancers occurring excessively among HIV-infected and transplanted individuals may help to elucidate the relationship between immune surveillance, viral infections, and cancer. A longitudinal study was conducted on 2002 HIV-infected Italian subjects, 6072 HIV-infected French individuals, and 2878 Italian recipients of solid organ transplants. Standardized incidence ratios (SIR) and 95% confidence intervals (CI) were computed to quantify the risk for cancer, compared with the French and Italian general populations. The SIRs for all cancers were 9.8 (95% CI: 9.0-10.6) for HIV-infected individuals versus 2.2 (95% CI: 1.9-2.5) for transplant recipients. In both groups, most of the excess risk was attributable to virus-related cancers, such as Kaposi's sarcoma (KS; SIR = 451 in HIV-positive individuals, 125 in transplant recipients), non-Hodgkin's lymphoma (NHL; SIR = 62.1 and 11.1, respectively), and liver cancer (SIR = 9.4 and 4.1, respectively). Significantly increased SIRs for anal cancer and Hodgkin's lymphoma were found only among HIV-positive individuals. Among women younger than 40 years of age, a more than 10-fold increase in cervical cancer risk was found in both groups. Among HIV-infected individuals treatment with highly active antiretroviral therapies drastically reduced SIRs for KS and NHL only. These results show that HIV-infected individuals and transplant recipients share a similar pattern of cancer risk, largely due to virus-related cancers.

Whole blood selective LDL-apheresis: a comparison of two different adsorbers.

The effects of LDL-apheresis with whole blood adsorption were compared in five patients with severe familial and ARH hypercholesterolemia, using two different sorbents, polyacrylic acid with the DALI system and dextran sulfate with the DX21 system. The patients were treated bimonthly with both systems at random. For each patient, the same number of procedures with both systems was considered, ranging from 2 to 11 for each technique. During a period of observation of 26 months, a total of 80 LDL-apheresis, 40 with the DALI system and 40 with the DX21, with equivalent volumes of treated whole blood was evaluated (mean blood volume treated: 8151 mL). Total and LDL cholesterol were effectively lowered with both techniques. The mean percentage reduction of total cholesterol and LDL-cholesterol respectively was 54.1+/-7.7% and 62.3+/-9% with the DALI system, 52.7+/-7.8% and 59.2+/-9.5 with the DX21: t-test for paired data showed p: 0.01 for LDL-cholesterol. The reduced removal of LDL-C with dextran sulfate, either within the same patient or all the patients taken together was of a very limited amount compared to polyacrylic acid. The superiority of one over the other sorbent cannot be affirmed: further studies on a higher number of procedures and patients, together with an evaluation of biocompatibility effects, compared to polyacrylic acid may clarify and make evident a significant difference in efficacy between the two systems.

[The hemodialysed patient and his/her family caregiver. Comparison of perceptions of the chronic illness]. / Il paziente emodializzato e il caregiver familiare. Percezioni a confronto sulla malattia cronica.

BACKGROUND: According to health psychology, the family caregiver (fc), i.e. the person who takes care of a hemodialysed patient, plays a pivotal role in coping with dialysis. This study explored and compared the lifestyle and the main needs of a cohort of hemodialysis patients, with reduced personal autonomy, to their fc, evaluating some psychological functional parameters, such as the perception of familial and social support, the psychological quality of life, the disability due to chronic illness, and the communication style. METHODS: An anonymous multiple versions questionnaire, administered according to the caregiver's family relationship, was given for self assessment to 54 couples of patients and related fc (spouse, son/daughter and brother/sister), mean age 66 and 60, respectively; mean dialytic patients' age: 8 years and 6 months. The questionnaire consisted of three different sections, demographics, renal disease and psychological evaluation, with 4 standard scales (Social Support Satisfaction, Marital Communication, Psychological General Well-Being Index and Evaluation of Needs). A multivariate variance analysis (MANOVA) was subsequently performed. RESULTS: Women have a higher perception of their lifestyle change after dialysis, and, in general, patients communicate more easily with their fc than vice versa. Communication problems are more common in patients with a recent diagnosis. Patients and fc mostly need a better dialogue with their nephrologists and urge some psychological help. CONCLUSIONS: The quality of the relationship between physicians, patients and their families is a key element in the process of healing.

Apheretic treatment of severe familial hypercholesterolemia: comparison of dextran sulfate cellulose and double membrane filtration methods for low density lipoprotein removal.

The two more widely available techniques for the extracorporeal removal of low density lipoproteins (LDL), dextran sulfate cellulose column and double membrane filtration, were comparatively tested in severe familial hypercholesterolemic patients, both acutely and during a continued 3-month treatment. The selective dextran sulfate procedure removed close to 60% of LDL and 16% of high density lipoproteins (HDL) upon each apheresis, vs. 42% and 32%, respectively, in the case of the semi-selective double membrane filtration. Upon long term biweekly treatments, LDL-cholesterol (LDL-C) decreased, with the selective procedure, from a pre-treatment level of 406.0 +/- 40.7 mg/dl to a value fluctuating between 295.4 +/- 33.8 mg/dl and 116.9 +/- 22.0 mg/dl (highest vs. lowest levels) whereas, in the case of double membrane filtration, LDL-C levels ranged between 334.8 +/- 39.8 mg/dl and 192.3 +/- 49.9 mg/dl. HDL-cholesterol levels were somewhat raised, to a higher extent with dextran sulfate apheresis. The LDL/HDL-cholesterol "atherogenic ratio", decreased from a pre-treatment value of 10.27 +/- 3.04 to values ranging between 3.61 and 6.82 with dextran sulfate and between 6.70 and 7.68 with double membrane plasmapheresis.

Management of lipoprotein-X accumulation in severe cholestasis by semi-selective LDL-apheresis.

Liver disorders characterized by prolonged bile stasis are often associated with the accumulation of an abnormal lipoprotein, lipoprotein-X (LP-X), in plasma. LP-X is separated in the low-density lipoprotein (LDL) density range, but lacks apolipoprotein B and does not interact with the LDL receptor; LP-X can cause hyperlipidemia, cutaneous xanthomas, and worsening of arterial disease. We report the case of a patient with severe cholestasis, markedly elevated plasma cholesterol levels (26.8 to 31.5 mmol/L), mainly due to a massive accumulation of LP-X in plasma, and diffuse xanthomas. To reduce the elevated cholesterol levels, the patient was given extracorporeal treatment aimed at removing atherogenic lipoprotein (LDL-apheresis). LDL-apheresis was performed at weekly or bi-weekly intervals, either by a semi-selective technique using filters with a defined pore diameter (double filtration, DF) or by a more selective technique using dextran-sulfate-cellulose (DSC) columns able to bind LDL. The semi-selective DF technique proved more effective than DSC, removing 48% of total cholesterol (compared to 30% with DSC), and lowering cholesterol levels to 11.1 mmol/L in 6 weeks. DF removed both LDL and LP-X from plasma, whereas DSC selectively decreased the LDL content. The reduction of plasma cholesterol levels was associated with a complete regression of the xanthomas, supporting DF apheresis as a first-choice treatment for patients with massive LP-X accumulation due to cholestasis.

Effect of familial hypertension on glomerular hemodynamics and tubulo-glomerular feedback after uninephrectomy.

Familial hypertension, glomerular hemodynamic alterations, and dysregulation of tubulo-glomerular feedback (TGFB) have all been associated with the development of chronic renal failure. In the present study we evaluated renal and glomerular hemodynamics and TGFB responses in healthy kidney donors either with or without familial hypertension, before and after nephrectomy. Para-amino-hippurate plasma clearance (CPAH) and inulin plasma clearance (CInu) were measured in 15 kidney donors before and 1 year after nephrectomy. All subjects were normotensive and were kept in a sodium-replete state. Both clearances were measured after 40 min of constant infusion of PAH and Inu, as well as 20, 30, 50, and 60 min after the intravenous administration of acetazolamide (5 mg/kg). Glomerular hemodynamics were calculated by means of the Gomez formulae. Nephrectomy caused the expected decreases in CPAH and CInu and increase in the filtration fraction (all P < .0001). The decrease in renal resistances of the remaining kidney was greater at the afferent (-24%, P = .0075) than at the efferent arteriolar level (-17%, P < .0001). The TGFB activation was not altered by nephrectomy or by familial hypertension. Effective renal plasma flow (ERPF) decrease after TGFB activation appeared earlier than glomerular filtration rate (GFR) decrease before (P = .01), but not after, nephrectomy (P = .48). The presence of familial hypertension was associated with increased glomerular pressure (P = .0004). This study suggests that uninephrectomy in healthy human subjects causes a greater decrease in afferent arteriolar resistances, but that TGFB responses are not quantitatively altered. Familial hypertension is associated with a tendency toward higher glomerular pressures.

Alterations in the HDL system after rapid plasma cholesterol reduction by LDL-apheresis.

Changes in high density lipoprotein (HDL) subfraction structure and composition were analyzed during and after extracorporeal removal of apo B containing lipoproteins in seven familial hypercholesterolemic (FH) patients. After the apheretic procedure, carried out with dextran-sulfate-cellulose columns, the plasma levels of very low density lipoproteins (VLDL), low density lipoproteins (LDL), and HDL decreased by 72%, 50%, and 19%, respectively. The free cholesterol to esterified cholesterol ratio in plasma increased, with a 26% drop in the lecithin:cholesterol acyl transferase (LCAT) activity. In the ensuing 24 hours, VLDL, HDL, and LCAT activity approached the pretreatment levels. During this phase, possibly as a consequence of increased cholesterol esterification and exchange of cholesteryl esters for triglycerides between HDL and VLDL, HDL2a particles were detected in plasma. However, these metabolic changes did not result in clearcut modifications in the HDL2-HDL3 subfraction distribution. These findings clearly demonstrate that rapid changes in the plasma VLDL-LDL levels affect several processes involved in the HDL metabolism, but confirm that the HDL system, in spite of a considerable plasticity, displays a marked stability of the HDL2-HDL3 subfraction distribution.

Prothrombin-antibody coexistent with lupus anticoagulant (LA): clinical study and immunochemical characterization.

The patient is a 23 y.o. man with acute nephritis and bleeding at presentation. Laboratory data consistent with the diagnosis of systemic lupus erythematosus. A lupus anticoagulant was found: tissue thromboplastin inhibition test (TTIT) ratio 3.4; diluted Russell viper venom (DRVV) ratio 2.6. Hypoprothrombinemia (FII:C less than 1%; FIIR:Ag 5%) was present; prothrombin survival time (FII concentrate infusion 60 U/kg): t1/2 approximately to 9 hours. A prothrombin antibody was identified: it is not neutralizing but forms an immunecomplex with prothrombin. The antibody was characterized as IgG2, IgA, k, lambda. The prothrombin survival time indicates that the hypoprothrombinemia is due to the clearance of the prothrombin-antiprothrombin complex in vivo.

Effect of n-3 polyunsaturated fatty acids on cyclosporine pharmacokinetics in kidney graft recipients: a randomized placebo-controlled study.

Highly concentrated marine polyunsaturated fatty acids (n-3 PUFA), affecting the lipids and lipophilic drugs metabolism, can interfere with cyclosporine (CyA) pharmacokinetics. This prospective, randomized and placebo-controlled, double-blind study involved 42 kidney graft recipients. From day +1, 21 pts (E) received 6 g n-3 PUFA (85% EPA + DHA, Esapent, Pharmacia) and 21 pts (P) received placebo (olive oil), both reduced to 3 g from day +30 on. A quadruple immunosuppressive regimen was employed. Plasma creatinine, lipids and CyA pharmacokinetics were investigated 1, 3, 6, 9 and 12 months after graft. The two groups were comparable for age, weight, M/F ratio, hypertension prevalence and baseline lipids. Active treatment did not affect total and HDL-cholesterol, but significantly lowered triglycerides (E:120 +/- 12 vs P:166 +/- 21 mg/dl, p < 0.0001). At one year, E pts had lower creatinine than P (1.26 +/- 0.06 vs. 1.88 +/- 0.2 mg/dl, p < 0.05), comparable CyA dosage, and a larger CyA area under the curve (AUC) (n.s.), with a higher blood peak level (Cmax) (p < 0.04) and less variance in time to peak (n.s.). The larger AUC in the E group at all intervals and the better pattern of plasma creatinine, with no rise in blood pressure, provided evidence of better CyA absorption and metabolism in n-3 PUFA supplemented kidney graft recipients.

Fluorocytometric analysis of anti-HLA class 2 autoantibodies in patients with lupus nephritis.

Systemic lupus erythematosus (SLE) patients are known to produce a variety of autoantibodies (AAb), some of which may be directed against immunocompetent cells. Anti-B cell autoimmunity may encompass reactivity against HLA-class 2 molecules, which are also expressed on kidney tissue. We studied 15 patients with moderate to severe renal involvement and 5 lupus patients with no clinical renal disease, in order to detect the presence of anti-HLA class 2 AAb. Flow cytometry was employed in an inhibitory assay using patient sera, autologous cells and two anti-class 2 monoclonals, to establish the specificity of anti-B cell AAb. Seven out of 15 nephritis patients had detectable anti-class 2 AAb with an epitopic heterogeneity, as demonstrated by different degrees of inhibition on the binding of non-overlapping monoclonals. The specificity of the reaction was confirmed by the lack of inhibition of non-class 2 antibody binding. The presence of such AAb was not correlated with disease activity but with the presence of a diffuse proliferative glomerulonephritis on renal biopsy. Anti-class 2 AAb may be a marker of SLE diffuse proliferative nephritis.

Clinical relevance of fractionation characteristics in cascade filtration.

Plasmapheresis performance is improved in the treatment of hyperviscosity syndromes with one of the several cascade filtration techniques (CF), intended for plasma fractionation and reinfusion of albumin-enriched plasma filtrate to the patients, avoiding the need for exogenous reinfusion solutions. A retrospective open analysis of 103 CF, performed by dead-end mode, in 14 patients with macroglobulinemia, cryoglobulinemia, multiple myeloma and other diseases, has been performed. Protein fractions removals have been calculated, normalized to the treatment of one plasma volume, compared in different macromolecular diseases and according to the different plasma fractionators employed. [table: see text] Protein removal is partially dependent of the surface area of the fractionator, but a wide variability has been reported, mainly depending on the underlying macromolecular disease.

Removal of antiacetylcholine receptor antibodies by protein-A immunoadsorption in myasthenia gravis.

Myasthenia Gravis is an autoimmune disease in which autoantibodies to the acetylcholine receptor interfere with neuromuscular transmission. Plasma exchange is effective in temporarily relieving the symptoms of the disease, but for repeated use the lack of selectivity and need for replacement fluids (which increases the risk of contracting viral diseases) are important drawbacks. Staphylococcal protein A, a potent ligand for immunoglobulins, that interacts negligibly with other plasma proteins, appears to be an optimal candidate for removing antiacetylcholine receptor antibodies, which are mostly IgG. We treated three patients with severe immunosuppression-resistant myasthenia gravis with protein A immunoadsorption. Neurological impairment significantly improved in all patients. After immunoadsorption of 1.5-2 plasma volumes per session, the mean percentage reductions for serum IgG and specific autoantibodies were 71% and 82% respectively. No major side effects occurred. Protein A immunoadsorption appears to be a safe, efficient and effective alternative to plasmaexchange for selected myasthenic patients requiring prolonged apheresis.

Impaired efficacy of selective LDL-apheresis in primary biliary cirrhosis.

Low-density lipoprotein apheresis (LDL-apheresis) was done with either cascade filtration (DF) or dextran sulfate cellulose adsorption (DSC) in a patient with primary biliary cirrhosis who developed severe dyslipidemia associated with cholestasis and accumulation of lipoprotein-X (LP-X). The extracorporeal treatment was initially performed weekly, and resulted in a sharp drop in total cholesterol from 1038 to 430 mg/dl. During the next four months the patient was treated every 10-15 days, and pre-apheresis cholesterol levels were maintained between 438 and 505 mg/dl, until an orthotopic liver transplantation was successfully performed. With semi-selective DF a mean 47.1% of total cholesterol was removed per procedure compared to 30.0% with DSC, although the volume of treated plasma was 38.0 vs 49.9 ml/kg body weight. The changes in plasma cholesterol levels during DSC and DF showed that the kinetics of cholesterol removal were similar with both techniques, but the efficacy differed; DF removed both LDL and LP-X from plasma, whereas DSC selectively lowered the LDL content. Cascade filtration may therefore be considered as a first-choice treatment for patients with LP-X accumulation due to cholestasis.

Efficacy of a combined treatment with plasma exchange and cytostatics in macroglobulinemia.

Monthly plasma exchange (PE) sessions have been carried out in 3 patients with advanced Waldenström macroglobulinemia, in order to reduce electrophoretic M band under 2g/100 ml. When PE was combined to low doses of cytostatics (n = 18), 3 procedures per session were required to obtain a mean 57.4 +/- 12.3% IgM reduction, from 4.2 +/- 1.2 to 1.7 +/- 0.5 g/100 ml. A mean 61.5 +/- 13.1% IgM reduction, from 5.5 +/- 1.3 to 2.1 +/- 1 g/100 ml, was obtained in 64 procedures carried out as the only therapy in 12 sessions, with 5.3 procedures requirement per monthly session. IgM percent reduction 24 hours after PE was greater with combined treatment (45 +/- 9.7 vs. 28.9 +/- 15.4%; p = 0.001). The advantage of a combined treatment is therefore either a lowered PE requirement or a tapered maintenance cytostatic dosage.

Renal abnormalities reverted by plasma exchange in thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is usually accompanied by renal disfunction presumable due to diffuse thrombotic occlusions in the microcirculation. Two patients with TTP and slight renal failure with proteinuria and microscopic hematuria, were treated by repeated plasma exchanges with fresh frozen plasma, associated with prednisone and cyclophosphamide in one case, and prednisone alone in the other one. Platelet count, hematocrit and lactic dehydrogenase reverted to normal values within the fourth exchange; circulating immune complexes were never detected. Plasma factor stimulating prostacyclin activity lacked in only one patient and returned to normal levels after plasma exchange without being affected during a hematologic relapse. Renal function and urinary abnormalities reverted to normal by the end of plasma exchange and nine and six months renal and hematologic follow-up is still negative. Renal abnormalities in TTP seem to take advantage of early treatment by plasma exchange, which further to replacement of missing plasma factors, can account for the removal of toxic substances to be further investigated on.

Performance evaluation of cascade filtration with high flow rate recirculating plasma on the secondary filter.

Cascade filtration (CF) has been performed in 67 on-line procedures in 9 normolipidemic patients with paraproteinemic disorders. A modified dead-end technique has been employed, with high flow rate recirculating plasma on the plasma fractionation filter (QD recycled CF), and an albumin-rich, globulin-poor filtrate was reinfused into the patient. Postprocedure recoveries were 81 +/- 15% for albumin, 55 +/- 23% for IgM and 48% for cryocrit, with an increase in A/G ratio from 1.8 to 2.1. An improvement was observed also in antiatherogenic/atherogenic lipoproteins ratio, suggesting a possible use of this technique in the treatment of familial hypercholesterolemia. Plasma primary separation was obtained by centrifugation or by filtration, and no significant differences were observed on subsequent protein fractionation process. An albumin priming of the plasmafractionation circuit accounted for an additional 13% saving in postprocedure level. Different surface area secondary filters have been employed: with larger surfaces, larger volumes were processed without any increase in the waste volume and with reduced need for washouts, but with an additional loss of small molecules possibly due to entrapping onto the membrane.

Different cascade filtration operating modalities in clinical use.

Cascade filtration (CF) can be performed in either the single-pass or dead-end configuration. The distinction, as predicted by experimental models, is that solute removal is lower but constant in the former, and higher but variable with the quantity of filtrate in the latter. Moreover, unpredictable plugging reduces permeability during operation. It is therefore unclear which configuration is preferable in clinical use. In four cryo- and three macroglobulinemic patients, the data of 10 dead-end CF (QP) and 11 modified single-pass CF with high flow rate recycling plasma (QD) were compared. Both groups had similar starting values. Centrifugal primary plasma separation was performed. No exogenous reinfusions were used. Either 0.8 and 1.2 sq.m. surface secondary filters were employed. The ratio of plasma processed to patients' plasma volume was 1.1 +/- 0.3 in QP, and 0.94 +/- 0.09 in QD. The mean percentage removals of albumin, IgG and IgM respectively were 25.8 +/- 9, 32 +/- 17 and 47.5 +/- 26% in QP, 30.5 +/- 12, 40.5 +/- 19 and 48 +/- 17.5% in QD: albumin vs IgM p less than 0.025 in QP and p less than 0.02 in QD. A/G ratio increased from 1.6 +/- 0.5 to 2.06 +/- 0.6 in QP, and from 1.5 +/- 0.3 to 1.7 +/- 0.3 in QD. Plugging occurred in both groups, requiring 2.3 +/- 1.8 washouts/run in QP vs 1.5 +/- 1.2 in QD. IgM removal was comparable. Removal of albumin and IgG was slightly higher in QD. Similar performances can be obtained with either technique in clinical use, provided an adequate fractionation surface is available.

Plasma exchange in acute renal failure by cortinarius speciosissimus.

Mushroom poisoning by Cortinarius speciosissimus (C. spec.) leading to irreversible renal failure has been described; in a recent report, an expected bad prognosis has probably been overcome as a result of the very early use of hemoperfusion. In Sep. '81, a healthy couple of wife and husband, both aged 38, had gastrointestinal symptoms 2 days after ingestion of C. spec. On day 8 an acute renal failure developed and the same day, before dialysis, plasma exchange (PE) was undertaken. Renal biopsies disclosed a common pattern of tubular necrosis, scattered infiltrates and interstitial edema. Diuresis and partial recovery started in the man on day 10, while failure persisted over six months in the woman. Further to individual sensitivity to C. spec. toxins, renal damage, once established, may be irreversible, irrespectively of early treatment. Limited usefulness of PE in C. spec. poisoning is probably related to the long latency between ingestion and occurrence of the first renal symptoms.

Prophylactic plasma exchange in burn treatment.

The first cause of death in burned patients is still sepsis. A great number of studies point out a serious immunodeficiency due to several circulating mediators. Nowadays early excision and plasma exchange appear to be the most efficient procedures in order to remove from the patient these circulating agents. Therefore in this study the authors have treated 8 patients (average age 25 years), who presented an average of total burned surface of 49%, with plasma exchange performed early after injury. The results of PMN and lymphocyte function tests showed a significant therapeutic correction of these parameters in patients treated with plasma exchange. The clinical observations agreed with the results: in 7 patients with positive outcome, no invasive infections were recorded. The positive results obtained warrant further investigation with this procedure.