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.

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.

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.

Risk of Kaposi sarcoma after solid-organ transplantation: multicenter study in 4,767 recipients in Italy, 1970-2006

Given the high prevalence of infection with human herpesvirus type 8, Italy is an area of utmost interest for studying Kaposi sarcoma (KS). We investigated the risk of KS in transplant recipients compared with the general population. A longitudinal study was performed from 1970 to 2006 in 4767 kidney, heart, liver, and lung transplant recipients from 7 Italian transplantation centers. The sample included 72.3% male patients with an overall patient median age of 48 years. Patient-years (PYs) at risk for KS were computed from 30 days posttransplantation to the date of KS, death, last follow-up, or study closure (December 31, 2007). Standardized incidence ratios (SIRs) and 95% confidence intervals were computed to quantify the risk of KS in transplant recipients compared with the general Italian population. Incidence rate ratios were computed to identify risk factors using adjusted Poisson regression. Based on 33,621 PYs, KS was diagnosed in 73 patients (62 men): 31 in kidney recipients, 27 in heart recipients, 8 in liver recipients, and 7 in lung recipients. The overall incidence was 217 cases per 10(5) PYs, with a significantly increased SIR of 125. SIR was particularly high in women (n = 34) and lung recipients (n = 428) but decreased significantly with time posttransplantation. The primary predictors of increased risk of KS were male sex, older age, and lung transplantation. A 5-fold reduction was observed after 18 months posttransplantation. After adjustment, patients born in southern Italy compared with northern Italy demonstrated a significant 2.2-fold increased risk. Our findings confirm that in the early posttransplantation period, Italian patients who have undergone solid-organ transplantation, particularly those from southern Italy and those who are lung recipients, are at greater risk of KS compared with the general population. These findings underscore the need for appropriate models for monitoring transplant recipients for KS, especially those at greater risk and, in particular, in the early postoperative period.

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 preβ-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.

Immunohistological diagnosis of drug-induced hypersensitivity nephritis

The immunohistological findings in 10 cases of DIHN and in 6 cases of R-ARF were compared with the patterns of experimental models and human examples of immunological nephritis. In most cases the simultaneous involvement of glomerular and extraglomerular structures was observed. A linear pattern on tubules together with a granular pattern on glomeruli and other structures was more frequently seen in Rifampicin adverse reactions. Direct and indirect immunofluorescence techniques performed in these last cases gave no evidence of the presence of the antigen and specific antibodies in the kidneys.

De novo malignancies after organ transplantation: focus on viral infections

Organ transplantation is an increasingly used medical procedure for treating otherwise fatal end stage organ diseases with 107,000 transplants performed worldwide in 2010. Newly developed anti-rejection drugs greatly helped to prolong long-term survival of both the individual and the transplanted organ, and they facilitate the diffusion of organ transplantation. Presently, 5-year patient survival rates are around 90% after kidney transplant and 70% after liver transplant. However, the prolonged chronic use of immunosuppressive drugs is well known to increase the risks of opportunistic diseases, particularly infections and virus-related malignancies. Although transplant recipients experience a nearly 2-fold elevated risk for all types of de-novo cancers, persistent infections with oncogenic viruses - such as Kaposi sarcoma herpes virus, high-risk human papillomaviruses, and Epstein-Barr virus - are associated with up to 100-fold increased cancer risks. This review, focusing on kidney and liver transplants, highlights updated evidences linking iatrogenic immunosuppression, persistent infections with oncogenic viruses and cancer risk. The implicit capacity of oncogenic viruses to immortalise infected cells by disrupting the cell-cycle control can lead, in a setting of induced lowered immune surveillance, to tumorigenesis and this ability is thought to closely correlate with cumulative exposure to immunosuppressive drugs. Mechanisms underlying the relationship between viral infections, immunosuppressive drugs and the risk of skin cancers, post-transplant lymphoproliferative disorders, Kaposi sarcoma, cervical and other ano-genital cancers are reviewed in details.

Combined heart and kidney transplantation: long-term analysis of renal function and major adverse events at 20 years

BACKGROUND

Combined heart-kidney transplantation (HKTx) is an accepted therapeutic option for patients with end-stage heart disease associated with severely impaired renal function. We report our long-term follow-up with this combined procedure.

PATIENTS AND METHODS

Between April 1989 to November 2009, nine patients underwent combined simultaneous (HKTx) at our center. Seven patients were males (mean age 45.2 +/- 10.12 years); seven patients were on dialysis at the time of transplantation.

RESULTS

Surgical procedures were uneventful in all patients. One patient died in the intensive care unit 41 days after transplantation. During long-term follow-up, three patients died: one due to infection and multiorgan failure 148 months after HKTx, one due to a lung neoplasm after 6 years, and one, a cerebral stroke at 34 months after transplantation. Only one patient experience renal allograft failure secondary to hypertension and cyclosporine nephrotoxicity at 10 years after HKTx with the need for renal replacement therapy. Last estimated glomerular filtration rates of all other patients was 61.3 +/- 17.4 mL/min.

CONCLUSIONS

In selected patients, with coexisting end-stage cardiac and renal failure, combined HKTx with an allograft from the same donor proved to give satisfactory short- and long-term results, with a low incidence of both cardiac and renal allograft complications.

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.

Cancer risk of aged people with HIV infection and of transplant people

20063

Background: Acquired immunesuppression due to HIV-infection or to anti-rejection therapies following organ transplantation is a well known risk factor for cancer. This increased risk has been well documented for young adults, whereas few data are available on older persons. In this study, we assessed the impact of cancer in HIV-positive persons (HIV+) and in transplant persons (TRP) who were 50 years of age or older. Methods: Data from a multi-cohort study conducted in Italy and France were analysed. Individuals ≥50 years of age were selected from the original study group constituted by 2002 HIV+ seroconverters from Italy, 6072 HIV+ from France and 2755 Italian TRP (1844 kidney, 702 heart, 159 liver and 50 lung TRP). Sex- and age-standardized incidence ratios (SIR) and 95% confidence intervals (CI) were computed to quantify the cancer risk as compared to the general population. Among HIV+, the risk of cancer was also assessed according to treatment with highly active antiretroviral therapies (HAART). Results: This analysis was based on 94 cancers diagnosed in 833 HIV+, and on 154 cancers diagnosed in 1558 TRP ≥50 years of age. The SIRs for all cancers decreased with ageing, ranging from 5.1 (95% CI: 4.0–6.5) in HIV+ aged 50–59 to 2.1 (95% CI: 1.4–3.1) in HIV+ aged 60 or older. In TRP, the SIRs for all cancer were 2.5 (95% CI:2.0–3.1) and 1.6 (95% CI: 1.2–2.0), respectively. In HIV+, the protective effect of HAART was more evident in those aged 50–59 (SIR = 6.8 in never treated and SIR = 2.4 in ever treated) than in HIV+ aged ≥60 (SIR = 2.8 and SIR = 1.6, respectively). This pattern of cancer occurrence was peculiar to virus-related cancers (e.g., Kaposi’s sarcoma, non-Hodgkin’s lymphoma, liver cancer). SIRs for lung cancer in both groups were significantly increased but did not significantly differ according to HAART and/or age. The survival of both HIV+ and TRP was significantly reduced by the diagnosis of cancer, but the difference in survival was not associated with ageing (p = 0.20). Conclusions: Aged individuals with acquired immunesuppression have a cancer pattern similar to younger persons with immunosuppression, but the burden of cancer will increase in absolute terms because of the increasing proportion of older individuals among both HIV+ and TRP.

No significant financial relationships to disclose.

[The hemodialysed patient and his/her family caregiver. Comparison of perceptions of the chronic illness]

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.

Risk of Kaposi's sarcoma and of other cancers in Italian renal transplant patients

A follow-up study of 1844 renal transplant patients in Italy showed a 113-fold increased risk for Kaposi's sarcoma. Kaposi's sarcoma risk was higher in persons born in southern than in northern Italy. Significant increases were also observed for cancers of the lip, liver, kidney and for non-Hodgkin's lymphoma.

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.

Incidence and clinical characteristics of posttransplant lymphoproliferative disorders: report from a single center

In the period 1973-1998, among 2139 allograft recipients treated with standard immunosuppression, posttransplant lymphoproliferative disorders (PTLD) developed in 19 patients (0.9%): one plasmacytic hyperplasia, two polymorphic PTLD, one myeloma, and 15 lymphomas. PTLD developed 1 year after transplantation (tx) in 14 patients. Five patients were diagnosed at autopsy, 2 were lost to follow up, 3 died before therapy could be instituted, and 1 patient has just started chemotherapy. Of the 8 evaluable patients, 2 received acyclovir and are alive in complete remission (CR) and 6 received chemotherapy +/- surgery. Of these 6, 4 died of lymphoma and/or infection, 1 died of unrelated causes in CR, and 1 is alive in CR. PTLD is a severe complication of tx, usually running an aggressive course which may preclude prompt diagnosis and treatment. Nevertheless, therapy is feasible and must be tailored on the histologic subtype. Seventy-four percent of patients were diagnosed with late-onset PTLD stressing the need for long-term follow up.

Effect of plasma cholesterol reduction by pravastatin on the functional properties of forearm arteries in hypercholesterolemic patients

BACKGROUND AND AIM

Since functional properties in the vasculature of hypercholesterolemic subjects are impaired, a six-month pravastatin treatment (20 mg/die) was tested in an open design, on the impaired unstimulated forearm arterial compliance (Un-FAC(AUC)) of 14 asymptomatic type IIa familial hypercholesterolemic patients. In order to evaluate whether FAC(AUC) changes might be related to the extent of cholesterol reduction achieved, this evaluation was carried out in five severely hypercholesterolemic patients, undergoing LDL-apheresis.

METHODS AND RESULTS

Arterial functional properties, i.e. FAC(AUC) responses to glyceryl trinitrate (GTN-FAC(AUC)) and acetylcholine (ACh-FAC(AUC), four patients) and the effects on rest and peak forearm blood flow and vascular resistance were evaluated on the non-dominant arm using plethysmographic methods, that also allow the direct assessment of the non-linear "compliance-blood pressure" curve. Selective LDL-apheresis was performed by using a dextran-sulphate column. Pravastatin effectively lowered plasma total (-16%, p = 0.002) and LDL cholesterol levels (-22%, p = 0.006 vs baseline). Rest and peak flow, basal and post ischemic vascular resistance were not affected as well as Un-FAC(AUC) and GTN-FAC(AUC). However, in the four hypercholesterolemic patients undergoing ACh infusion, there was an improvement in the ACh-FAC(AUC) of borderline statistical significativity (p = 0.056). LDL-apheresis reduced plasma total and LDL cholesterol levels by 55% and 59%, without affecting blood pressure. In this series of five patients Un-FAC(AUC) increased, the Un-FAC(AUC) rise being inversely related to the absolute reduction of plasma total (r = 0.92, p < 0.05) and LDL cholesterol (r = 0.89, p < 0.05) levels.

CONCLUSIONS

In hypercholesterolemic patients a short-term hypocholesterolemic treatment with pravastatin, although able to improve the lipid profile, cannot alter significantly blood flow, vascular resistance, Un-FAC(AUC) and GTN-FAC(AUC). A possible selective improvement in the ACh-receptor-activated signal transduction pathway has been observed and the importance of a drastic reduction of cholesterol concentrations in order to affect the Un-FAC(AUC) is suggested.

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.

Intravenous gamma globulin in refractory thrombotic thrombocytopenic purpura

We report the case of a young woman with refractory thrombotic thrombocytopenic purpura (TTP), treated with different therapies (standard therapy with plasma exchange, prostacyclin infusion, vincristine sulfate) and responding to these for brief periods. High-dose immunoglobulin (400 mg/kg/day for 5 days), on the other hand, yielded a complete response which has lasted for 14 months up to the time of this report.

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.

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.

Uremic inhibitors of erythropoiesis: a study during treatment with recombinant human erythropoietin

The effects of increasing amounts of uremic sera (US) on the growth of erythroid progenitor cells [burst-forming unit erythroid (BFU-E)] collected from peripheral blood of normal subjects were evaluated to assess the potential role of uremic inhibitors of erythropoiesis during a treatment with recombinant human erythropoietin (r-HuEpo). US were collected from 8 patients on regular dialysis with marked anemia (Hb 6 +/- 0.5 g%) before and after a treatment with high doses of r-HuEpo (from 300 to 525 U/kg/week). Standard cultures for BFU-E were performed in alpha-metylcellulose with fetal calf serum (FCS) and 4 U/ml of r-HuEpo (Cilag, Ortho). In successive cultures, US were added at increasing amounts to the standard culture in order to assess a possible inhibitory effect on BFU-E growth. Finally, in order to assess a possible lack of stimulatory factors, we partially substituted FCS with US. The addition of US collected either before or after therapy with r-HuEpo to the standard culture had no effect on the growth of BFU-E. Vice versa, the number of cultured BFU-E decreased when FCS was partially substituted with US collected before r-HuEpo. This effect was not evident when FCS was partially substituted with US collected after r-HuEpo. No significant differences were recorded in the tested sera collected before and after therapy considering erythropoietin levels and amino acid levels. We hypothesized that some other factors with erythropoietic stimulatory activity (burst-promoting activity?) may be deficient in uremic patients with marked anemia and can be induced during therapy with r-HuEpo.

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.

Predictability of low-density lipoprotein levels during apheretic treatment of hypercholesterolaemia

The efficiency and efficacy of low-density lipoprotein (LDL) apheresis performed with a dextran sulphate cellulose (DSC) regenerating unit were tested in five familial hypercholesterolaemic patients. LDL apheresis was repeated four times at both bi-weekly and weekly intervals, processing one plasma volume each time. The efficiency of the procedure (i.e., the extent of lipoprotein removal) was nearly identical with both schedules. Efficacy parameters, i.e., decreases of plasma total and LDL cholesterol (TC and LDL-C) and apo B, were highly correlated (r greater than 0.96) with preapheresis levels, allowing an accurate prediction of the absolute lipid removal in the single individual. Plasma triglycerides, high-density lipoprotein cholesterol, apo A-I and apo A-II recovered rather rapidly, reaching 91-96% of the pre-apheresis values in 48 hours; the recovery of TC, LDL-C and apo B was much slower, with a relatively rapid early phase (80% recovery after about 7 days) followed by a successive slower rise. This pattern was highly reproducible in the single patient, allowing the definition of a simple mathematical model for an accurate (error less than 20%) prediction of the individual process. Based on this model one can design the treatment schedule necessary to maintain lipid levels within the desired range in the single individual. The hypolipidaemic efficacy of DSC apheresis appears, otherwise, not to be dependent upon the procedure per se, but on other individual factors, e.g. the amount of removable lipoproteins and the rate of lipid recovery; both can be predicted with sufficient accuracy.

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.

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.

Polymorphonuclear cell phagocytosis and surface receptor modulation after extracorporeal circulation

Polymorphonuclear cells (PMN) from patients treated with hemodialysis (HD) or plasma exchange (PE) were analyzed by flow cytometry to determine modulation in phagocytic capacity and Fc-gamma and C3bi receptor expression following extracorporeal circulation (EC). Fluorescent microbeads (phi 2.02 m) were used in the evaluation of phagocytosis, and phycoerythrin conjugated Leu11c and Leu15 monoclonals identified Fc-gamma and C3bi receptors respectively. The percentage of positive cells and mean receptor density on PMN surfaces were calculated for each antibody before and after the procedures. Fc-gamma receptor expression was reduced overall in HD and PE cases, but unaffected after EC even with specific paraprotein removal. C3bi receptor was normally expressed on PMNs before and after EC, but receptor density on the cell surface increased, and phagocytosis was qualitatively and quantitatively depressed after EC. The resulting effect of EC on PMNs was therefore a temporary increase in C3bi receptor density after the procedure, which was independent of HD or PE technique, of the primary disease, and of the quality of the PE reinfusion solutions, suggesting a procedure-related effect, and a down-regulation of PMN phagocytic activity. Both effects may be related to membrane biocompatibility.

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.

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.

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.

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.

Flow cytometric study of immunocompetent cell phenotypes and phagocytosis in CAPD effluent

The immunocompetent cells from peritoneal effluent in 22 stable CAPD patients were studied for surface phenotype distribution and for phagocytic properties by flow cytometry. The following monoclonal antibody couples were employed with direct dual color immunofluorescence: HLA-DR/CD 4, CD 8/CD 11c, Leu 7/CD 16, CD 14/CD 13, and Anti-Leucocyte/CD33. The phagocytic properties of peritoneal macrophages and polymorphs (PMN) were evaluated by the ingestion of 2.02 microns O fluoresceinated microspheres. The same analyses were also performed in peripheral blood. A FACStar laser-operated flow cytometer was employed. A remarkable heterogeneity of CAPD fluid cells was demonstrated, even in the absence of any obvious infection, suggesting the possible occurrence of aborted inflammatory processes. Activated T helper cells, T suppressors (CD8+/CD11+) and Fc gamma+ cells prevailed among lymphocytes, whereas variable amounts of monocytes and PMNs were present. The phagocytic activity of CAPD fluid phagocytes ranged from very depressed to normal values, whereas it was only moderately reduced in blood, suggesting local blocking phenomena, possibly due to interfering metabolites. Flow cytometry is the method of choice for a rapid and accurate analysis of phenotypic and functional properties of cells recovered from various body fluids. This study may be helpful in evaluating local immune response mechanisms in CAPD patients.

Selective and semiselective low-density lipoprotein apheresis in familial hypercholesterolemia

Seven patients with familial hypercholesterolemia were treated fortnightly for 3 months by selective low-density lipoprotein apheresis with dextran-sulfate cellulose column (DSC). Subsequently, 4 of them were treated with semiselective double filtration. No cholesterol-lowering drugs were given. Plasma processed ranged from 39 to 58 ml/kg body weight/procedure. Fractional removals from plasma filtrate at the secondary treatment (adsorption or fractionation) for total cholesterol, high-density lipoprotein cholesterol, and albumin, respectively, were 0.84, 0.06, and 0.03 with DSC and 0.74, 0.47 and 0.35 with double filtration. Postapheresis reductions of total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were 57, 15, and 59% with DSC and 47,35, and 48% with double filtration. Both methods are suitable for clinical use, but with a 15-day treatment schedule, lowering circulating lipid fraction levels are maintained with DSC.

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.

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=1 8), 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±1 5.4%; p=0.001).

The advantage of a combined treatment is therefore either a lowered PE requirement or a tapered maintenence cytostatic dosage.