PubMed Health⌕ Search

Biomedical subjects

A A Kaplan

Publications and source records attributed to A A Kaplan.

At least 19 recordsLinked to original sources
PubMed2001

Apheresis for renal disease.

Many primary renal diseases are associated with either antibody deposition within the glomerulus or an antibody associated autoimmunity, as may be seen with certain vasculitidies. Examples of these diseases include Goodpasture's syndrome, cryoglobulinemia, antineutrophil cytoplasmic antibody positive syndromes, and other forms of rapidly progressive glomerulonephritis. Immunoglobulins also may be nephrotoxic to the tubules such as is the case with myeloma related light chains. Given the rapid removal of immunoglobulins by therapeutic plasma exchange, this modality has been considered an appealing management option in the treatment of these renal diseases. Although not classically considered as autoimmune diseases, thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are related syndromes which often involve the kidneys. Although previously unexplained, it has been long appreciated that therapeutic plasma exchange (PE) can be a useful treatment for these microangiopathic hemolytic anemias, but the most recent insights into their pathogenesis suggest that PE may be beneficial by replacing a missing enzyme or removing pathogenic autoantibodies.

Adult↗
PubMed2001

Impact of therapeutic plasma exchange on cyclosporine kinetics during membrane-based lipid apheresis.

Cyclosporine is used widely as an immunosuppressant in transplant recipients and for various autoimmune diseases. In some cases, these patients require therapeutic plasma exchange (TPE). Cyclosporine is known to be highly bound to lipoproteins, and their removal by TPE would be expected to have an impact on drug dosing. We studied cyclosporine kinetics in a 54-year-old woman who is status post-cardiac transplant and has been receiving weekly TPE for familial hypercholesterolemia. We obtained serial measurements of cyclosporine, low-density lipoproteins, and high-density lipoproteins at scheduled times related to the dosing of the medication on days that she received TPE versus a day she did not. We also measured cyclosporine, low-density lipoprotein, and high-density lipoprotein levels in the fixed volume (3.5 L) of the discarded plasma. Our results show a similar rate of decline of serum cyclosporine levels on TPE days as compared with a day without TPE. Net cyclosporine in the discarded plasma was found to be approximately 1 mg per treatment or less, a relatively insignificant amount when compared with the ingested daily dose of 150 to 250 mg twice a day. Despite substantial removal of lipoproteins, there is minimal impact of TPE on serum levels of cyclosporine, and dosage adjustment is not needed for patients undergoing this procedure.

Blood Component Removal↗
PubMed2001

Role of the nephrologist in the intensive care unit.

Intensive care units (ICUs) are increasingly becoming a focal point for tension between medical specialists. In an extreme approach to this issue, some ICUs have become closed units managed by intensivists, with other specialists, such as nephrologists, having a restricted supportive role. The nephrologist, a subspecialist with broad skills in general internal medicine, has trained and appropriately can serve as the primary physician for patients with significant renal failure and end-stage renal disease in multiple hospital settings, including the ICU. Sick and complex hospitalized patients offer ample opportunity for a collaborative interaction between the nephrologist and intensivist in the ICU.

Continuity of Patient Care↗
PubMed2001

Shunt nephritis from Propionibacterium acnes in a solitary kidney.

Since its initial description in 1965, immune complex glomerulonephritis associated with ventriculoatrial shunts (VAS) has been reported widely in the literature. The most common incriminating organism is Staphylococcus epidermidis, but less often, an organism generally regarded as nonpathogenic, such as Propionibacterium acnes, has been noted as the cause. Shunt infection usually occurs within a few months after placement or manipulation of the shunt, and shunt nephritis (SN) develops gradually over months to years after. Treatment involves mandatory removal of the shunt and antibiotics; prognosis is variable. We report a case of SN with P acnes that is unusual because of its occurrence in a solitary kidney 6 years after shunt placement, persistently negative blood cultures, and normal complement levels. Percutaneous biopsy of a solitary kidney should be considered if it is expected that the result may guide therapy of progressive renal failure.

Aged↗
PubMed2001

Therapeutic apheresis for the renal complications of multiple myeloma and the dysglobulinemias.

Disordered immunoglobulin synthesis can result in a variety of different types of renal pathology. Multiple myeloma is often associated with the overproduction of light chains which may result in toxicity to the renal tubules and acute renal failure. Patients with mixed cryoglobulinemia will have renal involvement which is most often in the form of a membranoproliferative glomerulonephritis. Renal involvement in macroglobulinemia is relatively uncommon, but IgM thrombi can be so voluminous as to occlude the glomerular capillary lumen. In each of these examples, therapeutic plasma exchange has been found to be a useful adjunct to the eventual chemotherapy required for the definitive treatment of these disorders.

Cryoglobulinemia↗
PubMed2000

Therapeutic apheresis for cancer related hemolytic uremic syndrome.

Hemolytic uremic syndrome (HUS) can be seen as a result of disseminated cancer, as a consequence of chemotherapy, or in association with bone marrow transplantation (BMT). Further distinction can be made when the clinical presentation is that of an acute, fulminant course with rapidly progressive renal failure or that of a sub-acute form with a slow progression of renal involvement. Each of the different etiologies (cancer, chemotherapy, or BMT) and each of the two basic clinical presentations has its own prognosis. There are no randomized, controlled studies to elucidate the role of therapeutic apheresis for cancer-related HUS. Hemolytic uremic syndrome related to disseminated cancer is most often a terminal event and is not commonly treated with apheresis procedures, although there are anecdotal reports that plasma exchange may be beneficial. Chemotherapy and drug-related HUS have a prognosis that is strongly dependent on the severity of the presentation, but even in the most severe cases may respond to either immunoadsorption or plasma exchange with fresh frozen plasma (FFP). Finally, BMT-related HUS has a poor prognosis but may respond to immunoadsorption, plasma exchange, or a combination of the two.

Antineoplastic Agents↗
PubMed1999

Therapeutic apheresis for renal disorders.

Many primary renal diseases are associated with either antibody deposition within the glomerulus or an antibody associated autoimmunity, as may be seen with certain vasculitidies. Other immunoglobulins may be nephrotoxic or glomerulopathic; such may be the case with myeloma related light chains or cryoglobulins. Given the rapid removal of immunoglobulins by therapeutic plasma exchange, this modality has been considered an appealing management option in the treatment of these autoimmune related renal diseases. Although not classically considered as autoimmune diseases, thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are related syndromes which often involve the kidneys. In many cases therapeutic plasma exchange has been found to be a useful treatment modality for these microangiopathic hemolytic anemias. This paper will provide a concise review of the renal indications for therapeutic plasma exchange.

Anti-Glomerular Basement Membrane Disease↗
PubMed1999

Extracorporeal treatment of thrombotic microangiopathy: a ten year experience.

We reviewed 24 episodes of thrombotic microangiopathy (TMA) representing 22 patients from July 1989 to July 1998. Nine cases presented with a community acquired (CA group) thrombotic thrombocytopenic purpura or hemolytic uremic syndrome (TTP/HUS), 3 cases were related to pregnancy (P group), 10 cases were compatible with TMA after bone marrow transplantation or chemotherapy (BMT/C group), and 2 cases had a background of scleroderma (SC group). Twenty episodes were treated exclusively with therapeutic plasma exchange (TPE) using fresh frozen plasma (FFP) replacement. In the BMT/C group, 4 patients underwent immunoadsorption with the Prosorba protein A column in addition to TPE. The CA, P, and SC groups had favorable outcomes with 78% (7 of 9), 100% (3 of 3), and 100% (2 of 2) survival, respectively. Despite intensive therapy, there was only 1 survivor in the BMT/C group (1 of 10). Successful outcome required up to 57 TPE treatments. We could not document any benefit to immunoadsorption with the Prosorba protein A column.

Adolescent↗
PubMed1998

Carboplatin-related hematuria and acute renal failure.

Cisplatin is a potent tubular toxin with a high incidence of nephrotoxicity. Carboplatin is considered less nephrotoxic but can still cause tubular injury and interstitial nephritis in patients who have been previously treated with cisplatin. The affected individuals usually have nonoliguric renal failure with a urine output of more than a liter per day. We present a 57-year-old white woman with no history of renal disease who underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy for stage IC ovarian carcinoma. One month later, she received chemotherapy with paclitaxel (Taxol) and carboplatin. On the following day, she developed frank hematuria and flank pain associated with a diminished urine output. Intravenous pyelogram (IVP) showed bilateral hydronephrosis with a total blockage of dye flow at the level of intraureteral lucencies consistent with bilateral blood clots. Her coagulation profile and uric acid was normal. Her acute renal failure (ARF) spontaneously resolved in the following 24 hours, with a brisk diuresis presumably due to clot lysis. The follow-up IVP showed a resolution of obstructive changes. A review of the literature shows a previous case in which high doses of carboplatin were implicated as the cause of hemorrhagic cystitis, presumably by toxicity to transitional epithelium of the bladder. We believe that the current case represents carboplatin-induced damage to the transitional epithelium in the renal pelvi and ureters causing gross hematuria and blood clots, resulting in bilateral ureteral obstruction and hydronephrosis.

Acute Kidney Injury↗
PubMed1998

Successful treatment of cisplatin-induced hemolytic uremic syndrome with therapeutic plasma exchange.

Cisplatin is a known cause of hemolytic uremic syndrome (HUS). The acute, fulminant form of cisplatin-induced HUS is almost always fatal. We present a 67-year-old Hispanic woman who was treated with cisplatin for squamous cell carcinoma of the tongue. Three days after receiving the treatment, she presented with increasing fatigue, decreased urine output, and confusion. Physical examination was remarkable for tachycardia of 130 beats/min, peripheral edema, and mental obtundation. Laboratory investigations showed a white cell count of 5,500/microL, hemoglobin level of 9.6 g/dL, hematocrit of 29.6%, and platelet count of 13,000/microL. Schistocytes were present on peripheral smear. Screening for disseminated intravascular coagulation was negative. Serum chemistry values included blood urea nitrogen 111 mg/dL, creatinine 3.8 mg/dL, and lactate dehydrogenase (LDH) 927 IU. The patient underwent hemodialysis and therapeutic plasma exchange (TPE), using fresh frozen plasma (FFP). Dialysis was no longer required after the fifth day. TPE was performed daily until the platelet count normalized on the 13th day, after which intertreatment intervals were extended until normalization of LDH levels on the 50th day. We conclude that the normally fatal, fulminant form of cisplatin-induced HUS can be successfully treated with standard TPE, using FFP replacement.

Aged↗
PubMed1997

Therapeutic plasma exchange for the treatment of rapidly progressive glomerulonephritis.

Therapeutic plasma exchange (TPE) has been widely accepted as a successful means of removing the antiglomerular basement membrane (anti-GBM) antibodies that result in the rapidly progressive glomerulonephritis (RPGN) of Goodpasture's syndrome. TPE has also been investigated as a means of removing the immune complexes associated with the glomerulonephritides of systemic lupus erythematosus, IgA nephropathy, Henoch Schönlein purpura, and cryoglobulinemia. Recently, an antineutrophil cytoplasmic antibody (ANCA) has been implicated in the pathogenesis of RPGN associated with such diseases such as Wegener's granulomatosis and periarteritis nodosa. ANCA has also been found in many cases of RPGN formally considered to be idiopathic. The identification of this autoantibody has given new credence to the possibility that TPE may be beneficial in the treatment of these diseases. This article reviews the data regarding the use of TPE for RPGN.

Antibodies↗
PubMed1997

Extracorporeal blood purification in the management of patients with hepatic failure.

With the increasing success of orthotopic liver transplantation, the time has come for a reassessment of the role of extracorporeal blood purification in the management of patients with liver failure. In those patients with combined liver and kidney failure, both standard hemodialysis and the newer continuous renal replacement therapies have been found to be helpful in maintaining fluid, electrolyte, and acid base balance. In those patients with liver failure but without kidney dysfunction, extracorporeal purification techniques have been found useful for the removal of hepatic toxins and in facilitating the replacement of clotting factors. This review will outline the rationale and documented utility of a wide variety of blood purification modalities used in the management of patients with liver failure.

Blood Chemical Analysis↗
PubMed1996

Extracorporeal blood purification in the treatment of acute renal failure with multiorgan involvement.

It has been more than 35 years since the early use of dialytic techniques for the treatment of acute renal failure. Considering the survival of patients who would have clearly succumbed to renal failure, attempts were made to determine at what level of uremic toxicity it would be beneficial to offer dialysis on a prophylactic basis. Those early attempts at defining a preventive strategy seemed to provide an improved survival by limiting incidence and severity of hemorrhage and sepsis. Subsequently, measurable advances have been difficult to attain, and the prognosis of complicated acute renal failure remained dismally poor. More recently, continuous renal replacement techniques were developed to offer a more physiologic treatment to those patients who were the most critically ill and unstable. These treatments offered the potential for a better tolerated fluid removal and a more constant control of electrolyte and acid-base balance. Other potential advantages included the use of more biocompatible membranes and the convective mode of solute transfer with its inherently greater removal of larger molecular weight substances such as the vasodilatory and inflammatory cytokines. Another approach has been to use extracorporeal purification to lower the levels of endotoxin, a goal which can be accomplished by either standard plasma exchange or, more elegantly, the use of selective adsorption columns. Despite the promise of these methodologies, the lack of an acceptable grading system for the severity of critical illness has hampered investigators who have tried to prove the eventual advantage of one blood purification technique over another.

Acute Kidney Injury↗
PubMed1996

Protein losses in continuous renal replacement therapies.

Continuous renal replacement therapy (CRRT) has become a popular treatment modality but may have the disadvantage of producing substantial protein losses. With use of the Biuret method, a relatively insensitive assay, dialysate/ultrafiltrate protein losses have been reported to be as high as 1.3 g/L. With CRRT outputs of up to 50 L/day, these values would amount to protein losses of up to 65 g/day. In this study, dialysate/ultrafiltrate protein losses were reanalyzed by using a highly sensitive microprotein reagent (pyrogallol red) considered to be more accurate than previously available methods. Twenty-two dialysate/ultrafiltrate samples were obtained from Amicon-20 Diafilters or Fresenius F-80 dialyzers during continuous venovenous hemofiltration (CVVH) or continuous venovenous hemodialysis/hemodiafiltration (CVVHD/F). Mean hourly output for all treatments was 1637 +/- 694 mL/h. Mean protein concentration for all 22 dialysate/ultrafiltrate samples was 4.2 +/- 4.0 mg/dL. Mean dialysate/ultrafiltrate protein concentrations were similar for the Amicon 20 (3.4 +/- 4.4 mg/dL, N = 9) and the Fresenius F-80 (4.7 +/- 3.9 mg/dL, N = 13) (P = not significant). Protein losses were higher during convection-based CVVH (6.0 +/- 5.1 mg/dL, N = 10; range, 1 to 15 mg/dL) than during the mixed convection and diffusion-based CVVHD/F (2.7 +/- 1.9 mg/dL, N = 12; range, 0 to 6 mg/dL) (P = 0.049). Mean serum protein concentration at the time of dialysate/ultrafiltrate sampling was 4.7 +/- 1.8 g/dL. There was a weak, but statistically significant correlation between the dialysate/ultrafiltrate samples and the corresponding value for serum protein (r = 0.468, P < 0.03). It was concluded that protein losses during CRRT treatments are substantially lower than previously reported, are dependent on the serum protein concentration and the predominant nature of solute removal (convection versus diffusion), and can vary between 1.2 and 7.5 g/day.

Blood Proteins↗
PubMed1995

Dialysate protein losses with bleach processed polysulphone dialyzers.

We measured dialysate protein losses from polysulphone dialyzers undergoing repetitive processing with bleach and formaldehyde. The entire dialysate was collected during the first, fifth and tenth use of F-80 dialyzers. Dialysate protein concentration was 1.5 +/- 0.4 mg/dl N = 11 +/- SEM) during the first use, 2.1 +/- 0.3 mg/dl during the fifth use and 3.6 +/- 0.5 mg/dl (N = 10) during the tenth use. In a follow-up study, dialyzers were evaluated for up to 25 uses. After 12 to 15 uses dialysate protein was 7.9 +/- 0.8 mg/dl (N = 13), after 16 to 20 uses; 12.0 +/- 1.2 mg/dl (N = 13) and after 23 to 25 uses; 19.9 +/- 2.1 mg/dl (N = 5). Mean dialysate volume was 83.9 +/- 1.1 liters (N = 63) yielding total protein losses of up to 20.7 grams per treatment. Dialysate albumin losses, which were unmeasurable during the first use of the dialyzers, revealed a similar increase with reuse resulting in a mean value of 14.4 +/- 3.2 mg/dl after 23 to 25 reuses (N = 5). Dialysate beta-2 microglobulin (beta 2m) levels were 1.05 +/- 0.13 mg/l for dialyzers bleached < 10 times (N = 32) versus 1.54 +/- 0.15 mg/liter for dialyzers bleached > 10 times (N = 31, P < 0.02 vs. < 10 reuses). A random sampling of dialyzers processed without bleach for 8, 14, 15, 24 and 25 reuses revealed minimal protein losses, ranging from 1.4 to 2.7 mg/dl with no relation to reuse number and no measureable albumin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Thrombotic thrombocytopenic purpura in pregnancy: successful treatment with plasma exchange. Case report and review of the literature.

Thrombotic thrombocytopenic purpura (TTP) is a rare syndrome which presents typically with thrombocytopenia, microangiopathic hemolytic anemia, central nervous system symptoms, fever, and renal abnormalities. The diagnosis of TTP in pregnancy previously carried a poor prognosis and a high fetal mortality when presenting early in gestation. This case report describes the earliest presentation of TTP in pregnancy (6 weeks of gestation) we could identify in the literature treated successfully with a prolonged course of plasma exchange. The differential diagnosis and the pathogenesis of TTP in pregnancy are reviewed. Therapeutic options and data regarding the removal of pregnancy-related hormones by plasma exchange are presented.

Diagnosis, Differential↗