Red blood cell exchange in patients with sickle cell disease-indications and management: a review and consensus report by the therapeutic apheresis subsection of the AABB.

BACKGROUND: A prior practice survey revealed variations in the management of patients with sickle cell disease (SCD) and stressed the need for comprehensive guidelines. Here we discuss: 1) common indications for red blood cell exchange (RCE), 2) options for access, 3) how to prepare the red blood cells (RBCs) to be used for RCE, 4) target hemoglobin (Hb) and/or hematocrit (Hct) and HbS level, 5) RBC depletion/RCE, and 6) some complications that may ensue. STUDY DESIGN AND METHODS: Fifteen physicians actively practicing apheresis from 14 institutions representing different areas within the United States discussed how they manage RCE for patients with SCD. RESULTS: Simple transfusion is recommended to treat symptomatic anemia with Hb level of less than 9 g/dL. RCE is indicated to prevent or treat complications arising from the presence of HbS. The most important goals are reduction of HbS while also preventing hyperviscosity. The usual goals are a target HbS level of not more than 30% and Hct level of less than 30%. CONCLUSION: Although a consensus as to protocol details may not be possible, there are areas of agreement in the management of these patients, for example, that it is optimal to avoid hyperviscosity and iron overload, that a target Hb S level in the range of 30% is generally desirable, and that RCE as an acute treatment for pain crisis in the absence of other acute or chronic conditions is ordinarily discouraged.

Quercetin Therapy for Selected Patients with PIM1 Kinase-Positive Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma: A Pilot Study.

We reported that PIM1 kinase is expressed in the lymphocytes of patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Quercetin, a naturally occurring flavonoid, is a dietary supplement and inhibits many kinases, including PIM1, in vitro. Under an Institutional Review Board-approved protocol, we performed an open-label, single-arm pilot study to evaluate the antitumor activity of quercetin in patients with CLL/SLL. Q-ForceTM chews were administered orally, 500 mg twice daily, for 3 months. Eligible patients had failed prior therapies, had had no other standard treatment, or refused other therapies. Response was assessed based on objective change in disease parameters. Patients were included if their lymphocyte counts were rising and ≥10,000/µL but not > 100,000/µL. Three patients received quercetin treatment. There was no toxicity. Two responded with stabilization of rising lymphocyte counts (p < 0.001 for each), which remained stable during their follow-up (5 and 11 months after cessation of treatment, respectively). The CLL cells in the nonresponder harbored a TP53 mutation. Although our data from this pilot translational study are based on a small sample, further studies of quercetin as a potential therapeutic agent in selected patients with CLL/SLL appear warranted.

The management of anticoagulation in patients undergoing therapeutic plasma exchange: A concise review.

We surveyed multiple apheresis centers represented by the authors for their clinical approach to the management of anticoagulation issues during therapeutic plasma exchange (TPE). We present the results of their practices and a review of the pertinent literature. As plasma is removed during TPE, replacement with all or partial non-plasma-containing fluids (eg, 5% albumin) may lead to significant changes in hemostasis. These changes are amplified in patients who are receiving anticoagulation. We discuss various anticoagulants as well as the monitoring and adjustment of anticoagulation before, during, and after TPE. No single guideline can be applied, but rather, patients must be monitored individually, taking into account their often complex clinical conditions and medication profiles.

The ITM2B (BRI2) gene is a target of BCL6 repression: Implications for lymphomas and neurodegenerative diseases.

The human BCL6 gene encodes a transcriptional repressor that is crucial for germinal center B cell development and T follicular helper cell differentiation. It is involved in the pathogenesis of certain human lymphomas. In an effort to identify targets of BCL6 repression, we used a previously described cell system in which BCL6 repressive effects are inhibited, followed by subtractive hybridization, and identified the integral membrane 2B gene (ITM2B, formerly BRI2) as a potential target. Here we show that BCL6 can bind to its preferential consensus binding site within the first intron of ITM2B and represses its transcription. Knockdown of endogenous BCL6 in a human B cell lymphoma line increases ITM2B expression. Further, there is an inverse relationship between the expression levels of BCL6 and ITM2B proteins in 16 human B- and T-cell lymphomas studied by immunohistochemistry. Both the BCL6 and ITM2B proteins are expressed ubiquitously. Similar to some other targets of BCL6, a short form of the ITM2B protein generated by alternative splicing induces apoptosis in hematopoietic cell lines. Molecular alterations in the ITM2B gene are associated with two neurodegenerative diseases, Familial British and Familial Danish dementia. ITM2B dysfunction also may be relevant for the development of Alzheimer's disease. Our data confirm ITM2B as a target of BCL6 repression in lymphoma. A further understanding of the genes that function as regulators of the ITM2B protein may provide insights for the development of new molecular tools not only for targeted lymphoma therapy but also for the treatment of these dementias.

PIM1 gene cooperates with human BCL6 gene to promote the development of lymphomas.

Diffuse large B-cell lymphomas in humans are associated with chromosomal rearrangements (∼40%) and/or mutations disrupting autoregulation (∼16%) involving the BCL6 gene. Studies of lymphoma development in humans and mouse models have indicated that lymphomagenesis evolves through the accumulation of multiple genetic alterations. Based on our prior studies, which indicated that carcinogen-induced DNA mutations enhance the incidence of lymphomas in our mouse model expressing a human BCL6 transgene, we hypothesized that mutated genes are likely to play an important cooperative role in BCL6-associated lymphoma development. We used retroviral insertional mutagenesis in an effort to identify which genes cooperate with BCL6 in lymphomagenesis in our BCL6 transgenic mice. We identified PIM1 as the most frequently recurring cooperating gene in our murine BCL6-associated lymphomas (T- and B-cell types), and we observed elevated levels of PIM1 mRNA and protein expression in these neoplasms. Further, immunohistochemical staining, which was performed in 20 randomly selected BCL6-positive human B- and T-cell lymphomas, revealed concurrent expression of BCL6 and PIM1 in these neoplasms. As PIM1 encodes a serine/threonine kinase, PIM1 kinase inhibition may be a promising therapy for BCL6/PIM1-positive human lymphomas.

GFI1B, EVI5, MYB--additional genes that cooperate with the human BCL6 gene to promote the development of lymphomas.

The BCL6 gene, which is expressed in certain B- and T-cell human lymphomas, is involved with chromosomal rearrangements and mutations in a number of these neoplasms. Lymphomagenesis is believed to evolve through a multi-step accumulation of genetic alterations in these tumors. We used retroviral insertional mutagenesis in transgenic mice expressing the human BCL6 transgene in order to identify genes that cooperate with BCL6 during lymphomatous transformation. We previously reported PIM1 as the most frequently recurring cooperating gene in this model. We now report three newly identified cooperating genes-GFI1B, EVI5, and MYB-that we identified in the lymphomas of retroviral-injected BCL6 transgenic mice (but not in retroviral-injected non-transgenic controls); mRNA and protein expression of GFI1B and EVI5 were decreased in the murine tumors, whereas MYB mRNA and protein expression were increased or decreased. These findings correlated with protein expression in human lymphomas, both B- and T-cell. Improved therapy of lymphomas may necessitate the development of combinations of drugs that target the alterations specific to each neoplasm.

Reducing the risk of hyperammonemia from transfusion of stored red blood cells.

Ammonia concentration increases in red cell units (RBCs) during storage. We measured absolute amounts of ammonia (AA) per unit serially in stored RBCs and before and after removal of the supernatant by volume reduction (VR) or washing. Ammonia increased 6.4-fold in untreated units over 31 days. VR decreased AA 3.7-fold, whereas washing decreased it 38-fold (p<0.0001). At least for certain patients, e.g., infants receiving large volume transfusions and patients in liver failure, it may be advisable to use RBCs as fresh as possible and to limit infusion (by VR or washing) of ammonia in the supernatant.

The diagnostic value of biopsy of small peripheral lymph nodes in patients with suspected lymphoma.

In a patient with suspected lymphoma, it is considered desirable to confirm the diagnosis by excisional biopsy of enlarged lymph nodes. However, sometimes the ideal nodes are positioned internally, requiring a deep invasive procedure for access, or the patient may have underlying medical conditions that make it risky to perform such an invasive procedure. Under a protocol approved by our institution's review board (IRB), we reviewed five patients in whom superficial lymph nodes were biopsied which were smaller than usually considered optimal for diagnosis (=2 cm). In each of these cases, the biopsy yielded diagnostic information upon which treatment could be based, sparing the patient a deep invasive procedure. We suggest that in situations in which large internal lymph nodes are not easily accessible and/or the patient's clinical situation precludes more invasive procedures, including deep core needle biopsy of a large mass, it is worthwhile to consider the removal of smaller, superficial lymph nodes with minimal risk which may suffice for diagnosis.

Persistent hypocalcemia associated with therapeutic plasma exchange performed to reduce HLA antibody levels in cardiac transplant recipients.

BACKGROUND: Patients who receive heart transplants may undergo therapeutic plasma exchange to reduce high levels of HLA antibodies which may increase the risk of allograft rejection. Plasma exchange may predispose to hypocalcemia because of chelation of calcium by sodium citrate, used as an anticoagulant both during the procedure and in thawed fresh frozen plasma often used for replacement. METHODS: We report three adults with dilated cardiomyopathy who underwent cardiac transplantation and serial plasma exchange for high levels of HLA antibodies. We followed these patients' pre-exchange serum calcium levels and the quantity of calcium supplementation they received. Further, we examined myocardial tissue sections post-transplantation for calcium deposition. RESULTS: Our patients' serum calcium levels were initially normal, but, despite aggressive calcium repletion, remained low (nadirs for pre-exchange ionized calcium in two patients 4.48 and 3.8mg/dL, respectively, reference range 4.6-5.4mg/dL). For patient 3, pre-exchange total calcium on day 2 was 7.9mg/dL (reference range 8.4-10.2mg/dL). Two patients had intermittent symptoms of hypocalcemia. Studies of cardiac tissue sections (available only from these two patients) were consistent with the presence of calcium deposition post transplantation. In comparison, six patients who underwent lung transplantation and plasma exchange for high levels of HLA antibodies did not manifest significant hypocalcemia. CONCLUSIONS: We emphasize the need for prompt and sufficient calcium replacement, monitored by serum ionized calcium levels, in the early post-cardiac transplantation period when plasma exchange is performed with thawed fresh frozen plasma replacement. The persistently low serum calcium levels we observed post heart transplantation were possibly contributed to by increased myocardial calcium influx.

Adjunct therapeutic plasma exchange for anti-N-methyl-D-aspartate receptor antibody encephalitis: a case report and review of literature.

Encephalitis associated with autoantibodies directed against the N-methyl-D-aspartate receptor (NMDAR) is usually a paraneoplastic syndrome that presents in young females with ovarian teratomas. We report a case of a previously healthy 14-year-old girl with sudden-onset paranoia, hallucinations, hyperactivity, increased speech, decreased sleep, seizures, and violent behavior deteriorating to catatonia. Her cerebrospinal fluid tested positive for anti-NMDAR antibodies. She was treated with five sessions of therapeutic plasma exchange (TPE) after having failed therapy with antibiotics, intravenous steroids, intravenous immunoglobulin (IVIG), one dose of rituximab, and seven sessions of electroconvulsive therapy (ECT). The American Society for Apheresis assigns a Category III (Grade 2C) recommendation for TPE in paraneoplastic neurologic syndromes; however, apheresis specifically for anti-NMDAR encephalitis has not been well studied. Literature review revealed two case reports describing outstanding improvement in patients with anti-NMDAR encephalitis following TPE. We report no improvement in our patient's symptoms after plasma exchange and discuss possible reasons for why it failed along with review of the literature.

PDCD2, a protein whose expression is repressed by BCL6, induces apoptosis in human cells by activation of the caspase cascade.

We have previously reported that the human programmed cell death-2 gene (PDCD2), a target of BCL6 repression, is likely to be important in the pathogenesis of certain human lymphomas. We now demonstrate that transfection of a construct expressing PDCD2 induces apoptosis in human cell lines, that this occurs, at least in part, through activation of the caspase cascade, and, furthermore, that caspase inhibitors block this effect. Immunohistochemical studies in human benign lymphoid and lymphoma tissues support these findings. In addition, transfection of a VP16-BCL6 zinc fingers fusion protein, which competes with the binding of endogenous BCL6 in a Burkitt lymphoma cell line, increases PDCD2 protein expression and apoptosis, and knockdown of the PDCD2 protein in this cell line by PDCD2-specific small interfering RNA duplexes inhibits apoptosis. These studies indicate that one function of PDCD2 is to promote apoptosis in several human and mammalian cell lines and tissues, including lymphoma. Although the pathways involved in lymphomagenesis are likely to be multiple and complex, it is plausible that repression of PDCD2 expression by BCL6, which, in turn, leads to downregulation of apoptosis, is one mechanism involved in BCL6-associated lymphomatous transformation. The usefulness of increasing PDCD2 expression in the treatment of certain lymphomas merits further investigation.

Expression Pattern of the BCL6 and ITM2B Proteins in Normal Human Brains and in Alzheimer Disease.

We reported that the integral membrane 2B gene (ITM2B, also called BRI2) is a target of BCL6 repression in lymphomas. Molecular alterations in ITM2B are associated with 2 neurodegenerative diseases, Familial British and Danish dementia, and dysregulation of ITM2B function has been implicated in the pathogenesis of Alzheimer disease (AD). Although ITM2B expression has been studied, the distribution of BCL6 in human brain has not been described. Our goal is to analyze BCL6 and ITM2B localization in normal human brains and in AD by immunohistochemistry to understand their relationship. We found that, in general, they have a reciprocal relationship. BCL6 expression is present in isolated cortical neurons, granule cells in the cerebellum, scattered glial cells, and in some cells of the ependyma and choroid plexus. ITM2B is expressed in most cortical neurons, neurons of the hippocampus and dentate nucleus, cerebellar Purkinje and granule cells, and (newly described here) in focal neurons in the basal ganglia, many neurons of the thalamus and brainstem, many cells in the ependyma and choroid plexus, and in the smooth muscle of blood vessels. ITM2B expression is prominent in plaques in AD-containing dystrophic neurites but absent in neurofibrillary tangles; BCL6 expression is absent in neurofibrillary tangles and in the nuclei of cells associated with plaques in AD. It is essential to understand the localization of BCL6 and ITM2B in the brain before considering manipulation of their expression as a potential therapeutic tool.

The Relationship between RUVBL1 (Pontin, TIP49, NMP238) and BCL6 in Benign and Malignant Human Lymphoid Tissues.

The human BCL6 gene, which is involved in the pathogenesis of certain human lymphomas, encodes a transcriptional repressor that is needed for germinal center B cell development and T follicular helper cell differentiation. Our goal was to identify BCL6 target genes using a cell system in which BCL6 repressive effects are inhibited followed by subtractive hybridization, and we detected the RUVBL1 (Pontin, TIP49) gene as a potential target of BCL6 repression. Here we show that the BCL6 protein significantly represses RUVBL1 transcription (6.8-fold). Knockdown of endogenous BCL6 in a human B cell lymphoma line leads to significant upregulation of RUVBL1, and there is an inverse expression pattern between the BCL6 and RUVBL1 proteins in certain human lymphomas. RUVBL1 is part of the AAA+ superfamily and participates in multiple processes, including gene transcription regulation, chromatin remodeling, and DNA repair, which, if dysregulated, may promote lymphoma development. A further understanding of the relationship between RUVBL1 and BCL6 should improve our understanding of the pathogenesis of human lymphomas.

Thrombotic thrombocytopenic purpura and its look-alikes.

The thrombotic thrombocytopenic purpura syndrome (TTP) can be mistaken for a number of other conditions, and it is important to diagnose correctly and treat appropriately. We describe the features of TTP that can help make a positive diagnosis and other conditions in the differential diagnosis with symptoms that can overlap and mimic those of TTR. We discuss TTP and its variants, hemolytic uremic syndrome, disseminated intravascular coagulation, heparin-induced thrombocytopenia, antiphospholipid syndrome, Evans syndrome, preeclampsia/eclampsia, HELLP syndrome, acute fatty liver of pregnancy, and multiorgan failure.

Squamous cell carcinomas of the skin at ear tag sites in aged FVB/N mice.

We report the development of squamous cell carcinomas (SCCs) of the skin at or near the site of ear tags composed of a nickel-copper alloy and used for identification during the course of a long-term study of incipient congenic FVB/N mice containing the human BCL6 transgene (FVB.Cg-Tg[tetO-BCL6]Bbn Tg[EmicroSR-tTa]83Bop), their littermate controls, and wild-type FVB/N. Of a total population of 160 mice, 14 (8.8%) developed SCCs in the tagged (right) ear after a median observation period of 25 months, but none of the animals developed tumors in the opposite ear (P = 0.0001). Nine of the fourteen mice with SCCs had to be euthanized because they were thought to be in distress from the ear condition, but the remaining five died or were euthanized for other reasons related to the research study. These animals ranged in age from 331 to 921 days at the time of death. Five of the tumors were well-differentiated (grade 1) SCCs; the remainder were grade 3 and tended to be deeply invasive neoplasms with undifferentiated areas containing a spindle cell component. One of these metastasized to kidney. When using the FVB/N mouse strain for long-term studies, it is necessary to consider that nearly 9% of the population may develop SCCs at or near ear-tag sites that may necessitate early removal of the animal.

Management of lipoprotein X and its complications in a patient with primary sclerosing cholangitis.

Lipoprotein X (LpX) is an abnormal lipoprotein found in conditions such as lecithin:cholesterol acyltransferase deficiency and cholestatic states (e.g., primary biliary cirrhosis and primary sclerosing cholangitis). Management of severe hypercholesterolemia due to LpX with drugs and physical removal methods is not well established in the literature. A case is discussed of a 51-year-old woman who presented with multiple electrolyte abnormalities, xanthomas and neuropathy found to be secondary to LpX in the setting of primary sclerosing cholangitis. This case highlights that oral medications, including statins, may be insufficient to normalize lipid levels or improve clinical symptoms of LpX and presents therapeutic plasma exchange as a safe and effective therapeutic option to treat the morbid sequela of LpX hyperlipidemia.