CD23+ mantle cell lymphoma: a clinical pathologic entity associated with superior outcome compared with CD23- disease

Mantle cell lymphoma (MCL) commonly lacks expression of CD23. However, a significant minority of MCLs express CD23, as assessed by flow cytometric immunophenotyping (FCIP). The aims of our study were to investigate the expression of CD23 by FCIP in patients with MCL and to correlate CD23 expression with pathologic and clinical parameters, including outcome. We studied 53 patients with untreated MCL who had CD23 expression determined by FCIP. At diagnosis, 14 MCLs (26%) were CD23+ at all tissue sites, whereas 33 (62%) were CD23-, and 6 (11%) had discordant CD23 expression among different tissue sites. Patients with CD23- MCL had extranodal disease more commonly compared with patients with CD23+ MCL. Moreover, with 57-month median follow-up, the 4-year event-free and overall survival rates for CD23+ MCL were 45% and 75%, respectively, compared with 19% and 51% for CD23- MCL. In multivariate Cox regression analysis, CD23 status and leukemic-phase MCL were the most important factors predicting outcome.

Hypoxia inducible factor-alpha activation in lymphoma and relationship to the thioredoxin family

Hypoxia inducible factors (HIFs) activate oncogenic pathways, while thioredoxins (Trx), including Trx1 and Trx reductases-1 and -2 (TrxR1 and TrxR2), promote HIF-alpha stabilization. In immunoblotting studies in lymphoma cell lines we found that Raji and SUDHL4 cells exhibited normoxic HIF-2alpha protein stabilization. Five cell lines showed increased TrxR1 expression, while only Namalwa, HF1 and SUDHL4 had Trx1 and TrxR2 activation. Tissue microarrays in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) identified different HIF expression among histological subgroups (e.g. 44% DLBCL vs. 11% of FL cases with moderate-to-high expression of HIF-1alpha and HIF-2alpha, P = 0.0017). These data demonstrate that HIF and the thioredoxin family are abnormally activated in lymphoma.

Dietary factors and risk of t(14;18)-defined subgroups of non-Hodgkin lymphoma

OBJECTIVE

To evaluate the associations between diet and non-Hodgkin lymphoma (NHL) according to t(14;18) status, one of the most common chromosomal abnormalities in NHL, as t(14;18)-positive NHL represents a genetically more homogeneous group than NHL overall.

METHODS

We determined the presence of the t(14;18)(q32;q21) by fluorescence in situ hybridization in 172 of 175 tumor blocks from a population-based, case-control study conducted in Nebraska during 1983-1986. Information on the frequency of consumption as an adult of 30 food items was derived from the parent case-control study. Dietary factors in 60 t(14;18)-positive and 87 t(14;18)-negative cases were compared with 1,075 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using polytomous logistic regression.

RESULTS

The risk of t(14;18)-positive NHL for the highest versus the lowest approximate tertile of intake was elevated for milk (OR = 2.2; 1.0-5.0) and dietary nitrite (OR = 2.8; 1.3-6.1), whereas coffee consumption was inversely associated with risk (OR = 0.4; 0.2-0.7). We also found inverse associations between the intake of fish (OR = 0.5; 0.3-1.0) and carotene (OR = 0.5; 0.2-0.9) and risk of t(14;18)-negative NHL. There was no association between the intake of meats, vegetables, protein, or vitamin C and risk of either t(14;18)-positive or t(14;18)-negative NHL.

CONCLUSION

We observed differences in associations between diet and t(14;18)-defined subgroups of NHL. These findings should be interpreted cautiously because of the small sample.

Sustained hematologic and central nervous system remission with single-agent denileukin diftitox in refractory adult T-cell leukemia/lymphoma

Human T-lymphotrophic virus-1-associated adult T-cell leukemia/lymphoma (ATLL) is a rare and often fatal disease. Initial treatment often includes zidovudine/interferon (IFN)-based therapy, although disease remission is typically not complete or durable. This study reports on a 55-year-old man with relapsed/refractory leukemic-phase ATLL including significant central nervous system (CNS) disease with resistance to previous zidovudine/IFN and arsenic trioxide/IFN treatment. The patient experienced a rapid hematologic and CNS clinical response with single-agent denileukin diftitox therapy (18 microg/kg per day for 5 days). He tolerated 8 cycles of denileukin diftitox therapy well and experienced a sustained complete hematologic and CNS remission. The patient subsequently underwent matched sibling reduced-intensity allogeneic transplantation and remains disease free. Further study examining denileukin diftitox in patients with relapsed/refractory ATLL is warranted.

Sun exposure and non-Hodgkin lymphoma: a population-based, case-control study

To investigate the association between sun exposure and risk of non-Hodgkin lymphoma (NHL) by histologic subtypes and to explore whether or not vitamin D intake modify sun-NHL association, we analysed data from a population-based, case-control study conducted in Nebraska between 1999 and 2002. Information on sun exposure during the spring, summer, fall and winter was collected from 387 cases and 535 controls by telephone interview. We found no association between seasonal sun exposure and risk of NHL. Vitamin D intake was also not associated with NHL risk, nor does it modify the sun-NHL association. In contrast, total hours of sun exposure was inversely associated with the risk of NHL (odds ratio (OR)=0.7 comparing >30h/week to <14h/week, 95% confidence interval (CI)=0.5-1.1). Sun exposure was associated with a lower risk of NHL among farmers (OR=0.8, 0.5-1.3 for 14-30h/week; OR=0.6, 0.3-0.9 for >30h/week; p-trend=0.02), but not among non-farmers. Total hours of sun exposure was also inversely associated with risk of diffuse large B-cell lymphoma and T-cell lymphoma. In conclusion, our data suggest that total hours of sun exposure is associated with a lower risk of NHL, and the inverse association is not modified by vitamin D intake, is stronger among farmer, and may vary by subtypes.

Granulocyte-colony stimulating factor administration to healthy individuals and persons with chronic neutropenia or cancer: an overview of safety considerations from the Research on Adverse Drug Events and Reports project

Granulocyte-colony stimulating factor (G-CSF) is widely administered to donors who provide peripheral blood stem cells (PBSC) for individuals who undergo hematopoietic stem cell transplants. Questions have been raised about the safety of G-CSF in this setting. Herein, the Research on Adverse Drug Events and Reports (RADAR) project investigators reviewed the literature on G-CSF-associated adverse events in healthy individuals or persons with chronic neutropenia or cancer. Toxicities identified included bone pain and rare instances of splenic rupture, allergic reactions, flares of underlying autoimmune disorders, lung injury and vascular events. Among healthy individuals, four patients developed splenic rupture shortly after G-CSF administration and three patients developed acute myeloid leukemia 1 to 5 years after G-CSF administration. Registry studies identified no increased risks of malignancy among healthy individuals who received G-CSF before PBSC harvesting. However, more than 2000 donors would have to be followed for 10 years to detect a 10-fold increase in leukemia risk. Our review identifies bone pain as the most common toxicity of G-CSF administration. There are questions about a causal relationship between G-CSF administration and acute leukemia, but more long-term safety data from database registries are needed to adequately evaluate such a relationship.

Obesity and risk of non-Hodgkin lymphoma (United States)

OBJECTIVE

Few studies have explored the potential association between body mass index (BMI) and non-Hodgkin lymphoma (NHL) according to histologic subtypes, or have evaluated BMI at different periods in the subject's life, and the results of these studies have been inconsistent.

SUBJECTS

A population-based, case-control study of 387 patients with NHL and 535 controls conducted in Nebraska between 1999 and 2002.

METHODS

Information on usual adult weight, weight at the ages 20-29, 40-49, and 60-69 years, height, physical activity, and other lifestyle factors was collected by telephone interview. A self-administered semi-quantitative food frequency questionnaire was used to collect dietary intake. Risk was estimated by odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for age, total energy intake, physical activity, and other confounding factors.

RESULTS

Higher adult BMI was associated with risk of NHL (OR=1.4; 95% CI=0.9-2.0) comparing the obese group (BMI >or= 30.0 kg/m(2)) with the normal weight group (BMI=18.5-24.9 kg/m(2)). The risk was higher for those who were class 2 obese (BMI >or= 35.0 kg/m(2), OR=1.7; 95% CI=1.0-2.9). The positive association was similar among men and women. An excess risk of NHL was associated with high BMI at ages 40-49 years (OR=1.6; 95% CI=1.0-2.5), and to a lesser extent, at ages 20-29 years (OR=1.4; 95% CI=0.8-2.5). Obesity at ages 40-49 years was also associated with a higher risk of small lymphocytic lymphoma (OR=4.5; 95% CI=1.5-13.3), diffuse large B-cell NHL (OR=1.8; 95% CI=0.9-3.9) and follicular NHL (OR=1.8; 95% CI=0.9-3.5).

CONCLUSION

Obesity is associated with risk of NHL overall. Obesity at ages 40-49 years is also associated with a higher risk of NHL overall, and particularly small lymphocytic, follicular, and diffuse large B-cell NHL.

G-CSF is not necessary to maintain over 99% dose-intensity with ABVD in the treatment of Hodgkin lymphoma: low toxicity and excellent outcomes in a 10-year analysis

Dose-intensity of chemotherapy is important in the treatment of Hodgkin lymphoma (HL) and granulocyte-colony stimulating factor (G-CSF) is commonly used to maintain it. We reviewed all newly diagnosed HL patients who were treated at our institution between 1996 and 2005. Fifty-nine patients received adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD) chemotherapy with no dose reductions, treatment delays, and without G-CSF, regardless of absolute neutrophil count (ANC). The median ANC on all ABVD treatment days (n = 658) was 0.925 x 10(9)/l, and was <0.5 x 10(9)/l on 26% of treatment days. Median normalised ABVD dose-intensity was 99.1% (range, 93-100%) and median cycle duration was 28.2 d. Incidence of bleomycin lung toxicity was 1.6%, 0.44% treatments were complicated by febrile neutropenia, and no secondary malignancies have occurred (median follow-up 48 months; range, 11-130 months). Five-year event-free (EFS) and overall survival (OS) were 92.9% and 97.4% respectively. Furthermore, the 5-year EFS and OS (87.4% and 94.1% respectively) for advanced stage patients compared favourably with a similar ABVD patient group who received routine prophylactic G-CSF (n = 23) with EFS 80.0% and OS 91.3% (P = 0.46 and 0.67 respectively). Our experience suggests that ABVD may be safely and effectively administered at >99% dose-intensity without G-CSF support, regardless of the ANC.

Phase I/II trial of total lymphoid irradiation and high-dose chemotherapy with autologous stem-cell transplantation for relapsed and refractory Hodgkin's lymphoma

BACKGROUND

The standard approach to treatment of relapsed/refractory Hodgkin's lymphoma (HL) is high-dose chemotherapy conditioning followed by autologous hematopoietic stem-cell transplantation (aHSCT). We report the results of a prospective phase I/II clinical trial of accelerated hyperfractionated total lymphoid irradiation (TLI) immediately followed by high-dose chemotherapy for relapsed/refractory HL.

PATIENTS AND METHODS

Forty-eight patients underwent aHSCT with either sequential TLI/chemotherapy (n = 32) or chemotherapy-alone conditioning (n = 16), based on prior radiation exposure. The first 22 patients enrolled on trial received escalating doses of etoposide (1600-2100 mg/m(2)) with high-dose carboplatin and cyclophosphamide.

RESULTS

No dose-limiting toxicity was seen and TLI/chemotherapy was well tolerated. The 5-year event-free survival (EFS) estimate for all patients was 44% with overall survival (OS) of 48%. Five-year EFS and OS for the TLI/chemotherapy group was 63% and 61%, respectively, compared with 6% and 27%, respectively, for the chemotherapy-alone group (P < 0.0001 and P = 0.04, respectively). Patients with primary induction failure HL who received TLI/chemotherapy had 5-year EFS and OS rate of 83%. The 100-day treatment-related mortality was 4.2% and two secondary cancers were seen. Significant factors predicting survival by multivariate analysis included TLI/chemotherapy conditioning and B symptoms at relapse.

CONCLUSIONS

Sequential TLI/chemotherapy conditioning for relapsed/refractory HL is safe and associated with excellent long-term survival rates.

Targeting angiogenesis for the treatment of sarcoma

PURPOSE OF REVIEW

More therapeutic options are needed for bone and soft tissue sarcomas, especially for patients with metastatic disease. Recent randomized clinical trials conducted in colon, breast and lung cancer have shown the anti-vascular endothelial growth factor agent, bevacizumab, alone or in combination with chemotherapy, improves response and survival. Preclinical studies have demonstrated the anti-tumor effects of varied anti-angiogenic agents in sarcoma cell lines and tumor models.

RECENT FINDINGS

Preclinical studies in sarcomas have evaluated the role of targeted agents including platelet-derived growth factor, matrix metalloproteinases, urokinase receptor and varied small-molecule tyrosine kinase inhibitors. Novel angiogenesis inhibitors are being studied in the treatment of sarcoma, including monoclonal antibodies against vascular endothelial growth factor, cis- and trans-retinoic acids, thalidomide, and tyrosine kinase inhibitors. Phase I, II and III clinical trials continue to evaluate these agents alone, in combinations together and combined with standard chemotherapy. We review herein the preclinical rationale and clinical trial results of anti-angiogenesis therapy in the treatment of soft tissue and bone sarcoma.

SUMMARY

Preclinical mechanistic study and clinical trials are continuing in order to evaluate the therapeutic role and ultimately validate the efficacy of the varied anti-angiogenesis agents in soft tissue and bone sarcoma.

Haematological malignancies developing in previously healthy individuals who received haematopoietic growth factors: report from the Research on Adverse Drug Events and Reports (RADAR) project

Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) and granulocyte colony-stimulating factor (G-CSF) promote haematopoietic progenitor cell maturation. We reviewed the findings for healthy volunteers/donors who developed haematological malignancies following PEG-rHuMGDF or G-CSF administration. Information was reviewed for three of 538 volunteers who received PEG-rHuMGDF in clinical trials and two of 200 donors who underwent G-CSF mobilised stem cell harvesting procedures for sibling stem cell transplants. Mantle cell, diffuse large B-cell lymphoma and chronic lymphocytic leukaemia were diagnosed 1-5 years after PEG-rHuMGDF exposure among three volunteers. For one patient, thrombocytopenia due to autoantibodies to PEG-rHuMGDF developed shortly after PEG-rHuMGDF administration and persisted until chemotherapy was administered. All three achieved complete remission, although one patient relapsed. Acute myeloid leukaemia was diagnosed 4 and 5 years after G-CSF mobilisation in two donors who underwent peripheral blood stem cell donation for sibling allogeneic haematopoietic stem cell transplantation. Following intensive chemotherapy, one died from acute leukaemia and the second is in complete remission. Controversy exists over the appropriateness of administering haematopoietic growth factors to healthy individuals. While a causal relationship with haematological malignancies cannot be demonstrated, long-term follow-up among healthy individuals who receive haematopoietic growth factors is needed.

Gemtuzumab ozogamicin-associated sinusoidal obstructive syndrome (SOS): an overview from the research on adverse drug events and reports (RADAR) project

Gemtuzumab ozogamicin (GO) was approved for marketing in 2000 by the United States Food and Drug Administration (FDA) for older patients with relapsed acute myeloid leukemia (AML). Four months later, 14 phase II clinical trial participants who received novel GO-containing combination chemotherapy regimens developed an unexpected hepatic toxicity termed sinusoidal obstructive syndrome (SOS) or hepatic veno-occlusive disease (VOD). Investigators associated with the Research on Adverse Drug Events and Reports (RADAR) project reviewed safety reports for GO included in reports of clinical trials and observational studies, interim reports from an FDA mandated Prospective Observational Registry, and the Food and Drug Administration's Adverse Event Reporting System. Medline searches provided incidence estimates of GO-associated SOS and comparative rates of SOS without GO. SOS is characterized by hyperbilirubinemia, painful hepatomegaly, ascites, and sudden weight gain developing at a median of 10 days following GO administration for patients who did not undergo an allogeneic SCT procedure and 13 days following an allogeneic SCT for patients who had previously received GO. Among adult AML patients who received GO in clinical trials, SOS incidence was 3% at doses < or =6 mg/m(2) if administered as monotherapy or in combination with non-hepatotoxic agents versus 28% if administered with thioguanine and 15% when administered as monotherapy at a dose of 9 mg/m(2). Observational studies identified SOS rates between 15% and 40% if an SCT is performed within 3 months of GO administration. The FDA mandated Prospective Observational Registry of patients who receive care at 60 medical centers has identified GO-associated SOS rates of 14% if an SCT is performed and 9% otherwise. Caution is advised when administering GO in routine clinical practice, particularly if administered with other hepatotoxic agents, at doses and schedules more intensive than those approved by the FDA, or within 3 months of a SCT procedure.

Does younger donor age affect the outcome of reduced-intensity allogeneic hematopoietic stem cell transplantation for hematologic malignancies beneficially?

Sixty three patients aged 27-66 years (median 52) were allografted from HLA-matched sibling (n=47), 10 of 10 allele-matched unrelated (n=19), or one-antigen/allele-mismatched (n=7) donors aged 24-69 years (median 46) after a conditioning regimen comprising 100 mg/m(2) melphalan. Cyclophosphamide (50 mg/kg) was also administered to patients who had not been autografted previously. Cyclosporine or tacrolimus, and mycophenolate mofetil were administered to prevent graft-versus-host disease (GVHD). The 2-year cumulative incidences of relapse and TRM were 55 and 24% respectively, and 2-year probabilities of overall survival (OS) and disease-free survival (DFS) were 36 and 21%, respectively. Poor performance status, donor age >45 years and elevated lactate dehydrogenase (LDH) increased the risk of treatment-related mortality (TRM), refractory disease and donor age >45 years increased the risk of relapse, and OS and DFS were adversely influenced by refractory disease, poor performance status, increased LDH, and donor age >45 years. Our data suggest that younger donor age is associated with better outcome after sub-myeloablative allogeneic hematopoietic stem cell transplantation (HSCT) for hematologic malignancies due to lower TRM and relapse. This finding raises the question of whether a young 10-allele-matched unrelated donor is superior to an older matched sibling donor in patients where the clinical situation permits a choice between such donors.

Ideal rather than actual body weight should be used to calculate cell dose in allogeneic hematopoietic stem cell transplantation

Whether the CD34+ and CD3+ cell doses in allogeneic HSCT should be estimated using actual (ABW) or ideal (IBW) body weight has never been definitively determined. We have shown that CD34+ cell doses based upon IBW are better predictive of engraftment after autologous and allogeneic HSCT. Sixty-three patients undergoing reduced-intensity HSCT after a uniform preparative regimen were evaluated to determine the effect of cell dose. ABW and IBW were 45-147 kg (median 79) and 52-85 kg (median 67) respectively. The ABW-IBW difference was -24% to +133% (median +16%); nine patients were >5% underweight and 41 were >5% overweight. The CD34+ cell dose (10(6)/kg) was 1.4-11.8 (median 5) by IBW and 1.2-9.3 (median 4.5) by ABW. The CD3+ cell dose (10(8)/kg) was 0.9-14.9 (median 3) by IBW and 0.7-19.7 (median 2.7) by ABW. While CD34+ and CD3+ cell doses based upon IBW were found to affect transplant-related mortality, and disease-free and overall survival significantly, those based on ABW were either not predictive of outcome or the differences were of borderline significance. We suggest using IBW rather than ABW to calculate cell doses for HSCT; for statistical analyses and for clinical practice if a specific cell dose is being targeted.

Oxidative stress and apoptosis: a new treatment paradigm in cancer

Redox regulation has been shown to be an important component of malignant cell survival. Tipping the cellular redox balance through pharmacologic regulation in favor of increasing intracellular reactive oxygen species (ROS) and/or depleting protective reducing metabolites (such as glutathione and nicotinamide adenine dinucleotide phosphate) may lead to oxidative stress and resultant induction of apoptosis for the treatment of cancer. We review the biology and importance of ROS with regard to malignant and normal cells. Moreover, we discuss pre-clinical and clinical data regarding novel therapeutic agents that modulate the cellular redox system including buthionine sulfoximine, ascorbic acid, arsenic trioxide, imexon, and motexafin gadolinium as single-agents and in combination. Continued research is needed to better understand the mechanisms and specific apoptotic pathways involved in ROS-induced cell death, as well as, to determine the most rationale and effective combination of redox-active agents.

T-cell non-Hodgkin lymphoma

T-cell non-Hodgkin lymphomas (NHLs) are uncommon malignancies. The current WHO/EORTC classification recognizes 9 distinct clinicopathologic peripheral T-cell NHLs. These disorders have unique characteristics and require individualized diagnostic and therapeutic strategies. Tremendous progress has been made in recent years in the understanding of the pathogenesis of these disorders. Specific chromosomal translocations and viral infections are now known to be associated with certain lymphomas. In this review, we describe their clinical and pathologic features. We also discuss the use of molecular studies in the diagnostic work-up of T-cell lymphomas. Because of the rarity of these disorders and the lack of well-designed clinical trials, the treatment of peripheral T-cell NHLs is often challenging. Additional studies are required to learn more about the biology of these diseases, which may lead to more optimal and possibly targeted therapies.

Epoetin-induced pure red-cell aplasia (PRCA): preliminary results from the research on adverse drug events and reports (RADAR) group

In 2002, investigators from France reported 13 patients in whom pure red cell aplasia developed during treatment with recombinant human erythropoietin (epoetin). We reviewed 208 cases of this syndrome reported worldwide. Adverse event reports describing suspected and confirmed cases of epoetin-associated PRCA in websites maintained by the manufacturers and distributors of epoetin products and other publicly available sources were reviewed. Cases were reported from countries in Europe, North America, Asia, Australia and the United States (US). For >95% of the cases, EPREX had been administered subcutaneous to persons with chronic kidney disease (CKD) and anemia for a mean of nine months prior to diagnosis of PRCA. For 80% of persons with the syndrome, reversal of antibody production and recovery of reticulocytes occurred with discontinuation of epoetin and treatment with immunosuppressive agents. Patients with anemia of CKD who developed neutralizing anti-erythropoietin antibodies and pure red cell aplasia during treatment with epoetin have been identified in a number of countries. In non-US countries, switching renal dialysis patients from subcutaneous to intravenous administration of epoetin alpha and improved handling of the drug appear to have been successful strategies for reducing the occurrence of this toxicity. The decrease in cases occurred coincident with these varied changes, although it is difficult to prove causality. PRCA is a rare, but important side effect of epoetin therapy.

Clinical characteristics of erythropoietin-associated pure red cell aplasia

Recombinant human erythropoietin (epoetin) was first used for the treatment of anemia resulting from renal disease in 1986. During the first 10 years of its use, there were only three cases of epoetin-induced antibodies reported, which resulted in pure red cell aplasia (PRCA). Between 1998 and 2002, 191 chronic kidney disease patients developed PRCA during the course of epoetin treatment. Clinical characteristics of patients with PRCA include an absolute resistance to epoetin therapy, with a rapid development of severe anemia and very low reticulocyte count. In addition, patients developed high titre, high affinity neutralizing antibodies, which are detectable by immunoassays. The diagnosis of PRCA requires the onset of severe anemia, erythropoietin neutralizing antibodies in circulation, the lack of red cell precursors in the bone marrow aspirate, and normal to elevated transferrin saturation. Patients require blood transfusions to maintain an acceptable level of hemoglobin. Cessation of epoetin treatment alone does not improve PRCA. Patients have required immunosuppressive treatment. However, the most efficacious treatment has been kidney transplantation accompanied by immunosuppressive agents that prevent organ rejection. Evaluating patients receiving recombinant epeoetin therapy who experience a sudden loss of epoetin efficacy for the possibility of antibody-mediated PRCA is crucial. Timely identification and treatment of this rare syndrome can prevent the development of severe red blood cell transfusion requirements and the potential complications of iron overload, which results from these transfusions.

Long-term outcome of individuals with pure red cell aplasia and antierythropoietin antibodies in patients treated with recombinant epoetin: a follow-up report from the Research on Adverse Drug Events and Reports (RADAR) Project

Since its introduction in 1988, recombinant human erythropoietin (epoetin) has been standard treatment for patients with anemia due to chronic kidney disease. From 1998 to 2004, nearly 200 epoetin-treated persons with chronic kidney disease developed antibodies to epoetin, resulting in pure red cell aplasia (PRCA). The majority of these patients received Eprex, an epoetin alfa product marketed exclusively outside the United States. Herein, we report on the long-term outcome of these individuals. For 170 chronic kidney disease patients who developed epoetin-associated PRCA and had 3 months or more follow-up information available, case reports from the Food and Drug Administration and epoetin manufacturers were reviewed for information on clinical characteristics of the patients, immunosuppressive treatments, epoetin responsiveness, and hematologic recovery. Overall, 64% of the PRCA patients received immunosuppressive therapy, including 19 who also underwent a renal transplantation. Thirty-seven percent experienced a hematologic recovery, with higher hematologic recovery rates among PRCA patients who received immunosuppressive therapy (57% vs 2%, P < .001). Among 34 patients who received epoetin after the onset of PRCA, 56% regained epoetin responsiveness. The highest rates of epoetin responsiveness were observed among persons whose antierythropoietin antibodies were undetectable when epoetin was administered (89%). Among chronic kidney disease patients with epoetin-associated PRCA, epoetin discontinuation and immunosuppressive therapy or renal transplantation is necessary for hematologic recovery. Reinitiation of epoetin therapy among individuals could be considered if antierythropoietin antibodies are undetectable.