X-linked lymphoproliferative disease. 2B4 molecules displaying inhibitory rather than activating function are responsible for the inability of natural killer cells to kill Epstein-Barr virus-infected cells

2B4 is a surface molecule involved in activation of the natural killer (NK) cell-mediated cytotoxicity. It binds a protein termed Src homology 2 domain-containing protein (SH2D1A) or signaling lymphocyte activation molecule (SLAM)-associated protein (SAP), which in turn has been proposed to function as a regulator of the 2B4-associated signal transduction pathway. In this study, we analyzed patients with X-linked lymphoproliferative disease (XLP), a severe inherited immunodeficiency characterized by critical mutations in the SH2D1A gene and by the inability to control Epstein-Barr virus (EBV) infections. We show that, in these patients, 2B4 not only fails to transduce triggering signals, but also mediates a sharp inhibition of the NK-mediated cytolysis. Other receptors involved in NK cell triggering, including CD16, NKp46, NKp44, and NKp30, displayed a normal functional capability. However, their activating function was inhibited upon engagement of 2B4 molecules. CD48, the natural ligand of 2B4, is highly expressed on the surface of EBV(+) B cell lines. Remarkably, NK cells from XLP patients could not kill EBV(+) B cell lines. This failure was found to be the consequence of inhibitory signals generated by the interaction between 2B4 and CD48, as the antibody-mediated disruption of the 2B4-CD48 interaction restored lysis of EBV(+) target cells lacking human histocompatibility leukocyte antigen (HLA) class I molecules. In the case of autologous or allogeneic (HLA class I(+)) EBV(+) lymphoblastoid cell lines, restoration of lysis was achieved only by the simultaneous disruption of 2B4-CD48 and NK receptor-HLA class I interactions. Molecular analysis revealed that 2B4 molecules isolated from either XLP or normal NK cells were identical. As expected, in XLP-NK cells, 2B4 did not associate with SH2D1A, whereas similar to 2B4 molecules isolated from normal NK cells, it did associate with Src homology 2 domain-containing phosphatase 1.

Efficacy and safety of rituximab in B-cell post-transplantation lymphoproliferative disorders: results of a prospective multicenter phase 2 study

B-cell posttransplantation lymphoproliferative disorder (B-PTLD) is a rare but severe complication of transplantation, with no consensus on best treatment practice. This prospective trial, the first to test a treatment for PTLD, was designed to evaluate the efficacy and safety of rituximab in patients with B-PTLD after solid organ transplantation (SOT). Forty-six patients were included and 43 patients were analyzed. Patients were eligible if they had untreated B-PTLD that was not responding to tapering of immunosuppression. Treatment consisted of 4 weekly injections of rituximab at 375 mg/m2. At day (d) 80, 37 (86%) patients were alive, and the response rate was 44.2%, including 12 complete response/unconfirmed complete response (CR/CRu). The only factor predictive of a response at d80 was a normal lactate dehydrogenase level (P = .007, odds ratio [OR] = 6.9). At d360, responses were maintained in 68% of patients, and 56% of patients were alive. The overall survival rate at 1 year was 67%. We conclude that rituximab is effective and safe in PTLD, with stable responses at 1 year. The response rate and overall survival might be improved by combining rituximab with other treatments.

Establishment of complete and mixed donor chimerism after allogeneic lymphohematopoietic transplantation: recommendations from a workshop at the 2001 Tandem Meetings of the International Bone Marrow Transplant Registry and the American Society of Blood and Marrow Transplantation

Approaches to the measurement of lymphohematopoietic chimerism have evolved from laboratory research to important clinical tools. However, there has been no logical, consistent, and uniform set of recommendations for the measurement of chimerism in clinical transplantation. The National Marrow Donor Program and the International Bone Marrow Transplant Registry (IBMTR) sponsored a workshop to discuss the use of chimerism analysis after allogeneic transplantation. The workshop was organized in an effort to make reasonable recommendations regarding laboratory techniques, the types of specimens to be studied, and the frequency of analysis. The panel recommended the following guidelines: 1. Chimerism analysis should use sensitive, informative techniques. At present, short tandem repeats (STR) or variable number tandem repeats (VNTR) analysis is the approach most likely to give reproducible informative data. 2. Peripheral blood cells are generally more useful than bone marrow cells for chimerism analysis. 3. Lineage-specific chimerism should be considered the assay of choice in the setting of nonmyeloablative and reduced-intensity conditioning. 4. The use of T-cell depletion, nonmyeloablative or reduced-intensity conditioning, or novel graft-versus-host disease (GVHD) prophylactic regimens warrants chimerism analysis at 1, 3, 6, and 12 months, because interventions such as donor lymphocyte infusions may depend on chimerism status. 5. In nonmyeloablative transplantation, the early patterns of chimerism may predict either GVHD or graft loss. Therefore, more frequent (every 2-4 weeks) peripheral blood analysis may be warranted. 6. For nonmalignant disorders, chimerism generally should be measured 1, 2, and 3 months after transplantation. Interventions to enhance donor engraftment must be considered on a disease-specific basis in relation to concurrent GVHD and, ultimately, clinical rationale.

Mortality and causes of death in primary Sjögren's syndrome: A prospective cohort study

OBJECTIVE

This study was undertaken to analyze standardized mortality ratios (SMRs) and causes and predictors of death in primary Sjögren's syndrome (SS) diagnosed according to 3 different classification criteria sets (the Copenhagen criteria, the European criteria, and the American-European consensus criteria (AECC).

METHODS

A linked registry study using information from the Malmö Primary SS Registry combined with the Swedish Cause-of-Death Registry was performed, and SMRs were calculated. Kaplan-Meier survival curves and log rank tests were used to compare survival probability between subgroups of patients with primary SS. Cox regression analysis was used to study the predictive value of various laboratory findings at the time of diagnosis.

RESULTS

Four hundred eighty-four patients with a median followup of 7 years (range 1 month to 17 years 11 months) were included. The SMR for those fulfilling the AECC (n = 265) was 1.17 (95% confidence interval [95% CI] 0.81-1.63). Thirty-four deaths occurred in this group of patients. Excess mortality was found only for lymphoproliferative malignancy (cause-specific SMR 7.89 [95% CI 2.89-17.18]), corresponding to 2.53 excess deaths per 1,000 person-years at risk. In those not fulfilling the AECC (n = 219), 14 deaths occurred, the SMR was 0.71 (95% CI 0.39-1.20), and no excess mortality due to any specific cause was found. Hypocomplementemia, defined as C3 and/or C4 values in the lowest quartile of the SS patients' values at the time of diagnosis, was a significant predictor of death, mainly due to lymphoproliferative malignancy.

CONCLUSION

No increased all-cause mortality could be detected for patients with primary SS compared with the general population. When subgroups of primary SS were compared, excess mortality due to lymphoproliferative malignancy was found in patients fulfilling the AECC, the strongest predictor for unfavorable outcome being low C3 and/or C4 levels at the time of diagnosis.

Early identification of Epstein-Barr virus-associated post-transplantation lymphoproliferative disease

Epstein-Barr virus-associated lymphoproliferative disease (EBV-LPD) is a common, usually fatal, complication developing after transplantation of bone marrow from HLA-mismatched or HLA-matched unrelated donors. Prompted by recent reports of successful treatment of EBV-LPD, we investigated methods which could result in early identification of patients at high risk for this disorder, thus improving the likelihood of successful therapeutic interventions. Both the outgrowth of transformed B lymphocytes ex vivo (100% correlation) and the detection of EBV DNA by a PCR method (80% correlation) showed statistically significant association with the histopathological diagnosis of EBV-LPD. Because these abnormalities can be detected prior to the onset of clinical disease. It should now be possible to use a combination of the methods described here to identify patients at high risk of developing EBV-LPD, thus enabling early therapeutic intervention.

Complement-mediated cell death induced by rituximab in B-cell lymphoproliferative disorders is mediated in vitro by a caspase-independent mechanism involving the generation of reactive oxygen species

Mechanisms involving the in vitro effect of rituximab in cells from 55 patients with B-cell lymphoproliferative disorders were investigated. No cytotoxic effect was observed when cells were incubated with rituximab alone, but in the presence of human AB serum rituximab induced complement-dependent cell death (R-CDC). A cytotoxic effect was observed in cells from 9 of 33 patients with B-cell chronic lymphocytic leukemia, 16 of 16 patients with mantle-cell lymphoma, 4 of 4 patients with follicular lymphoma, and 2 of 2 patients with hairy-cell leukemia. R-CDC was observed in cells from patients expressing more than 50 x 10(3) CD20 molecules per cell, and directly correlated with the number of CD20 molecules per cell. Preincubation with anti-CD59 increased the cytotoxic effect of rituximab and sensitized cells from nonsensitive cases. Neither cleavage of poly-ADP ribose polymerase (PARP) nor activation of caspase-3 was observed in R-CDC. In addition, no cells with a hypodiploid DNA content were detected and R-CDC was not prevented by a broad-spectrum caspase inhibitor, suggesting a caspase-independent mechanism. Incubation with rituximab in the presence of AB serum induced a rapid and intense production of reactive oxygen species (ROS). R-CDC was blocked by the incubation of cells with N-acetyl-L-cysteine (NAC) or Tiron, 2 ROS scavengers, indicating that the cytotoxic effect was due to the generation of superoxide (O) radicals. In conclusion, the results of the present study suggest that CD20, CD59, and complement have a role in the in vitro cytotoxic effect of rituximab, which is mediated by a caspase-independent process that involves ROS generation.

Absence of CD26 expression is a useful marker for diagnosis of T-cell lymphoma in peripheral blood

We report flow cytometric characterization of surface CD26 expression in 271 peripheral blood samples from 154 patients evaluated for the presence of a T-cell lymphoproliferative disorder, primarily mycosis fungoides/Sézary syndrome (MF/SS). The presence of morphologically identifiable tumor cells on peripheral blood smears was the criterion for lymphomatous involvement. In 66 of 69 samples from 28 patients, we identified an abnormal CD26-/dim T-cell population that was distinct from the variable CD26 expression seen in normal peripheral blood T cells. This population was CD26- in 23 patients and weakly CD26+ in 5 patients. CD7 was more variably expressed in MF/SS tumor cells, allowing recognition of a distinct, quantifiable abnormal T-cell population in only 34 of 69 involved samples. An increased CD4/CD8 ratio and lower surface expression of CD4 in tumor cells also helped separate the CD26-/dim atypical population for quantification. In 35 blood samples from other types of T-cell tumors, tumor cells in 10 of 11 morphologically involved cases showed absent/dim CD26. Although capable of detecting abnormalities in most cases of MF/SS, CD7 expression does not provide as clear a separation of the neoplastic population and can be replaced by CD26 staining in routine peripheral blood flow cytometric screening of MF/SS patients.

EDTA-dependent pseudothrombocytopenia: a clinical and epidemiological study of 112 cases, with 10-year follow-up

In the past 10 years, we have observed 112 cases of EDTA-dependent pseudothrombocytopenia (PTCP) due to in vitro platelet clumping at room temperature. 93 patients had antiplatelet antibodies (48 IgM, 30 IgG, 3 IgA, and 12 had two different isotypes concomitantly). In 20% of patients, the presence of IgM antibodies characteristically accompanied platelet agglutination also at 37 degrees C, and in citrated blood. The phenomenon was not age or sex related, nor was it associated with any particular pathology or use of specific drugs, and was present in both healthy subjects and patients with various diseases. Flow cytofluorimetric analysis of CD5-positive B cells, which are responsible for autoantibody production, did not demonstrate any changes in the percentage and absolute number of this lymphocyte subset. Average follow-up was 5 years (6 months-10 years); however, previous clinical records disclosed that PTCP was present for more than 15 years in four cases, and more than 20 years in three others, with no clinical manifestation of disease. This study confirms that EDTA-dependent PTCP is a phenomenon related to the presence of natural autoantibodies with antiplatelet activity, devoid of pathological significance. Its clinical interest resides in the need for its prompt and certain recognition in order to avoid unnecessary examinations and therapeutic interventions. The best and most rapid technique for obtaining accurate platelet counts in PTCP subjects is to collect and examine EDTA blood at 37 degrees C; however, clumping will still be present in about 20% of these cases, and even in citrated blood. To obviate this phenomenon, blood should be collected in ammonium oxalate, and platelets counted in a Burker chamber.

Once-weekly epoetin beta is highly effective in treating anaemic patients with lymphoproliferative malignancy and defective endogenous erythropoietin production

Epoetin beta, three-times weekly (t.i.w.), is effective in reversing anaemia in lymphoproliferative disorders. The current study investigated whether an epoetin beta dose of 30,000 IU given subcutaneously once weekly (q.w.) was at least as effective as 10,000 t.i.w. administration in anaemic patients with lymphoproliferative malignancy and defective endogenous erythropoietin (Epo) production. Overall, 241 anaemic patients with multiple myeloma, low-grade non-Hodgkin's lymphoma or chronic lymphocytic leukaemia, all with serum Epo values </= 100 mU/ml, were randomized to receive the q.w. (n = 119) or t.i.w. (n = 122) regimen for 16 weeks. The primary efficacy criterion, i.e. the time-adjusted area under the haemoglobin-time curve from weeks 5-16, was comparable between the q.w. and t.i.w. groups [difference = - 0.20 g/dl (90% confidence interval - 0.52-0.11)]. Moreover, response rates were high and similar in both arms (72%vs 75%, q.w. and t.i.w. groups respectively). Baseline serum Epo was predictive of response: the lower serum Epo, the higher the likelihood of response (P = 0.002). Thus, epoetin beta administered q.w. is an effective and convenient treatment for anaemia in patients with lymphoproliferative disorders. Tailoring this treatment modality to subjects with defective endogenous Epo production represents a rational use of epoetin from both a medical and a community perspective.

Serum soluble interleukin 2 receptor alpha in human cancer of adults and children: a review

Cancer growth and development is associated with the stimulation of the innate immune system, including enhanced interleukin 2 receptor (IL-2R) expression in immune cells and its shedding into the circulation in a soluble form of sIL-2Ralpha. In most haematological malignancies, including different types of leukaemias and lymphomas, sIL-2Ralpha has been found to be released directly from the surface of neoplastic cells thus reflecting the tumour bulk, turnover and activity. Several studies have proved that not only lymphoid cancer cells, but also some non-lymphoid cancer cells, express IL-2R on their surface. They include malignant melanoma and carcinomas of the kidney, head and neck, oesophagus and lung. It is suggested that in most malignant solid tumours, elevated levels of sIL-2Ralpha are likely to be the product of normal peripheral mononuclear cells activated in response to the neoplasm's growth or that they are released from activated lymphoid cells infiltrating neoplastic tissues. This latter hypothesis has been proved by discovering the high expression of CD25 on the cell surface of most of these cells. Although the precise source and biological role of sIL-2Ralpha has not been clarified definitively, pretreatment serum levels of sIL-2Ralpha have been shown to reflect the activity, advancement and biological aggressiveness of many types of cancer in adults and children as well as to correlate with prognosis and overall survival. The possibility of enriching the diagnostic tools of oncologists with a new biochemical marker of activity of neoplasms resulted in numerous studies and reports concerning the clinical usefulness of sIL-2Ralpha measurements in adult and, less frequently, in paediatric malignancies. This article presents the actual knowledge concerning the structure, source and biological function of sIL-2Ralpha in patients with haematological and non-haematological malignancies. The authors review the published data on clinical applicability of soluble IL-2Ralpha determination in terms of diagnostics, prognosis and treatment monitoring of particular types of malignant disorders both in adults and in children. They also provide an insight into the clinical usefulness of sLL-2Ralpha-blocking antibodies in patients with cancer, and in those who reject organ transplants, develop graft-versus-host disease after allogeneic bone marrow transplantation and are affected with autoimmune disorders.

Treatment of B-lymphoproliferative disorder with a monoclonal anti-interleukin-6 antibody in 12 patients: a multicenter phase 1-2 clinical trial

Severe T-cell immunodeficiency after solid organ or bone marrow transplantation may result in the uncontrolled outgrowth of latently Epstein-Barr virus-infected B cells, leading to B-lymphoproliferative disorder (BLPD). Given the potentially important pathogenic role of IL-6 in BLPD, it was tested whether the in vivo neutralization of IL-6 by a monoclonal anti-IL-6 antibody could contribute to the control of BLPD. Safety and efficacy were assessed in 12 recipients of transplanted organs who had BLPD refractory to the reduction of immunosuppression over 8 days. Five patients received 0.4 mg/kg per day. The next 7 patients received 0.8 mg/kg per day. Treatment was scheduled to last 15 days. It was completed in 10 patients, and in the other 2 patients was discontinued early (days 10 and 13, respectively) because of disease progression. Treatment tolerance was good, and no major side effects were observed. High C-reactive protein levels were found in 9 patients before treatment but were normalized under treatment in all patients, demonstrating efficient IL-6 neutralization. Complete remission (CR) was observed in 5 patients and partial remission (PR) in 3 patients. Relapse was observed in 1 of these 8 patients in whom remission was observed. This relapse was unresponsive to treatment. Disease was stable in 1 patient, but it progressed in 3 patients. Seven patients are alive and well. Two patients died because of disease progression, and 3 patients died while in CR (chronic rejection in 2 patients and BLPD sequelae in 1 patient). These data suggest that the anti-IL-6 antibody is safe and should be further explored in the treatment of BLPD.

Immunophenotypic profiles in families with autoimmune lymphoproliferative syndrome

Autoimmune lymphoproliferative syndrome (ALPS) type Ia is caused by inherited defects in apoptosis and is characterized by nonmalignant lymphoaccumulation, autoimmunity, and increased alpha/beta(+) double-negative T cells (alpha/beta(+)-DNT cells). This study reports immunophenotypic findings in 166 members of 31 families with ALPS type Ia, associated with genetic mutations in the TNFRSF6 gene encoding Fas. The ALPS type Ia probands (n = 31) and relatives having both a Fas mutation and clinically proven ALPS (n = 28) showed significant expansion of CD8(+) T cells, alpha/beta(+)-DNT cells, gamma/delta(+)-DNT cells, CD3(+)/ HLA-DR(+) T cells, CD8(+)/CD57(+) T cells, and CD5(+) B cells. Relatives with Fas mutations, but without all the required criteria for ALPS (n = 42), had expansions of CD8(+) T cells, alpha/beta(+)-DNT cells, and gamma/delta(+)-DNT cells. Interestingly, relatives without a Fas mutation and with no features of ALPS (n = 65) demonstrated a small but significant expansion of CD8(+) T cells, both DNT cell subsets, and CD5(+) B cells. As compared to unrelated healthy controls, lymphocyte subset alterations were greatest in the probands, followed by the relatives with mutations and ALPS. Probands and relatives with mutations and ALPS also showed a lower number of CD4(+)/CD25(+) T cells that, in combination with an independent increase in HLA-DR(+) T cells, provided a profile predictive of the presence of clinical ALPS. Because quantitative defects in apoptosis were similar in mutation-positive relatives regardless of the presence of clinical ALPS, factors, other than modifiers of the Fas apoptosis pathway, leading to these distinctive immunophenotypic profiles most likely contribute to disease penetrance in ALPS.

Characterization of Crohn disease in X-linked inhibitor of apoptosis-deficient male patients and female symptomatic carriers

BACKGROUND

Crohn disease is an inflammatory bowel disease (IBD) with a complex mode of inheritance. Although nucleotide binding and oligomerization domain containing 2 (NOD2) is the strongest risk factor, the cause of Crohn disease remains unknown in the majority of the cases. X-linked inhibitor of apoptosis (XIAP) deficiency causes X-linked lymphoproliferative syndrome type 2. IBD has been reported in some XIAP-deficient patients.

OBJECTIVE

We characterize the IBD affecting a large cohort of patients with mutations in XIAP and examine the possible pathophysiologic mechanisms.

METHODS

We performed a phenotypical and histologic analysis of the IBD affecting 17 patients with hemizygous mutations in XIAP, including 3 patients identified by screening 83 patients with pediatric-onset IBD. The X chromosome inactivation was analyzed in female carriers of heterozygous XIAP mutations, including 2 adults with IBD. The functional consequences of XIAP deficiency were analyzed.

RESULTS

Clinical presentation and histology of IBD in patients with XIAP deficiency overlapped with those of patients with Crohn disease. The age at onset was variable (from 3 months to 41 years), and IBD was severe and difficult to treat. In 2 patients hematopoietic stem cell transplantation fully restored intestinal homeostasis. Monocytes of patients had impaired NOD2-mediated IL-8 and monocyte chemoattractant protein 1 (MCP-1) production, as well as IL-10, in response to NOD2 and Toll-like receptor 2/4 costimulation. Nucleotide binding and oligomerization domain containing 1 (NOD1)-mediated IL-6 and IL-8 production was defective in fibroblasts from XIAP-deficient patients. The 2 heterozygous female carriers of XIAP mutations with IBD displayed abnormal expression of the XIAP mutated allele, resulting in impaired activation of the NOD2 pathway.

CONCLUSION

IBD in patients with XIAP deficiency is similar to Crohn disease and is associated with defective NOD2 function in monocytes. Importantly, we report that it is not restricted to male patients because we identified 2 symptomatic female heterozygous carriers of XIAP mutations.

Serum soluble interleukin-6 receptor in MRL/lpr mice is elevated with age and mediates the interleukin-6 signal

The characteristics of soluble interleukin-6 receptor (sIL-6R) in murine sera were examined. To investigate a relationship between serum sIL-6R level and autoimmune diseases, quantitative analysis of serum sIL-6R in MRL/lpr mice was performed by an enzyme-linked immunosorbent assay. The serum sIL-6R level in MRL/lpr mice of both sexes was below the detection limit (< 1.0 ng/ml) at 8 weeks of age, but it increased in accordance with age and reached 42 +/- 9.3 ng/ml in female and 31 +/- 13 ng/ml in male mice at 30 weeks of age. In MRL/+ mice, although an age-associated increase in serum sIL-6R level was observed, it was much less extensive than that in MRL/lpr mice. Elevated serum sIL-6R level at the age of 30 weeks was observed in female and male (NZB x NZW)F1 mice (32 +/- 10 ng/ml and 17 +/- 5.0 ng/ml, respectively), and male BXSB/Mpj Yaa mice (42 +/- 18 ng/ml), suggesting that elevated serum sIL-6R in aged mice is one of the characteristics of autoimmune-prone mice. Quantitative analysis of serum IL-6 in MRL/lpr revealed that the serum sIL-6R level correlated well with the serum IL-6 level. We also showed that sIL-6R in the sera from MRL/lpr mice could mediate the IL-6 functions through the IL-6 signal-transducing receptor component gp130, suggesting that elevated production of sIL-6R may partly contribute to development of autoimmune disease in MRL/lpr mice.

Increases in circulating and lymphoid tissue interleukin-10 in autoimmune lymphoproliferative syndrome are associated with disease expression

Autoimmune lymphoproliferative syndrome (ALPS) is an inherited disorder in which genetic defects in proteins that mediate lymphocyte apoptosis, most often Fas, are associated with enlargement of lymph nodes and the spleen and a variety of autoimmune manifestations. Some patients with ALPS have relatives with these same apoptotic defects, however, who are clinically well. This study showed that the circulating levels of interleukin 10 (IL-10) were significantly higher (P <.001) in 21 patients with ALPS than in healthy controls. Moreover, the peripheral blood mononuclear cells (PBMCs) and lymphoid tissues of these patients with ALPS contained significantly higher levels of IL-10 messenger RNA (mRNA; P <.001 and P <.01, respectively). By fractionating PBMC populations, disproportionately high concentrations of IL-10 mRNA were found in the CD4(-)CD8(-) T-cell population, expansion of which is virtually pathognomonic for ALPS. Immunohistochemical staining showed intense IL-10 protein signals in lymph node regions known to contain CD4(-)CD8(-) T cells. Nonetheless, in vitro studies showed no influence of IL-10 on the survival of CD4(-)CD8(-) T cells. Overexpression of IL-10 in patients with inherited apoptotic defects is strongly associated with the overt manifestations of ALPS.

T-cell receptor gene rearrangement analysis: cutaneous T cell lymphoma, peripheral T cell lymphoma, and premalignant and benign cutaneous lymphoproliferative disorders

T-cell receptor gene rearrangement analysis is a useful technique to detect clonality and determine lineage of lymphoid neoplasms. We examined 103 patients with mycosis fungoides, Sézary syndrome, peripheral T cell lymphoma, potentially malignant lymphoproliferative disorders including pre-Sézary syndrome, large plaque parapsoriasis, lymphomatoid papulosis and follicular mucinosis, and various benign inflammatory infiltrates. A clonal rearrangement was detected in skin samples in 20 of 24 patients with mycosis fungoides and in peripheral blood samples in 19 of 21 patients with Sézary syndrome. A clonal population was also detected in seven of eight cases classified as peripheral T cell lymphoma. The potentially malignant dermatoses tended to have clonal rearrangement, with the exception of large plaque parapsoriasis, and further follow-up is needed to correlate clonality with the disease course. These studies demonstrate the value of molecular genetics as an adjunct to morphology in the examination of patients with cutaneous lymphoproliferative disease.

Cold agglutinin disease

Primary chronic cold agglutinin disease (CAD) is a well-defined clinicopathologic entity in which a specific, clonal lymphoproliferative B-cell bone marrow disorder results in autoimmune hemolytic anemia. The immune hemolysis is entirely complement-dependent, predominantly mediated by activation of the classical pathway and phagocytosis of erythrocytes opsonized with complement protein C3b. Typical clinical features in CAD have diagnostic and therapeutic implications. Pharmacologic treatment should be offered to patients with symptom-producing anemia or disabling circulatory symptoms. CAD should not be treated with corticosteroids. Based on an individualized approach, rituximab monotherapy or rituximab-fludarabine in combination is recommended as first-line therapy. Rituximab-bendamustine is still an investigational therapy. Although complement-modulating agents are still to be considered experimental in CAD, therapy with the anti-C1s monoclonal antibody TNT009 seems promising.

Epstein-Barr virus-related disorders in children undergoing renal transplantation with tacrolimus-based immunosuppression

In children undergoing renal transplantation, Epstein-Barr virus- (EBV) related disorders, including posttransplant lymphoproliferative disorder, constitute a major complication associated with tacrolimus-based immunosuppression. In this study, we reviewed the EBV complications in 81 children, all of whom had EBV serological studies before renal transplantation. We also highlight the data in a subgroup of 30 children transplanted more recently who were monitored sequentially for EBV symptoms and signs and with immunological studies, and in whom the donor EBV serology was also determined. During a mean follow-up time of 3.9+/-2.3 years, 19 children developed symptomatic Epstein-Barr virus (EBV*) infection. This consisted of the clinical syndrome of infectious mononucleosis in 7 children; in addition, 10 children developed posttransplant lymphoproliferative disorder (PTLD), which was histologically confirmed in 8, and 2 others developed malignant lymphoma. Recipient seronegativity (EBV-) and donor EBV seropositivity (EBV+) predicted a high probability for seroconversion (P=0.0072) and for developing PTLD or malignancy (P<0.01). In the subgroup of 30 children studied prospectively, seroconversion occurred in 15 of 19 seronegative recipients of EBV seropositive grafts at 6.6+/-2.6 months (mean+/-SD) after transplantation. Seven children developed symptomatic EBV infection (including three with PTLD) in association with seroconversion and a rise in EBV viral load in the peripheral blood, demonstrated by an EBV-specific polymerase chain reaction (EBV-PCR). Of 15 seroconverters, 7 who developed symptomatic infection had received EBV+ grafts; 8 others with EBV+ grafts seroconverted but did not become symptomatic. These two subgroups did not differ in age, rejection rate, antiviral prophylaxis, or level of immunosuppression. In the overall group of 81 children, only the two with malignant lymphoma who were managed with chemotherapy had substantial morbidity. The 10 individuals with PTLD received a regimen combining i.v. ganciclovir and CytoGam, and stopping or reducing the tacrolimus. Four children with associated marked tonsilar growth underwent tonsillectomy. All 19 individuals with EBV disorders resolved their symptoms and signs, and all have maintained good allograft function during a follow-up time of 3.0+/-2.5 years (mean+/-SD) after the development of symptomatic EBV infection, PTLD, or malignancy. We conclude that seronegative recipients of EBV+ grafts are at high risk for developing EBV-related disorders after renal transplantation under tacrolimus-based immunosuppression, although the ultimate clinical outcomes have been remarkably good. These data form the basis for formulating strategies for early identification of children at risk for EBV complications, and for instituting preventive and treatment strategies that permit these children to realize the substantial benefits offered by tacrolimus-based immunosuppression.

Pilot trial on the use of etanercept and methylprednisolone as primary treatment for acute graft-versus-host disease

Clinical and preclinical data indicate that tumor necrosis factor (TNF)-alpha is an important mediator of acute graft-versus-host disease (aGVHD) after allogeneic bone marrow transplantation. We completed a study using etanercept, a fusion protein capable of neutralizing TNF-alpha, for the initial treatment of aGVHD. Etanercept (25 mg subcutaneously) was administered twice weekly for 16 doses, along with methylprednisolone (2 mg/kg) and tacrolimus for biopsy-proven aGVHD. Twenty patients with a median age of 47 years (range, 8-63 years) were enrolled. Fourteen patients with grade II aGVHD (11 family donors and 3 unrelated donors) and 6 patients with grade III aGVHD (3 family donors and 3 unrelated donors) were treated. Twelve patients completed 16 doses of therapy, and 8 received 5 to 15 doses. Reasons for not completing all doses of etanercept included progression of aGVHD (n = 4), relapsed leukemia (n = 2), progression of pulmonary and central nervous system lesions (n = 1), and perforated duodenal ulcer (n = 1). Fifteen (75%) of 20 patients had complete resolution of aGVHD within 4 weeks of therapy. Increasing levels of soluble TNF receptor 1 plasma concentration during the first 4 weeks of therapy indicated progression of aGVHD in 5 patients. In contrast, for 15 responding patients, soluble TNF receptor 1 plasma concentration levels returned to baseline. These data demonstrate the feasibility of using cytokine blockade in the early treatment of aGVHD.

Epstein-Barr Virus (EBV) DNA in Plasma Is Not Encapsidated in Patients With EBV-Related Malignancies

Epstein-Barr Virus (EBV), a ubiquitous gamma herpes virus, infects more than 95% of the human population before adulthood. Life-long persistence, usually without adverse health consequences, relies on a balance between viral latency, viral replication, and host immune response. Patients with EBV-related disease often have high levels of EBV DNA in their plasma. This study addresses whether this circulating, cell-free EBV DNA is encapsidated in virions or exists as naked genomes. First, an assay was developed, combining DNase I and quantitative real-time PCR, to discriminate encapsidated from naked EBV DNA. EBV DNA was almost always naked in the plasma of AIDS-related lymphoma patients (n = 11) and immunosuppressed/posttransplantation patients (n = 8). In contrast, infectious mononucleosis patients (n = 30) often had a mixture of encapsidated and naked EBV DNA. These findings may be important in understanding how viral load relates to disease status and in predicting response to nucleoside analogs and other antiviral therapies.

Circulating monoclonal B lymphocytes in non-Hodgkin's lymphoma

Using a sensitive flow cytometric method ("kappa-lambda analysis"), we have found monoclonal B lymphocytes in the blood of 71 of 91 patients with non-Hodgkin's lymphoma. The presence of the B lymphocytes was independent of the histologic subclassification of the patient's disease. When we performed simultaneous analysis of the surface light-chain type in tumor tissue obtained by biopsy, the apparent light-chain type of the blood monoclonal cells corresponded with that of the tumor in 21 of 23 patients (P = 0.03). There was no correlation of the presence of these cells in the blood with morphologic evidence of bone-marrow involvement by lymphoma, but there was a strong correlation with clinical staging. Studies performed during prolonged clinical remission showed that whereas 16 of 25 patients with nodular non-Hodgkin's lymphoma had persistence of monoclonal lymphocytes, none of the 14 patients with diffuse histiocytic lymphoma in remission had these findings (P less than 0.005). Our analysis for B-cell clonal excess demonstrates the persistence of circulating monoclonal lymphocytes during complete remission in patients with forms of lymphoma that have a high probability of relapse, but we did not find these cells in patients in remission from categories of lymphoma in which prolonged remission is associated with cure. It is possible that the circulating monoclonal lymphocytes in patients with lymphoma are malignant cells, and their disappearance or persistence after remission may have prognostic importance.

The heme biosynthetic pathway in lymphocytes of patients with malignant lymphoproliferative disorders

The metabolism of heme is impaired in lymphocytes of patients with malignant lymphoproliferative disorders (MLPO). Two of the enzymes of the heme biosynthetic pathway, delta-aminolevulinic acid dehydrase (ALAD) (EC 4.2.1.24) and ferrochelatase (FC) (EC 4.99.1.1) are markedly reduced. The activity of porphobilinogen deaminase (PBGD) (EC 4.3.1.8) is increased. The rate-limiting enzyme of heme biosynthesis in the liver, aminolevulinate synthase (ALAS) (EC 2.3.1.37) remains unchanged although the concentration of total heme in the lymphocytes is markedly reduced. This might reflect a lack of negative feedback inhibition by heme on ALAS activity in this system.

Preliminary experience of allogeneic stem cell transplantation for lymphoproliferative disorders using BEAM-CAMPATH conditioning: an effective regimen with low procedure-related toxicity

Autologous transplantation has an established role in the treatment of lymphoproliferative disorders, but allogeneic transplantation remains controversial. In an attempt to reduce the high procedure-related mortality reported with allografting in lymphoma, we have used BEAM (BCNU, etoposide, cytarabine and melphalan), a standard conditioning regimen for autologous transplantation. As BEAM may be insufficiently immunosuppressive to permit durable engraftment in the allogeneic setting, patients received additional pretransplant immunosuppression with the anti-CD52 antibody CAMPATH-1G from day -5 to day -1. Twelve patients (median age 46 years) underwent allogeneic transplantation for lymphoma (n = 11) or chronic lymphocytic leukaemia (n = 1) from HLA-identical (n = 9) or mismatched (n = 3) sibling donors. Cyclosporin A and methotrexate were used as graft-versus-host disease (GVHD) prophylaxis. One patient died of progressive lymphoma at day +12, the remaining 11 patients engrafted rapidly, with eight demonstrating full donor chimerism. One patient had an episode of rejection and received a further stem cell infusion with sustained recovery. Only one patient developed GVHD (grade I). The low incidence of acute GVHD may be in part related to persisting levels of in vivo CAMPATH-IG at the time of transplantation. Of 11 evaluable patients, nine achieved complete remission (CR), and a further patient achieved CR after donor lymphocyte infusion at 5 months. Our preliminary experience is that this regimen was well tolerated with a low risk of GVHD and appears no more toxic than a BEAM autograft. Further follow-up is required to see whether the low incidence of GVHD impacts upon relapse risk.

Post-transplant lymphoproliferative disease and other Epstein-Barr virus diseases in allogeneic haematopoietic stem cell transplantation after introduction of monitoring of viral load by polymerase chain reaction

The clinical value of monitoring of Epstein-Barr virus (EBV) viraemia by quantitative polymerase chain reaction during 1 y was evaluated. 39 recipients of allogeneic hematopoietic stem cell transplantation (SCT) were followed. More than 100 EBV genome equivalents (gEq)/ml in blood or plasma were found in 16/39 patients (41%) at 34 d (range 1-139) post-transplant. Seven of these 16 patients developed EBV disease; 3 post-transplant lymphoproliferative disease (PTLD), 1 myelitis, 1 encephalitis and 2 reactivations with fever. EBV diseases were only found in the high-risk group among recipients of mismatched related or unrelated donor grafts or in patients who underwent reduced-intensity conditioning. In this group, 3/20 (15%) developed PTLD. Conditioning with antithymocyte globulin was significantly associated with EBV disease (p<0.01). EBV load in plasma was more strongly associated with EBV disease than viral load in blood. A cut-off level of 1000 gEq/ml plasma distinguished EBV disease from asymptomatic viraemia, but not PTLD from other EBV diseases. Weekly monitoring of EBV load in plasma in high-risk patients in the first 3 months following SCT seems to be of value for prediction of EBV disease. Therapy for PTLD including rituximab was evaluated during 2 y and showed response in 4/6 cases.

Assessment of automated DNA extraction coupled with real-time PCR for measuring Epstein-Barr virus load in whole blood, peripheral mononuclear cells and plasma

BACKGROUND

Epstein-Barr virus (EBV) DNA load monitoring in blood has been shown to be essential for the diagnosis of EBV-associated diseases. However, the methods currently used to assess EBV DNA load are often time-consuming and require prior blood separation.

OBJECTIVES

The aim of this study was to evaluate the relative diagnostic value of EBV DNA load monitoring in whole blood, peripheral blood mononuclear cells (PBMCs) and plasma after automated DNA extraction using the MagNA Pure extractor followed by LightCycler real-time quantitative PCR (LC-PCR).

STUDY DESIGN

First, EBV DNA load was assessed retrospectively after automated or manual extraction on 104 PBMC specimens. Second, EBV DNA load was determined prospectively with the automated extraction procedure in the whole blood, PBMCs and plasma of 100 samples from patients with EBV-related diseases (group 1, n = 20), HIV-seropositive individuals (group 2, n = 66), and healthy EBV carriers (group 3, n = 14).

RESULTS

A good correlation was observed between automated and manual extraction on 104 PBMC specimens (r = 0.956; P < 0.0001). In the prospective study, 67 samples were positive in both whole blood and PBMCs, with a good correlation between EBV DNA loads in whole blood and PBMCs (r = 0.936; P < 0.0001). Only 18/100 samples were positive in plasma. Higher viral loads were regularly observed in the three blood compartments from group 1 than from groups 2 and 3.

CONCLUSION

This study demonstrated that an automated extraction of EBV DNA is easier to perform in whole blood or plasma than in PBMCs and facilitates the standardisation of EBV DNA measurement by real-time quantitative PCR. The quantitative detection of EBV DNA load in whole blood appeared more sensitive than in plasma for infectious mononucleosis in immunocompetent patients, probably because of a rapid loss of plasmatic EBV DNA. In transplant patients, EBV DNA load monitoring in whole blood and in plasma turned out to be equivalent in terms of feasibility and accuracy for the early diagnosis of post-transplant lymphoproliferative diseases (PTLDs).