Forest fires and deforestation in the central Amazon: Effects of landscape and climate on spatial and temporal dynamics

Forest fires and deforestation are the main threats to the Amazon forest. Extreme drought events exacerbate the impact of forest fire in the Amazon, and these drought events are predicted to become more frequent due to climate change. Fire escapes into the forest from agriculture and pasture areas. We assessed the potential drivers of deforestation and forest fires in the central Brazilian Amazon and show that over a period of 31 years (1985-2015) forest fires occurred only in years of extreme drought induced by El Niño (1997, 2009 and 2015). The association of forest fires with strong El Niños shows the vulnerability of forest to climate change. The areas deforested were closely associated with navigable rivers: 62% of the total deforestation from 2000 to 2018 was located within the 2 km of rivers. There was a notable increase in deforestation and forest fire during the 2015 El Niño in comparison to previous years. Only a small part of the forest that burned was deforested in the years following the wildfires: 7% (1997), 3% (2009) and 1.5% (2015). Forest close to roads, rivers and established deforestation is susceptible to deforestation and fire since these areas are attractive for agriculture and pasture. Indigenous land was shown to be important in protecting the forest, while rural settlement projects attracted both forest fire and deforestation. Of the total area in settlement projects, 40% was affected by forest fires and 17% was deforested. Rivers are particularly important for deforestation in this part of Amazonia, and efforts to protect forest along the rivers are therefore necessary. The ability to predict where deforestation and fires are most likely to occur is important for designing policies for preventative actions.

Wildfires as a major challenge for natural regeneration in Atlantic Forest

The natural regeneration management is a good strategy of ecological restoration of the Atlantic Forest, one of the most devastated biomes on the planet. However, the frequent occurrence of wildfires is one of the challenges to the success of this method. The objective of this study was to evaluate the effects of wildfires on forest dynamics in Atlantic Forest. The studied area was explored during the coffee cycle when plantations replaced primary forests. We used remote sensing data to analyze the forest dynamics over a period of 50 years (1966-2016). We used the INPE burn database to find the occurrence of hot spots from 1998 to 2016. During this period, we selected the years most affected by the fires for the identification of fire scars using the Normalized Burn Ratio spectral index. From this set of information, we used the methodology of weights of evidence to relate forest dynamics and wildfire events with biophysical and anthropic variables. The results showed that in 1966 the forest area accounted for 8.01% of the land cover, and in 2016 this number rose to 18.55% due to the spontaneous natural regeneration process. The regenerating areas were mainly related to the proximity of the remaining fragments and the portions of the landscape receiving the least amount of global solar radiation. The proximity to urban areas, roads and highways, damaged regeneration and favored both deforestation and wildfire events. Fire scars preferentially occur where there is greater sun exposure. It is possible to observe a negative correlation between the natural regeneration process and the fire scars. We concluded that fire severity is one of the factors that shape the landscape of the region while slowing the regeneration process in preferential areas.

Prolonged in vitro hemolysis of EDTA-anticoagulated blood after a delayed hemolytic transfusion reaction

BACKGROUND

A novel case where in vitro hemolysis was observed in plasma, but not in serum samples, obtained after the onset of a severe delayed hemolytic transfusion reaction is presented.

CASE REPORT

A 54-year-old woman received 2 units of blood during an orthopedic procedure. She had received transfusion 30 years earlier, and testing before transfusion revealed no alloantibodies. The patient returned 12 days after the transfusion with a Hb level of 54 g per L due to a severe delayed hemolytic reaction caused by anti-K. The plasma and serum samples were grossly hemolysed on Day 12. On Day 14, the serum samples showed no evidence of hemolysis; however, the EDTA sample remained grossly hemolysed. This discrepancy was not identified until Day 19. Due to concerns of ongoing apparent severe hemolysis, the patient was unnecessarily treated with IVIG and corticosteroids. The in vitro hemolysis was still present at 75 days, despite complete normalization of her Hb, bilirubin, and LDH levels. The phenomenon had resolved by 125 days.

CONCLUSION

This in vitro artifact has not been previously reported and the mechanism remains unclear. Both plasma and serum samples should be observed for hemolysis when evaluating a patient with a severe delayed hemolytic transfusion reaction.

Reporting of near-miss events for transfusion medicine: improving transfusion safety

BACKGROUND

Half of the reported serious adverse events from transfusion are a consequence of medical error. A no-fault medical-event reporting system for transfusion medicine (MERS-TM) was developed to capture and analyze both near-miss and actual transfusion-related errors.

STUDY DESIGN AND METHODS

A prospective audit of transfusion-related errors was performed to determine the ability of MERS-TM to identify the frequency and patterns of errors.

RESULTS

Events and near-miss events (total, 819) were recorded for a period of 19 months (median, 51/month). No serious adverse patient outcome occurred, despite these events, with the transfusion of 17,465 units of RBCs. Sixty-one events (7.4%) were potentially life-threatening or could have led to permanent injury (severity Level 1). Of most concern were 3 samples collected from the wrong patient, 13 mislabeled samples, and 22 requests for blood for the wrong patient. Near-miss events were five times more frequent than actual transfusion errors, and 68 percent of errors were detected before blood was issued. Sixty-one percent of events originated from patient areas, 35 percent from the blood bank, and 4 percent from the blood supplier or other hospitals. Repeat collection was required for 1 of every 94 samples, and 1 in 346 requests for blood components was incorrect. Education of nurses and alterations to blood bank forms were not by themselves effective in reducing severe errors. An artifactual 50-percent reduction in the number of errors reported was noted during a 6-month period when two chief members of the event-reporting team were on temporary leave.

CONCLUSION

The MERS-TM allowed the recognition and analysis of errors, determination of patterns of errors, and monitoring for changes in frequency after corrective action was implemented. Although no permanent injury resulted from the 819 events, innovative mechanisms must be designed to prevent these errors, instead of relying on faulty informal checks to capture errors after they occur.

Flow cytometry in the diagnosis of peritoneal carcinomatosis

OBJECTIVES

Peritoneal carcinomatosis is the second major cause of ascites. Because of its frequency and poor prognosis, it is important to establish an accurate diagnosis. The aim of this study was to analyze the use of a DNA index, detemined by flow cytometry in the differential diagnosis of ascites, and to compare it to the cytopathological examination.

METHODS

A prospective analysis was carried out on 67 patients (39 female, 28 male; mean age, 53+/-14 yr [range, 5-82]) with ascites of various etiologies. Peritoneal carcinomatosis was detected in 21 patients, whereas in 46 the ascites was of noncarcinomatosis origin.

RESULTS

The sensitivity of the cytopathological examination for the diagnosis of peritoneal carcinomatosis was 42.9%, and the specificity was 100%. The mean DNA index determined by flow cytometry was similar for peritoneal carcinomatosis and noncarcinomatosis patients, being 1.28 versus 1.01, respectively, in the preparations without control lymphocytes and 1.28 versus 1.04, respectively, when control lymphocytes were added. The sensitivity of DNA index cytometry was 57.1% and specificity, 93.5%. The combined use of the DNA index and cytopathological examination did not show an advantage over the use of any of the tests individually, although the DNA index was able to detect half of the cases of peritoneal carcinomatosis in which cytopathological examination was negative. Although the sensitivity was higher when the parameters were associated, the DNA index did not offer a statistically significant advantage over the use of cytopathological examination alone, which in turn had higher specificity.

CONCLUSION

The DNA index presented lower sensitivity for the diagnosis of peritoneal carcinomatosis when used alone, showing no advantage over conventional cytopathological examination. However, the DNA index was able to detect 50.0% of peritoneal carcinomatosis cases whose conventional cytopathological examinations were negative, and could be valuable in these situations.

Induction of tolerance to immunogenic tumor antigens associated with lymphomagenesis in HOX11 transgenic mice

Transgenic mice expressing human HOX11 in B lymphocytes die prematurely from lymphomas that initiate in the spleen and frequently disseminate to distant sites. Preneoplastic hematopoiesis in these mice is unperturbed. We now report that expression of the HOX11 transgene does not affect the ability of dendritic cells (DCs) to process and present foreign peptides and activate antigen-specific T cell responses. We also show that nontransgenic DCs presenting peptides derived from the human HOX11 protein are highly efficient stimulators of autologous T cells, whereas transgenic T cells are nonresponsive to peptides derived from the HOX11 transgene and the murine Meis1 protein. HOX11 transgenic mice thus show normal development of tolerance to immunogenic antigens expressed throughout B cell maturation. DCs pulsed with cell lysates prepared from lymphomas, obtained from HOX11 transgenic mice with terminal lymphoma, activate T cells from nontransgenic and premalignant transgenic mice, whereas T cells isolated from lymphomatous transgenic mice are nonresponsive to autologous tumor cell antigens. These data indicate that HOX11 lymphoma cells express tumor-rejection antigens that are recognized as foreign in healthy transgenic mice and that lymphomagenesis is associated with the induction of anergy to tumor antigen-specific T cells. These findings are highly relevant for the development of immunotherapeutic protocols for the treatment of lymphoma.

Screening for azathioprine toxicity: a pharmacoeconomic analysis based on a target case

The risk of azathioprine-induced myelosuppression can be predicted by detecting patients with intermediate or low thiopurine methyltransferase (TPMT) activity. Population studies have shown that 89% of whites have high TPMT activity, 11% have intermediate TPMT activity, and 0.3% have low TPMT activity. Three specific mutations in the TPMT gene that cause decreased TPMT activity have recently been identified. Patients homozygous for the TPMT mutations have low TPMT activity, and patients heterozygous for TPMT mutations have intermediate TPMT activity. This has led to the development of a technique for TPMT genotype analysis that will identify patients at risk of azathioprine-induced myelosuppression. We report a case of a patient with bullous pemphigoid who experienced azathioprine-induced myelosuppression and who was later found to be homozygous for TPMT mutant alleles. Using the cost of treatment required for this patient and the estimated population prevalence of TPMT mutations, we examined the cost impact of screening for TPMT mutations in all patients being considered for azathioprine therapy. We calculated that screening is cost-neutral assuming patients homozygous for TPMT mutations experience myelosuppression, and that it is cost-beneficial assuming patients heterozygous for TPMT mutations also experience myelosuppression while receiving azathioprine. Screening patients for TPMT mutations will reduce the risk of azathioprine-induced myelosuppression, and our study suggests that it may also be a cost-attractive strategy.

A gel technology system to determine postpartum RhIG dosage

Failures of Rh immune globulin (RhIG) prophylaxis occur when the dose is too small. We report a test using a gel technology (GT) method to replace the Kleihauer-Betke (K-B) test to assess fetomaternal hemorrhage (FMH) and assist in determining the minimum necessary dose of RhIG. Cord blood (O, D+) was mixed with adult blood (O D-) to mimic an FMH of 10 mL, 20 mL, 28 mL, and 40 mL. Test samples were incubated with anti-D at known concentrations and centrifuged. The supernatant was titrated against D+ and D- red cells using GT and an interpretation of the required RhIG dose was made. Results were compared with the K-B test. Results were easily discernible and interpretations leading to determination of recommended RhIG dosage were reproducible. Correlation to standard K-B testing was confirmed. Elapsed time for result availability by GT testing was 60 minutes, with a direct technical time requirement of 30 minutes. The GT system is easier, objective, and quantitative, and compares well to the standard K-B test. A single procedure will allow assessment of the extent of FMH in the great majority of cases. This technique works well in determining the appropriate dose of anti-D required to treat D- patients with D+ newborns. There are potential cost savings in decreased use of RhIG, less direct technical time required, and more rapid availability of results.

A model for spontaneous B-lineage lymphomas in IgHmu-HOX11 transgenic mice

HOX11, a divergent homeodomain-containing transcription factor, was isolated from the breakpoint of the nonrandom t(10;14)(q24;q11) chromosome translocation found in human T cell acute lymphoblastic leukemias. The translocation places the HOX11 coding sequence under the transcriptional control of TCR alpha/delta regulatory elements, resulting in ectopic expression of a normal HOX11 protein in thymocytes. To investigate the oncogenic potential of HOX11, we targeted its expression in lymphocytes of transgenic mice by placing the human cellular DNA under the transcriptional control of Ig heavy chain or LCK regulatory sequences. Only IgHmu-HOX11 mice expressing low levels of HOX11 were viable. During their second year of life, all HOX11 transgenic mice became terminally ill with more than 75% developing large cell lymphomas in the spleen, which frequently disseminated to thymus, lymph nodes, and other nonhematopoietic tissues. Lymphoma cells were predominantly clonal IgM+IgD+ mature B cells. Repopulation of severe combined immunodeficient mice with cells from hyperplastic spleens indicated that the HOX11 tumor phenotype was transplantable. Before tumor development, expression of the transgene did not result in perturbations in lymphopoiesis; however, lymphoid hyperplasia involving the splenic marginal zones was present in 20% of spleens. Our studies provide direct evidence that expression of HOX11 in lymphocytes leads to malignant transformation. These mice are a useful model system to study mechanisms involved in transformation from B-lineage hyperplasia to malignant lymphoma and for testing novel approaches to therapy. They represent a novel animal model for non-Hodgkin's lymphoma of peripheral mature B cell origin.

Verrucous cyst

A verrucous cyst is an unusual, histopathologically distinctive, epidermoid cyst characterised by verrucous changes in its wall. We report two cases of verrucous cysts in different patients, one on the back and the other on the cheek. Clinically, the lesions were thought to represent an epidermoid cyst and a basal cell carcinoma, respectively. Histologically, we found in both cases an intradermal epidermoid cyst lined by a stratified squamous epithelium with focal cytopathogenic viral changes, consisting of papillomatosis, ortho- and parakeratosis, and hypergranulosis. One case also showed, within the squamous areas of the hyperplastic epithelium, occasional squamous eddies. These histopathological features support the diagnosis of verrucous cyst, which may represent a manifestation of human papillomavirus infection. This virus may induce cyst formation or just infect a pre-existing one.

[Dermatitis artefacta]

We report a case of a 29-year-old man presenting skin ulcerations on both sides of the mandible. The diagnosis of dermatitis artefacta was based on the morphology and evolution of the lesions, on the patient's borderline personality, on the objects found in his possession, and a later admission of having an involvement in the aggravation of the lesions.

Acute gouty synovitis associated with "urate milk"

OBJECTIVE

To analyze the clinical features of acute gouty synovitis associated with thick, milky white, "chalky," urate laden synovial effusions, and to investigate the effects on synovial white blood cell (WBC) counts when leukocyte-rich rheumatoid effusions are incubated with a urate packed milky synovial fluid.

METHODS

Five patients (all men, mean age 70.8 years) with acute gouty synovitis (acute arthritis in 3, acute bursitis in 2) associated with "urate milk" were studied between 1993 and 1996.

RESULTS

Synovial effusions were thick, "chalky," and appeared "milky" white. The fluids were packed with monosodium urate (MSU) crystals, which sedimented upon standing, leaving a clear supernatant containing a few MSU crystals. The presence of massive amounts of MSU crystals and crystal clumps interfered with accurate determination of synovial WBC counts. Four fluids showed "a few leukocytes," and one a WBC count of 6750/mm3 with 91% neutrophils and several intraleukocytic crystals. Four patients had subcutaneous tophi. Of the risk factors associated with development of gout, the most frequent was ethanol abuse, in 4 and possibly all 5 patients. Incubation of leukocyte-rich rheumatoid synovial effusions with urate laden knee fluid from Patient 5 produced a greater reduction in synovial WBC counts compared to controls.

CONCLUSION

Milky white synovial effusions containing massive quantities of urate crystals (referred to as "urate milk") may rarely occur in the setting of acute gouty arthritis or bursitis. Ethanol abuse appears to be a risk factor associated with the development of hyperuricemia and gout in these patients.

Changes in activated protein C resistance during normal pregnancy

OBJECTIVE

The objective of this study was to determine the changes in activated protein C resistance that occur during normal pregnancy.

STUDY DESIGN

In this cross-sectional study activated protein C was measured in 128 women with normal pregnancies in the first, second, and third trimesters and in nonpregnant control subjects with 24 to 39 women in each group. In addition, factor V, factor VIII, free protein S, and functional protein C were measured and correlated with activated protein C levels. Polymerase chain reaction for factor V Leiden mutation was performed.

RESULTS

There was a significant fall in the activity of activated protein C in the second and third trimesters of pregnancy (p < 0.05). This was related to increased factor VIII and decreased free protein S levels (p = 0.002, R2 = 0.20). The prevalence of the factor V Leiden mutation was 7.3%.

CONCLUSION

Resistance to activated protein C is increased in the second and third trimesters of pregnancy. This is related to the alterations in other coagulation proteins, a phenomenon normally occurring during pregnancy.

Loss of functional cell surface transforming growth factor beta (TGF-beta) type 1 receptor correlates with insensitivity to TGF-beta in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common form of adult leukemia in Western countries, and there is significant variability in survival within CLL clinical stages. Earlier studies showed that CLL cells produce and are usually growth inhibited by transforming growth factor beta type 1 (TGF-beta1), suggesting a mechanism for the clinically indolent course of most CLL. Here we studied the mechanism by which CLL cells from about one-third of the patients are insensitive to TGF-beta1. Of the 13 patients studied, CLL cells isolated from the peripheral blood of 8 patients were sensitive to growth inhibition by TGF-beta1, as determined by incorporation of tritiated thymidine, whereas those from 5 patients were completely resistant to TGF-beta1. As judged by binding of radiolabeled TGF-beta1 followed by cross-linking and immunoprecipitation with anti-receptor antisera, CLL cells sensitive to TGF-beta1 exhibited normal cell surface expression of both types 1 and 2 TGF-beta receptors. In contrast, all CLL cells resistant to TGF-beta1 exhibited no detectable surface type I receptors able to bind TGF-beta1, but normal expression of type II receptors. Both TGF-beta1-sensitive and TGF-beta1-resistant CLL cells contained normal amounts of both type 1 and type 2 receptor mRNAs. Specific loss of type 1 receptor expression represents a new mechanism by which cells acquire resistance to TGF-beta1-mediated growth inhibition in the development and progression of human lymphoproliferative malignancies.

Transforming function of the HOX11/TCL3 homeobox gene

The HOX11/TCL3 homeobox gene was identified at the breakpoint region in pediatric T-cell acute lymphoblastic leukemia harboring 10q24 chromosomal translocations. We previously reported that primary murine bone marrow cells transduced ex vivo with a recombinant HOX11-containing retrovirus, MSCV-HOX11, gave rise to cell lines at high frequency having characteristics of early myeloid cells. Cell lines were also established from the bone marrow and spleen of transplant recipients sacrificed 5 months after engraftment with MSCV-HOX11-transduced bone marrow cells. These latter lines, which exhibited a more differentiated myelomonocytic phenotype, harbored proviruses encoding a smaller HOX11 protein. None of the mice that received HOX11-expressing bone marrow cells or myeloid cell lines developed leukemia during 6-month observation periods. Here, we report that two bone marrow transplant recipients eventually developed T-cell acute lymphoblastic leukemia-like malignancies at 7 and 12 months posttransplant, indicating that progression to a fully malignant state required additional mutations. One tumor synthesized full-length HOX11 whereas the other expressed the smaller version of the protein. The smaller HOX11 protein suffered a carboxyl-terminal truncation. We subsequently constructed MSCV-based retroviral vectors expressing deleted forms of HOX11 and identified an amino-terminal region that was dispensible for generation of myeloid cell lines having a similar phenotype as those induced by full-length HOX11. We thus conclude that regions near the amino and carboxyl termini of HOX11 are not essential for transforming function, nor do they appear to determine the lineage or stage of differentiation of the target cell for transformation.

Immunosuppressive toxicity of CAMPATH1H monoclonal antibody in the treatment of patients with recurrent low grade lymphoma

We have studied, as part of a group of international multicenter phase II clinical trials, the toxicity and effectiveness of CAMPATH1H administered intravenously three times a week in an outpatient setting to patients with recurrent or progressive low grade lymphoma. We report here on the toxicity and therapeutic results of the first seven patients treated before the study was closed prematurely because of unacceptable toxicity. Classical complete or partial responses of treatment were seen in three of seven patients. One complete response lasted 8.5 months and the other complete response is ongoing at 1 year. Responses occurred in nodal sites as well as in skin and peripheral blood. The first three or four antibody infusions in each patient was associated with grade 1 or 2 side-effects including rigor, fever, facial flushing, nausea, vomiting, hives, wheezes, hypotension, and/or diarrhea but these subsequently decreased or disappeared. The most significant toxicity was profound lymphopenia and associated infection, usually viral. Six of seven patients had culture or serologically documented infections and four patients had two or more such episodes. All infections responded to temporary discontinuation of antibody therapy and appropriate antiviral or antibiotic agents. We conclude that CAMPATH1H monoclonal antibody has therapeutic activity against low grade non-Hodgkin's lymphoma but that this activity is limited by marked lymphopenia and an unacceptably high frequency of serious infection at the dose and schedule used in this trial.

SBH-1, a novel Reed-Sternberg-like cell line capable of inducing tumors in SCID mice: immunophenotypic, cytogenetic, and cytokine expression profiles

A new cell line, SBH-1, with the morphologic, immunophenotypic, and karyotypic features consistent with those of Reed-Sternberg (RS) and Hodgkin (H) cells, has been established from the pleural effusion of a patient. The cytologic appearance of SBH-1 cells is characteristic of multinucleate RS and mononuclear H cells, all containing inclusion-like nucleoli. The SBH-1 cells express CD30, CD15, CD25, CD71, CD45, CD20, CD22, and bcl-2 protein and are negative for epithelial membrane antigen. Cytogenetic analysis showed multiple clonal abnormalities with breakpoints at 14q32, 6q21, and 11q23. The Ig heavy chain genes and both Ig light chain genes were rearranged in SBH-1 cells, whereas the bcl-2 gene was in germline configuration. Messages for the cytokines interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha, and transforming growth factor-beta and the cytokine receptors IL-2R, IL-4R, IL-6R, and IL-7R were detected by reverse transcription-polymerase chain reaction analysis. Xenotransplantation of SBH-1 cells into severe combined immunodeficient (SCID) mice led to local and disseminated tumor growth. The cytologic, histologic, and immunohistochemical features of SBH-1 cells in SCID mouse tumors were typical of RS and H cells. The SBH-1 cell line will be useful in the study of RS and H cell biology, inasmuch as it represents a cell line obtained from a previously untreated patient.

Sequence preservation of the third exon of the bcl-2 gene in non-Hodgkin's lymphoma: absence of somatic hypermutation

The t(14;18) translocation juxtaposes the bcl-2 gene on chromosome 18 to a joining (J) gene segment of the immunoglobulin heavy chain gene (IgH) on chromosome 14. Up to 85% of non-Hodgkin's lymphomas (NHL) are t(14;18) positive. Recent reports have documented point mutations in the second exon of translocated bcl-2 alleles and postulated that immunoglobulin variable (V) region somatic hypermutation, related to Ig sequences approximately 250 Kb downstream, may be mediating these mutations. We have examined the third exon of bcl-2, directly adjacent to Ig sequences in the t(14;18), for point mutations. In particular, we studied the translated region of exon 3 in 45 NHLs by SSCP analysis and failed to detect a single point mutation. Further, we sequenced eleven t(14;18) breakpoints, including both bcl-2 and JH sequences, and detected only one point mutation, in a JH-derived sequence. We conclude that immunoglobulin V region somatic hypermutation does not induce point mutations into the t(14;18) breakpoint region or into the translated region of the third exon of bcl-2 alleles involved in the t(14;18) translocation, conserving the membrane insertion properties of the carboxyl tail of this protein.

Alterations of the p53 tumor suppressor gene in diffuse large cell lymphomas with translocations of the c-MYC and BCL-2 proto-oncogenes

Diffuse large cell lymphomas are aggressive tumors of B-cell origin. In some cases they arise from low-grade follicular lymphomas carrying the t(14;18) translocation, an event that leads to the overexpression of the BCL-2 gene product. More frequently, however, they lack the t(14;18) translocation. Rearrangements of the c-MYC proto-oncogene and mutations of the p53 tumor suppressor gene have also been documented in these lymphomas. This study examines the extent to which alterations in the BCL-2, c-MYC, and p53 genes co-exist within individual lymphomas. Eight diffuse large cell lymphoma cell lines and 11 diffuse large cell lymphoma tumors were assessed for genetic alterations in these three genes. Our results indicate that there is a heterogeneity in the oncogene/suppressor gene profile among diffuse large cell lymphomas. Two cell lines and one tumor carried alterations in all three genes, one cell line carried alterations of c-MYC and p53, and one primary tumor and one cell line carried p53 mutations and the t(14;18). Single alterations of BCL-2 and p53 were also observed. Another cell line had no alterations in any of these genes. The heterogeneity indicates that varied mechanisms may be involved in the generation of diffuse large cell lymphomas.

Detection of occult lymphoma in the peripheral blood and bone marrow of patients with untreated early-stage and advanced-stage follicular lymphoma

PURPOSE

The object of this study was to compare the relative sensitivities of morphologic, immunophenotypic, gene rearrangement, cytogenetic, and polymerase chain reaction (PCR) analyses in the detection of lymphoma cells in the bone marrow and peripheral blood of patients with follicular lymphoma.

PATIENTS AND METHODS

Bone marrow and peripheral-blood samples from 28 newly diagnosed patients with follicular lymphoma referred from several different medical centers were assessed. Routine morphologic assessment was performed initially and the remainder of the sample was aliquoted for DNA extraction to be used for gene rearrangement and PCR analyses and for immunophenotypic and cytogenetic analyses where a sufficient amount of sample remained.

RESULTS

Morphologic assessment of the bone marrow was positive for lymphoma cells in 11 of 28 patients. PCR amplification of t(14;18) breakpoint DNA detected lymphoma cells in 17 of 24 patients assessed. Morphologic assessment detected lymphoma cells in three bone marrow samples that were negative by PCR. PCR analysis was the only method able to detect circulating lymphoma cells in peripheral blood at diagnosis and was positive in 15 of 24 samples. The other methods of assessment did not show lymphoma in any samples in which lymphoma was not detected by morphologic or PCR analysis. Lymphoma cells were found in the bone marrow and/or peripheral blood as frequently in early-stage patients as in advanced-stage patients.

CONCLUSION

PCR amplification of t(14;18) breakpoint DNA together with morphologic assessment had the highest yield of detecting lymphoma cells in the bone marrow and/or peripheral blood of our population of newly diagnosed patients with follicular lymphoma. The clinical significance and prognostic importance of lymphoma cells detected by PCR in the bone marrow and/or peripheral blood of newly diagnosed follicular lymphoma patients awaits long-term follow-up data of these and additional patients.

Positive antiglobulin test in association with sulindac: involvement of the Rh factor

We investigated the development of a positive direct antiglobulin test associated with the use of the nonsteroid anti-inflammatory drug sulindac. The drug was shown to be the cause of the positive direct antiglobulin test using red cells treated in vitro with solutions of native sulindac and its two major metabolites. Serum from the patient contained sulindac-dependent red cell antibodies which could not be demonstrated when red cells having the Rh phenotype D-- were employed in the test procedure. An eluate prepared from the patients' red cells reacted against untreated red cells having common Rh phenotypes, but not against target red cells with the Rh phenotypes D-- or Rh null. The eluate showed stronger reactivity against the cells having common Rh phenotypes when they were treated with solutions of a metabolite of sulindac, but failed to react against treated red cells having the Rh phenotype D-- or Rh null. The results of our investigations point to an interaction between sulindac and/or its metabolites and Rh structures on the red cell membrane as the initial step in the production of drug dependent and autoantibodies leading to the positive direct antiglobulin test.

Sensitive and reproducible detection of occult disease in patients with follicular lymphoma by PCR amplification of t(14;18) both pre- and post-treatment

The t(14;18) chromosomal translocation occurs in most follicular non-Hodgkin's lymphomas and places the Bcl-2 gene on chromosome 18q21 into the immunoglobulin JH region on chromosome 14q32. This translocation can be exploited to detect clonal malignant cells bearing this genetic alteration. A polymerase chain reaction (PCR) assay amplifying over the major breakpoint region (mbr) and minor cluster region (mcr) was developed and optimized. In this report, the sensitivity and reproducibility of this semiquantitative assay, performed on a relatively large number of clinical samples is shown. A titration curve of DNA made from a t(14;18)- cell line admixed with increasing ratios of a t(14;18)+ cell line was used to demonstrate that one t(14;18)+ cell in 100,000 t(14;18)- cells could reproducibly be detected. Occult lymphoma cells, not detected by standard morphologic analysis, were demonstrated in almost two-thirds of the bone marrow and peripheral blood specimens obtained from untreated patients with follicular lymphoma. Of 11 bone marrow samples assessed, seven were positive for occult disease by PCR amplification over the mbr and one was positive over the mcr. Of these six positive marrow samples, only three had been reported positive by standard morphologic criteria. In addition, seven of nine peripheral blood samples assessed were positive over the mbr and one additional sample was positive over the mcr. None of these were morphologically positive. Seven of the above patients would have been upstaged if these results were utilized for staging, including two of three patients with stage I or stage II disease. PCR-detectable occult disease persisted in four of four patients assessed both pre- and post-treatment, even after aggressive multi-drug combination chemotherapy in two of these patients. The clinical significance of detecting this occult disease must await the study of larger numbers of patients and the clinical outcomes of patients with occult disease and patients without occult disease.

A lineage-specific t(1;14)(q21;q32) as an early event in development of B-cell clonal expansion

We report a patient in whom a cell line of 47,XY,+X,t(1;14)(q21;q32) constitution was found in a lymph node excised from the neck. Histologic examination and immunophenotyping both in situ and by flow cytometry failed to confirm a diagnosis of B-cell lymphoma, but Southern analysis indicated the presence of B-cell clonal expansion. These observations support the concept that primary chromosomal abnormalities occur in clonal expansions in the very earliest stages of tumorigenesis.

Deletion of the long arm of chromosome 5 in essential thrombocythemia

A 51-year-old woman with no history of prior chemotherapy or radiation therapy was diagnosed with essential thrombocythemia (ET) according to the diagnostic criteria established by the Polycythemia Vera Study Group (PVSG). Cytogenetic analysis of bone marrow metaphases revealed both normal female karyotype and a single clonal abnormality, 46,XX,del(5)(q22q35). While chromosomal abnormalities have been reported in ET, their incidence is very low, and no specific abnormality has been found. Many of the reported cases of ET with chromosomal aberrations, including 5q-, do not meet the diagnostic criteria proposed by the PVSG, and may represent one of the other myeloproliferative disorders or a myelodysplastic syndrome. Furthermore, it is important to distinguish the 5q- syndrome, which may present with thrombocytosis and megakaryocytic hyperplasia, from ET. Our patient appears to be the first example of untreated ET clearly meeting the PVSG criteria in which 5q- was the only clonal abnormality seen at diagnosis.

"Jumping" translocations involving band 3q13.3 in a case of acute monocytic leukemia

We report a case of acute monocytic leukemia (FAB-5a) with a very aggressive clinical course and multiple chromosomal abnormalities. There were several sublines, each with trisomy 8 and a translocation involving 3q13.3 as a common breakpoint region. This region is an uncommon site of chromosomal breakage in malignancies and has not hitherto been reported as a breakpoint site in "jumping" translocations.

T cell receptor and immunoglobulin genes in hematologic malignancies

In this review, we discuss the structure, organization and activation of the immunoglobulin (Ig) and T cell receptor (TCR) genes and the use of DNA probes derived from these genes as tools to determine clonality and cell lineage in hemopoietic malignancies. We also examined briefly the participation of immunoglobulin and TCR genes in chromosomal aberrations present in many lymphoproliferative disorders, often involving protooncogenes and potentially of tumorigenic consequences.

Oncogene involvement in myelodysplasia and acute myeloid leukemia

The clonal malignancies of acute myeloid leukemia and the myelodysplastic syndromes are associated with numerous chromosomal and oncogenic abnormalities. Activation of oncogenes has been demonstrated, although there is little evidence that this alone causes malignant transformation of diploid cells as a consequence. Patterns of abnormalities can be seen as the patient progresses from myelodysplastic syndrome to acute myeloid leukemia, but no unique or invariant findings have been described. Chromosomal changes, with the exception of some translocations, are neither disease nor lineage specific. At this time the data provide good support for the multistep view of carcinogenesis, and there is indirect or circumstantial evidence for the presence of tumor suppressor genes on 5q and 7q. The continued study of these clonal hematological disorders will provide considerable insight into mechanisms of tumorigenesis and possibly may lead to new modes of therapy, for example, through altering the microenvironment, interfering with deranged signal transmission, or introducing antioncogenes.

Transfusion of ABO-incompatible platelets causing severe haemolytic reaction

Not infrequently clinical demand dictates that patients receive transfusions of ABO-incompatible platelets when there is a short supply of group-specific platelets. This carries a risk of causing a haemolytic reaction, as illustrated in the clinical case we report. In discussing this potential complication, we suggest a strategy for avoiding it.

Monoclonality in human T-cell disorders

The genes coding for the T-cell antigen receptor have recently been cloned. They have proven to be invaluable tools for the study of the molecular mechanisms governing T-cell recognition of foreign antigens associated with histocompatibility antigens. In addition, they have also provided sensitive means of detecting clonal cell populations and determining cell lineage. In this review we describe the general organisation of these genes, the results of their utilization in the analysis of hematological pathologies, and discuss the possible implications of the involvement of these genes in translocations observed in certain T-cell malignancies.

Athymic mice express a high level of functional gamma-chain but greatly reduced levels of alpha- and beta-chain T-cell receptor messages

T lymphocytes differentiate and mature in the thymus. It is here that thymocytes with reactivities to self antigens are eliminated and those with specificities to 'altered' self-major histocompatibility complex (MHC) gene products are positively selected. The selections are presumably carried out on the basis of their T-cell antigen receptors (TcR). The genes of the alpha- and beta-chain T-cell antigen receptors have been cloned. A third T-cell specific gene capable of undergoing somatic rearrangement has also been identified; the role of this third gene is not known. An order of expression of gamma, beta, then alpha is found during T-cell ontogeny. But although alpha- and beta-chain messages are often functional, gamma transcripts are rarely functional in thymocytes or mature T cells. To define the sequential order of expression of these genes further and to continue the search for a possible role for the TcR gamma gene products, we investigated the expression of 'functional' alpha-, beta- and gamma-chain transcripts in young athymic mice. These mice express an undetectable amount (less than one in 8 X 10(5) spleen messages) of 'full-length' alpha- and beta-chain T-cell receptor transcripts, but an increased level of expression of 'full-length' gamma chain messages. Nucleotide sequence analysis of four gamma complementary DNAs show that all four gamma transcripts sequenced are functional. These findings suggest that gamma gene products may be important in a prethymic or extrathymic pathway and may represent a second type of T-cell recognition, possibly in a lineage in which alpha and beta genes are not used.