Effectiveness of the COVID-19 vaccines on preventing symptomatic SARS-CoV-2 infections and hospitalizations in Southwestern Alaska, January-December 2021

The population in rural southwest Alaska has been disproportionately affected by COVID-19. To assess the benefit of COVID-19 vaccines, we analyzed data from the regional health system. We estimated vaccine effectiveness (VE) during January 16-December 3, 2021, against symptomatic SARS-CoV-2 infection after a primary series or booster dose, and overall VE against hospitalization. VE of a primary series against symptomatic infection among adult residents was 91.3% (95% CI: 85.7, 95.2) during January 16-May 7, 2021, 50.3% (95% CI, 41.1%-58.8%) during July 17-September 24, and 37.0% (95% CI, 27.8-45.0) during September 25-December 3, 2021; VE of a booster dose during September 25-December 3, 2021, was 92.1% (95% CI: 87.2-95.2). During the overall study period, VE against hospitalization was 91.9% (95% CI: 85.4-95.5). COVID-19 vaccination offered strong protection against hospitalization and a booster dose restored protection against symptomatic infection.

Antigen Test Positivity After COVID-19 Isolation - Yukon-Kuskokwim Delta Region, Alaska, January-February 2022

Isolation is recommended during acute infection with SARS-CoV-2, the virus that causes COVID-19, but the duration of infectiousness varies among individual persons. Rapid antigen test results have been correlated with detection of viable virus (1-3) and might inform isolation guidance, but data are limited for the recently emerged SARS-CoV-2 B.1.1.529 (Omicron) variant. On January 5, 2022, the Yukon-Kuskokwim Health Corporation (YKHC) recommended that persons with SARS-CoV-2 infection isolate for 10 days after symptom onset (or, for asymptomatic persons, 10 days after a positive nucleic acid amplification or antigen test result). However, isolation could end after 5-9 days if symptoms were resolving or absent, fever was absent for ≥24 hours without fever-reducing medications, and an Abbott BinaxNOW COVID-19 Ag (BinaxNOW) rapid antigen test result was negative. Antigen test results and associated individual characteristics were analyzed among 3,502 infections reported to YKHC during January 1-February 9, 2022. After 5-9 days, 396 of 729 persons evaluated (54.3%) had a positive antigen test result, with a declining percentage positive over time. In a multivariable model, a positive antigen test result was more likely after 5 days compared with 9 days (adjusted odds ratio [aOR] = 6.39) or after symptomatic infection (aOR = 9.63), and less likely after previous infection (aOR = 0.30), receipt of a primary COVID-19 vaccination series (aOR = 0.60), or after both previous infection and receipt of a primary COVID-19 vaccination series (aOR = 0.17). Antigen tests might be a useful tool to guide recommendations for isolation after SARS-CoV-2 infection. During the 10 days after infection, persons might be infectious to others and are recommended to wear a well-fitting mask when around others, even if ending isolation after 5 days.

Use of Rapid Antigen Testing for SARS-CoV-2 in Remote Communities - Yukon-Kuskokwim Delta Region, Alaska, September 15, 2020-March 1, 2021

Controlling the spread of SARS-CoV-2, the virus that causes COVID-19, in Alaska is challenging. Alaska includes many remote and isolated villages with small populations (ranging from 15 to >1,000 persons) that are accessible only by air from larger communities. Until rapid point-of-care testing became widely available, a primary challenge in the diagnosis of COVID-19 in rural Alaska was slow turnaround times for SARS-CoV-2 test results, attributable to the need to transport specimens to testing facilities. To provide more timely test results and isolation of cases, the Yukon Kuskokwim Health Corporation (YKHC) introduced Abbott BinaxNOW COVID-19 Ag rapid antigen test (BinaxNOW) on November 9, 2020, in the rural Yukon-Kuskokwim Delta region in southwestern Alaska. To evaluate the impact of implementing antigen testing, YKHC reviewed the results of 54,981 antigen and molecular tests for SARS-CoV-2 performed in the Yukon-Kuskokwim Delta during September 15, 2020-March 1, 2021. Introduction of rapid, point-of-care testing was followed by a more than threefold reduction in daily SARS-CoV-2 case rates during approximately 1 month before the introduction of COVID-19 vaccination. The median turnaround time for SARS-CoV-2 test results decreased by >30%, from 6.4 days during September 15-November 8, 2020, to 4.4 days during November 9, 2020-March 1, 2021 (p<0.001). Daily incidence decreased 65% after the introduction of BinaxNOW, from 342 cases per 100,000 population during the week of November 9 to 119 during the week of December 13 (p<0.001). These findings indicate that point-of-care rapid antigen testing can be a valuable tool in reducing turnaround times in rural communities where local access to laboratory-based nucleic acid amplification testing (NAAT) is not readily available and could thereby reduce transmission by facilitating rapid isolation of infected persons, contact tracing, and implementation of local mitigation strategies.

Young adults' intention to quit using JUUL

BACKGROUND

With research indicating some young audiences may desire to quit using JUUL, a high-nicotine e-cigarette, we sought to explore factors that may motivate them to quit.

METHODS

This sequential, mixed methods study included a cross-sectional online survey of college students (n = 631) followed by in-person interviews (n = 51) with survey participants. Data were collected March-April 2019. The survey asked about intention to quit using JUUL. A latent class analysis (LCA) identified participant groups who would quit for various reasons. Participants were also asked 'Can you be too old to JUUL?' during the survey. During the interviews, participants were provided preliminary survey findings and asked about their perceptions of the data. Interview participants were also asked about their expectations for future use of JUUL.

RESULTS

Four classes emerged from the LCA, indicating costs to self (i.e., harm to lungs/brain, price; 46.8%), financial costs (36.6%), all costs (e.g., social, monetary, health; 9.3%), and harm to self (7.3%) may have influenced our sample's decision to quit using JUUL. Interviewees affirmed desires to quit using JUUL, especially after leaving college. Only 27.19% of survey participants reported an age threshold for using JUUL (M = 31.8 years, SD = 10.0); however, several interviewees explained that although someone could not be too old to JUUL, it would be 'immature' or 'childish' for adults who were not trying to quit smoking to use JUUL socially.

DISCUSSION

Comprehensive tobacco control strategies such as taxing e-cigarettes, marketing campaigns, and nicotine cessation programs are needed to help nicotine dependent young adults quit using high-nicotine e-cigarettes.

Adult outcomes of childhood bronchiectasis

Recent literature has highlighted the importance of transition from paediatric to adult care for children with chronic conditions. Non-cystic fibrosis bronchiectasis is an important cause of respiratory morbidity in low-income countries and in indigenous children from affluent countries; however, there is little information about adult outcomes of childhood bronchiectasis. We reviewed the clinical course of 31 Alaska Native adults 20-40 years of age from Alaska's Yukon Kuskokwim Delta with childhood bronchiectasis. In patients with chronic suppurative lung disease, a diagnosis of bronchiectasis was made at a median age of 4.5 years by computerised tomography (68%), bronchogram (26%), and radiographs (6%). The patients had a median of 75 lifetime respiratory ambulatory visits and 4.5 hospitalisations. As children, 6 (19%) experienced developmental delay; as adults 9 (29%) experienced mental illness or handicap. Four (13%) patients were deceased, four (13%) had severe pulmonary impairment in adulthood, 17 (54%) had persistent or intermittent respiratory symptoms, and seven (23%) were asymptomatic. In adulthood, only five were seen by adult pulmonologists and most had no documentation of a bronchiectasis diagnosis. Lack of provider continuity, remote location and co-morbidities can contribute to increased adult morbidity. Improving the transition to adult care starting in adolescence and educating adult providers may improve care of adults with childhood bronchiectasis.

Evaluation of the Metasin assay for intraoperative assessment of sentinel lymph node metastases in breast cancer

AIMS

Sentinel lymph node (SLN) biopsy is the preferred surgical technique for staging the axilla in clinically node-negative breast cancer. Accurate intraoperative staging allows for the immediate performance of an axillary clearance in node-positive patients. We assessed the Metasin assay for the intraoperative analysis of SLNs in a prospective evaluation of 250 consecutive patients undergoing intraoperative SLN analysis at the Breast Unit, University Hospital, Southampton, UK.

METHODS

Metasin uses a quantitative reverse transcription PCR to detect two markers of metastasis: cytokeratin 19 (CK19) an epithelial marker and mammaglobin (MGB) a breast specific marker. Metasin results were compared with the results from routine paraffin block histopathology.

RESULTS

Metasin was robust, with a failure rate of <1%, and demonstrated excellent accuracy and reproducibility. The average turnaround time for the Metasin assay was 42 min, the largest variable being the number of nodes assayed. A total of 533 SLNs were evaluated with 75 patients testing positive for MGB and/or CK19. Based on the analysis of individual SLNs, the overall concordance between Metasin and histology was 92.3% (sensitivity 88.7%, specificity 92.9%). When adjusted for tissue allocation bias, the concordance was 93.8% (sensitivity 89.8%, specificity 94.6%). In this evaluation, 57/250 patients (23%) proceeded to axillary clearance based on Metasin results and were considered spared a second operative procedure.

CONCLUSIONS

Metasin has proven to be an accurate, reproducible and reliable laboratory test. The analysis time is acceptable for intraoperative use, and in comparison to routine histology demonstrates acceptable concordance, sensitivity and specificity.

Variations in COL15A1 and COL18A1 influence age of onset of primary open angle glaucoma

Primary open angle glaucoma (POAG) is a genetically and phenotypically complex disease that is a leading cause of blindness worldwide. Previously we completed a genome-wide scan for early-onset POAG that identified a locus on 9q22 (GLC1J). To identify potential causative variants underlying GLC1J, we used targeted DNA capture followed by high throughput sequencing of individuals from four GLC1J pedigrees, followed by Sanger sequencing to screen candidate variants in additional pedigrees. A mutation likely to cause early-onset glaucoma was not identified, however COL15A1 variants were found in the youngest affected members of 7 of 15 pedigrees with variable disease onset. In addition, the most common COL15A1 variant, R163H, influenced the age of onset in adult POAG cases. RNA in situ hybridization of mouse eyes shows that Col15a1 is expressed in the multiple ocular structures including ciliary body, astrocytes of the optic nerve and cells in the ganglion cell layer. Sanger sequencing of COL18A1, a related multiplexin collagen, identified a rare variant, A1381T, in members of three additional pedigrees with early-onset disease. These results suggest genetic variation in COL15A1 and COL18A1 can modify the age of onset of both early and late onset POAG.

Emergency capnography monitoring: comparing ergonomic design of intensive care unit ventilator interfaces and specific training of staff in reducing time to activation

Modern ventilators provide capnography monitoring in patients with tracheal tubes, in compliance with national and international recommendations. This technology is often not used when patients' lungs are non-invasively ventilated; however, it should be accessed immediately following tracheal intubation to confirm tube placement. This study assessed the effect of ventilation interface design on the speed with which capnography can be activated by comparing the Dräger Evita 4 and Dräger V500 before and after a specific training episode. We configured the V500 to have a capnography activation button on the front screen in contrast to the Evita 4 which requires a sequence of actions to access capnography monitoring. We used a randomised crossover design, measuring time to monitoring activation, and repeated the study after 3 months. Survival analysis showed significantly quicker activation associated with ventilator choice (V500, p < 0.0001) and training (p = 0.0058). The training improved activation speed with both machines, though this was only significant for the Evita 4 (p = 0.0097).

The histone deacetylase inhibitors vorinostat and romidepsin downmodulate IL-10 expression in cutaneous T-cell lymphoma cells

BACKGROUND AND PURPOSE

Vorinostat and romidepsin are histone deacetylase inhibitors (HDI), approved for the treatment of cutaneous T-cell lymphoma (CTCL). However, the mechanism(s) by which these drugs exert their anti-cancer effects are not fully understood. Since CTCL is associated with immune dysregulation, we investigated whether these HDI modulated cytokine expression in CTCL cells.

EXPERIMENTAL APPROACH

CTCL cell lines and primary CTCL cells were treated in vitro with vorinostat or romidepsin, or with STAT3 pathway inhibitors. Cell cycle parameters and apoptosis were analysed by propidium iodide and annexin V/propidium iodide staining respectively. Cytokine expression was analysed using QRT-PCR and elisa assays. STAT3 expression/phosphorylation and transcriptional activity were analysed using immunoblotting and transfection/reporter assays respectively.

KEY RESULTS

Vorinostat and romidepsin strongly down-regulated expression of the immunosuppressive cytokine, interleukin (IL)-10, frequently overexpressed in CTCL, at both the RNA and protein level in CTCL cell lines and at the RNA level in primary CTCL cells. Vorinostat and romidepsin also increased expression of IFNG RNA and decreased expression of IL-2 and IL-4 RNA, although to a lesser extent compared to IL-10. Transient exposure to vorinostat was sufficient to suppress IL-10 secretion but was not sufficient to irreversibly commit cells to undergo cell death. STAT3 pathway inhibitors decreased production of IL-10 and vorinostat/romidepsin partially decreased STAT3-dependent transcription without effects on STAT3 expression or phosphorylation.

CONCLUSIONS AND IMPLICATIONS

These results demonstrate that HDI modulate cytokine expression in CTCL cells, potentially via effects on STAT3. Immunomodulation may contribute to the clinical activity of HDI in this disease.

Targeted resequencing of a genomic region influencing tameness and aggression reveals multiple signals of positive selection

The identification of the causative genetic variants in quantitative trait loci (QTL) influencing phenotypic traits is challenging, especially in crosses between outbred strains. We have previously identified several QTL influencing tameness and aggression in a cross between two lines of wild-derived, outbred rats (Rattus norvegicus) selected for their behavior towards humans. Here, we use targeted sequence capture and massively parallel sequencing of all genes in the strongest QTL in the founder animals of the cross. We identify many novel sequence variants, several of which are potentially functionally relevant. The QTL contains several regions where either the tame or the aggressive founders contain no sequence variation, and two regions where alternative haplotypes are fixed between the founders. A re-analysis of the QTL signal showed that the causative site is likely to be fixed among the tame founder animals, but that several causative alleles may segregate among the aggressive founder animals. Using a formal test for the detection of positive selection, we find 10 putative positively selected regions, some of which are close to genes known to influence behavior. Together, these results show that the QTL is probably not caused by a single selected site, but may instead represent the joint effects of several sites that were targets of polygenic selection.

Monoclonality and oligoclonality of T cell receptor beta gene in angioimmunoblastic T cell lymphoma

Angioimmunoblastic T cell lymphoma (AILT) is an aggressive T cell lymphoma with an incidence of approximately 1-2% of all non-Hodgkin lymphoma. The detection of clonal T cell receptor (TCR) gene rearrangements helps in the diagnosis of T cell malignancies such as AILT, where morphological and immunohistological investigations are not always sufficient to reach a definitive diagnosis. TCR beta (TCRB) and TCR gamma (TCRG) gene rearrangements were analysed from 17 WHO-defined cases of AILT by PCR for the presence of TCR clonality. TCRB gene rearrangements were sequenced to identify molecular signature(s) common among this patient group. Monoclonal and oligoclonal TCRB and TCRG gene rearrangements were detected in all cases. BV17S1 was slightly over-represented compared to the use of other Vbeta gene segments; however, no preferential usage of J gene segment(s) was detected. The results of this study emphasise that TCR clonality and oligoclonality is a diagnostic feature of AILT and that BV17S1 is over-represented with no other common molecular findings.

Recurrent finding of the FIP1L1-PDGFRA fusion gene in eosinophilia-associated acute myeloid leukemia and lymphoblastic T-cell lymphoma

The FIP1L1-PDGFRA fusion gene has been described in patients with eosinophilia-associated myeloproliferative disorders (Eos-MPD). Here, we report on seven FIP1L1-PDGFRA-positive patients who presented with acute myeloid leukemia (AML, n=5) or lymphoblastic T-cell non-Hodgkin-lymphoma (n=2) in conjunction with AML or Eos-MPD. All patients were male, the median age was 58 years (range, 40-66). AML patients were negative for common mutations of FLT3, NRAS, NPM1, KIT, MLL and JAK2; one patient revealed a splice mutation of RUNX1 exon 7. Patients were treated with imatinib (100 mg, n=5; 400 mg, n=2) either as monotherapy (n=2), as maintenance treatment after intensive chemotherapy (n=3) or in overt relapse 43 and 72 months, respectively, after primary diagnosis and treatment of FIP1L1-PDGFRA-positive disease (n=2). All patients are alive, disease-free and in complete hematologic and complete molecular remission after a median time of 20 months (range, 9-36) on imatinib. The median time to achievement of complete molecular remission was 6 months (range, 1-14). We conclude that all eosinophilia-associated hematological malignancies should be screened for the presence of the FIP1L1-PDGFRA fusion gene as they are excellent candidates for treatment with tyrosine kinase inhibitors even if they present with an aggressive phenotype such as AML.

Improved reliability of lymphoma diagnostics via PCR-based clonality testing: — Report of the BIOMED-2 Concerted Action BHM4-CT98-3936

The diagnosis of malignant lymphoma is a recognized difficult area in histopathology. Therefore, detection of clonality in a suspected lymphoproliferation is a valuable diagnostic criterion. We have developed primer sets for the detection of rearrangements in the B- and T-cell receptor genes as reliable tools for clonality assessment in lymphoproliferations suspected for lymphoma. In this issue of Leukemia, the participants of the BIOMED-2 Concerted Action CT98-3936 report on the validation of the newly developed clonality assays in various disease entities. Clonality was detected in 99% of all B-cell malignancies and in 94% of all T-cell malignancies, whereas the great majority of reactive lesions showed polyclonality. The combined BIOMED-2 results are summarized in a guideline, which can now be implemented in routine lymphoma diagnostics. The use of this standardized approach in patients with a suspect lymphoproliferation will result in improved diagnosis of malignant lymphoma.

Lymphoproliferative disease in antibody deficiency: a multi-centre study

We have undertaken a retrospective study of antibody deficient patients, with and without lymphoma, and assessed the ability of specific polymerase chain reaction (PCR) primers to determine if the detection of clonal lymphocyte populations correlates with clinical and immunohistochemical diagnosis of lymphoma. We identified 158 cases with antibody deficiency presenting during the past 20 years. Paraffin-embedded biopsy specimens or slides were available for analysis in a cohort of 34 patients. Of these patients, 29 had common variable immunodeficiency, one X-linked agammaglobulinaemia, one X-linked immunoglobulin deficiency of uncertain cause and three isolated IgG subclass deficiency. We have confirmed that lymphoma in antibody deficiency is predominantly B cell in origin. Clonal lymphocyte populations were demonstrated in biopsies irrespective of histology (16/19 with lymphoma and 11/15 without). Isolated evidence of clonality in biopsy material is therefore an insufficient diagnostic criterion to determine malignancy. Furthermore, our data suggest that clonal expansions are rarely the result of Epstein-Barr virus-driven disease.

Diagnostic role of tests for T cell receptor (TCR) genes

Rapid advances in molecular biological techniques have made it possible to study disease pathogenesis at a genomic level. T cell receptor (TCR) gene rearrangement is an important event in T cell ontogeny that enables T cells to recognise antigens specifically, and any dysregulation in this complex yet highly regulated process may result in disease. Using techniques such as Southern blot hybridisation, polymerase chain reaction, and flow cytometry it has been possible to characterise T cell proliferations in malignancy and in diseases where T cells have been implicated in the pathogenesis. The main aim of this article is to discuss briefly the process of TCR gene rearrangement and highlight the disorders in which expansions or clonal proliferations of T cells have been recognised. It will also describe various methods that are currently used to study T cell populations in body fluids and tissue, their diagnostic role, and current limitations of the methodology.

Simultaneous analysis of T cell clonality and cytokine production in rheumatoid arthritis using three-colour flow cytometry

In this study we examined the cytokine production by T cells and TCRVbeta subsets in peripheral blood (PB) and synovial fluid (SF) from six RA patients and PB from 10 normal subjects, using three-colour flow cytometry. In two RA subjects we assessed T cell clonality by RT PCR using TCRBV family-specific primers and analysed the CDR3 (complementarity determining region 3) length by GeneScan analysis. A high percentage of IFN-gamma- and IL-2- producing cells was observed among the PB T cells in both the RA patients and normal controls and among the SF T cells in RA patients. In contrast, the percentage of T cells producing IL-4 and IL-5 was small among PB T cells in both RA patients and normal controls and among SF T cells in RA patients. There was no significant difference in the production of IFN-gamma, IL-2 and IL-5 between the two compartments (PB and SF); however, there were significantly more IL-4-producing cells in SF. Molecular analysis revealed clonal expansions of four TCRBV families in SF of two of the RA patients studied: TCRBV6.7, TCRBV13.1 and TCRBV22 in one and TCRBV6.7, TCRBV21.3 and TCRBV22 in the second. These expansions demonstrated cytokine expression profiles that differed from total CD3+ cells, implying that T cell subsets bearing various TCR-Vbeta families may have the potential to modulate the immune response in RA patients.

Modification of T-cell receptor Vbeta repertoire in response to allergen stimulation in peanut allergy

BACKGROUND

Peanut is one of the most common foods causing allergic reactions and is the most common cause of fatal and near-fatal food-related anaphylaxis. Little is known of the immunologic mechanisms that underlie peanut allergy.

OBJECTIVES

In this study we examined clonality of the T-cell response (TCR) to peanut in MHC class II identical, peanut allergy-discordant sibling pairs.

METHODS

Four sibling pairs were investigated. The TCR repertoire was analyzed before and after in vitro stimulation of PBMCs with crude peanut or PHA, as control for general/nonspecific reactivity. Eighteen TCR-Vbeta families were examined by flow cytometry. Where significant differences in incidence of particular TCR-Vbeta families were observed, PCR familyspecific cDNA amplification and gene scanning were performed.

RESULTS

After stimulation with peanut, no selective expansion of any TCR-Vbeta subpopulation was observed with flow cytometry, in either the peanut-allergic or nonallergic siblings, with the exception of 1 peanut-allergic subject who demonstrated a significant increase of TCR-Vbeta11(+) cells (0.3%-5.9% of the total CD3(+) cells). However, gene scanning revealed predominant single-size PCR products for TCRBV11 in all peanut-allergic subjects after peanut stimulation. TCRBV11 polyclo-nality was observed in allergic and nonallergic subjects before peanut stimulation and in nonallergic subjects after peanut stimulation. In comparison, all subjects, before and after stimulation with peanut, showed polyclonality for TCRBV2.

CONCLUSIONS

Our results argue for clonal or oligoclonal TCRs to crude peanut and indicate that changes in the TCRBV11 subpopulation are restricted to peanut-allergic subjects after stimulation with crude peanut allergen.

Molecular analysis reveals somatically mutated and unmutated clonal and oligoclonal B cells in T-cell-rich B-cell lymphoma

This paper describes the immunohistology and molecular genetics of 18 cases of T-cell-rich B-cell lymphoma (TCRBL). In all cases, the large B cells stained strongly for CD20, with more variable expression of CD79a, and were negative for CD30 and CD15. The majority of T cells were predominantly positive for TIA-1 and negative for CD57; a large population of histiocytes was present in all cases. Epstein-Barr virus (EBV)-coded RNA (EBER) was found in B blasts from four cases and in one case was present among the background lymphoid cells. IgH PCR products were generated in 16/18 cases and revealed clonal, oligoclonal and polyclonal PCR products in 12, two and two cases, respectively. In addition, TCRG clonal gene rearrangements were identified in two cases. TCRB gene rearrangements were polyclonal. Sequence analysis of seven cases with clonal/oligoclonal IgH gene rearrangements revealed functional sequences with predominant V(H)3 gene usage associated with various D genes and J(H)4 or J(H)6 gene segments. Four cases displayed varying degrees of replacement and silent mutations (1.8-21%), with one case exhibiting intraclonal heterogeneity; the distribution of mutations was indicative of antigen selection in three cases. The remaining three cases, including two cases with functional oligoclonal IgH rearrangements, harboured unmutated V region genes. The EBV-positive cases were associated with clonal, oligoclonal and polyclonal PCR products and with mutated and germline clonal sequences. These data indicate that TCRBL may be a heterogeneous entity associated with clonal and oligoclonal B cells derived from both germinal centre and naïve B cells.

Frequent T and B cell oligoclones in histologically and immunophenotypically characterized angioimmunoblastic lymphadenopathy

The identification of clonal rearrangements of T cell receptor (TCR) genes is central to the diagnosis of T cell lymphomas. However, in angioimmunoblastic lymphadenopathy (AILD), first described as a nonneoplastic proliferation associated with immunodeficiency, the heterogeneity of TCR and IgH gene rearrangements suggest that some cases may harbor multiple lymphoid clones. In this study we have isolated DNA from archival paraffin biopsy material from 22 cases of AILD identified on the basis of classical histological and immunohistochemical features with the aim of establishing the occurrence of clones and oligoclones, the frequency of TCR and immunoglobulin heavy chain (IgH) variable (v) gene use, and the relationship of these findings to the presence of Epstein-Barr virus. DNA extracted from the biopsies was amplified using the polymerase chain reaction (PCR) and sequenced to detect functional and nonfunctional gene rearrangements. Epstein-Barr virus-encoded short RNA species (EBERs) were detected using in situ hybridization combined with immunochemistry to identify the phenotype of the Epstein-Barr virus-infected cells. Fifty-seven clonal products were found in 20/22 patients: TCRgamma clonal products were identified in 16/22, TCRbeta clonal products in 16/22 and IgH clonal products in 6/22 cases. Oligoclonal PCR products were seen for TCR in 3/22 and for IgH in 3/22 cases. In one biopsy PCR products from all reactions were polyclonal. Sequence analysis revealed functional TCRgamma, TCRbeta, and IgH sequences in 6/12, 9/11, and 8/8 cases, respectively. Functional TCR and/or IgH oligoclones were detected in 6/20 (30%) cases. In addition, nonfunctional TCR and IgH sequences were found in 11 cases. EBERs were identified in 18/20 cases varying from occasional to 25 to 30% nuclei staining and were associated with both T and B cells, although the majority were of indeterminate phenotype. The presence of EBERs was not associated with all clonal IgH gene rearrangements but was associated with B cell oligoclones. Patterns of gene recombinations indicated that the majority of TCRgamma recombinations used GV1 and GJ1S3/2S3 genes. Six out of eleven cases used TCR BV4S1 or BV2S1 genes associated with various BJ and BD1/2 genes. No common IgH gene usage was identified, but 8 clones had varying degrees of replacement and silent mutations (0.6-10.1%), consistent with B cell clones having undergone somatic mutation in the germinal center, and 3 clones harbored unmutated V genes, consistent with naive B cells. Our data do not support the concept of AILD as a clearly defined peripheral T cell lymphoma (PTCL). Rather, they suggest that AILD as defined by histology and immunohistochemistry is either a heterogeneous entity or represents a lymphoproliferation associated with immunodeficiency in which clonal T cell or B cell proliferation may occur.

Interferon alpha treatment of molluscum contagiosum in immunodeficiency

A sister (aged 6 years) and brother (aged 8 years) presented four months apart with severe molluscum contagiosum. Both children demonstrated clinical and laboratory evidence of combined immunodeficiency. The extent of skin involvement by molluscum contagiosum precluded conventional treatment as well as intralesional interferon alpha (IFN alpha). Both subjects responded well to subcutaneous IFN alpha.

T cell receptor (TCR) Vbeta gene usage in bronchoalveolar lavage and peripheral blood T cells from asthmatic and normal subjects

T cells are thought to play an important regulatory role in asthma, but little is known about the T cell repertoire of the human lung or whether asthma is associated with any specific repertoire changes. Flow cytometry and MoAbs to TCR VB (TCRBV) families were used to quantify bronchoalveolar lavage (BAL) and blood T cells from normal and atopic individuals. Clonality was then assessed by polymerase chain reaction (PCR) amplification of cDNA and gene scanning using consensus and family-specific TCRBV primers and confirmed by sequence analysis. In addition, blood and BAL T cell populations were studied pre- and post-allergen challenge in four patients with allergic asthma. The majority of TCRBV families detected in blood by MoAb staining were also represented in BAL. While differences between BAL and blood populations were evident in each individual studied, these differences were not consistent between individuals or between CD4+ and CD8+ T cell subpopulations. These results are in broad agreement with other published studies, but in contrast to previous work we found a consistent difference between TCRBV7 family usage in blood and BAL in all individuals studied, and a consistently increased proportion of CD4+ BAL T cells bearing BV5S2/3 in asthmatics only. After allergen challenge, the pattern of TCRBV gene usage was largely unchanged as judged by flow cytometry. Gene scanning of PCR products generated from consensus VB primers revealed polyclonal lymphocyte populations in blood and BAL from all seven atopic individuals: in one normal tested polyclonal populations were found in blood and oligoclonal populations in BAL. Selected families amplified with family-specific primers BV5S2/3, BV6 and BV7 (chosen because of their predominance in BAL compared with blood) were more variable and revealed predominant polyclonal populations in blood and polyclonal or oligoclonal populations in BAL. In one asthmatic patient a clonal BV5S2 family was found in BAL. Following allergen challenge there were no significant changes in polyclonality/oligoclonality/clonality in three cases, but in one case a clonal BV5S2 population was found after challenge, that had not been evident beforehand. The lung T cell repertoire is thus broadly representative of blood T cells, but shows population differences that may result from response to persistent exposure to airborne antigens common to normal and atopic individuals. Oligoclonal TCRBV family expansion appears to be primarily lung-specific but independent of atopic asthma, although our challenge data in one case support the concept that clonal populations may follow local allergen challenge. These data are consistent with selection and amplification of specific T cell families in the lung in response to local antigenic exposure.

Modification of IgH PCR clonal analysis by the addition of sucrose and cresol red directly to PCR reaction mixes

Diagnostic immunoglobulin (Ig) polymerase chain reaction (PCR) clonality analyses need to be simple, reproducible, and rapid. Sucrose and cresol red (gel loading buffer reagents) were added to a routine IgH PCR reaction mix to obviate the need for adding gel loading buffer separately after PCR amplification. Not only did this decrease the time spent after PCR analysis but also gave similar or enhanced IgH PCR product intensity compared with normal IgH PCR conditions on polyacrylamide gel electrophoresis. This procedure was easily adapted to routine PCR analysis without the need for further manipulations or optimisation of the PCR reaction mix, and it increased the reproducibility and specificity of the IgH PCR products.

Molecular detection of a B cell clone in a case of PTCL in the absence of T cell clonality

In this paper we document a case of peripheral T cell lymphoma (PTCL) that exhibited variable T cell histology at presentation and follow-up. Southern blot analysis for T cell receptor (TCR) and immunoglobulin (Ig) receptor gene rearrangements failed to reveal clonal T or B cell populations. TCR gamma (TCRG) and beta (TCRB) chain gene polymerase chain reaction (PCR) amplification of DNA isolated from biopsies was also consistent with polyclonal T cell populations, however Ig PCR revealed clonal Ig rearrangements in follow-up biopsies but not in the presentation biopsy. There was no histological evidence for a neoplastic B cell population in these biopsies although occasional EB virus positive blasts were present. The significance of a cryptic B cell clone is unknown but suggests a relationship with the proliferating polyclonal T cells in this case of PTCL. These data reflect the complexity of PTCL with implications for treatment and patient management.

Oligoclonal populations of T and B cells in a case of angioimmunoblastic T-cell lymphoma predominantly infiltrated by T cells of the VB5.1 family

AIMS

Immunohistological and molecular characterisation of a case of peripheral T-cell lymphoma (PTCL) of angioimmunoblastic T-cell lymphoma (AILD) type.

METHODS

Frozen and paraffin wax sections of the diagnostic lymph node were stained with a panel of T- and B-cell lineage monoclonal antibodies. DNA was isolated from the paraffin wax embedded biopsy material for T-cell receptor (TCR) and immunoglobulin (Ig) PCR amplification, and resultant PCR products were cloned and sequenced.

RESULTS

Immunohistological analysis of the presenting lymph node was consistent with an extensive infiltrate of pleomorphic CD3+CD8+ lymphocytes. Most (>80%) of these infiltrating CD3+ cells were also positive for the TCR VB5.1 gene family product, and were shown to be oligoclonal by TCRB PCR amplification and sequencing. Three oligoclones of B cells were also demonstrable by PCR amplification with Ig heavy chain primers and sequencing, a finding at variance with the diagnosis of AILD.

CONCLUSIONS

These data demonstrate the complexity and heterogeneity of PTCL which require extensive histological examination and molecular characterisation.

Arthropathy, leucopenia and recurrent infection associated with a TcR gamma delta population

This report documents the presence of clonal gamma delta T-cell receptor (TcR) population in the blood of a patient who presented with an arthropathy of undetermined cause, leucopenia and splenomegaly. There was no evidence for lymphoid malignancy clinically or at post-mortem. The phenotype and genotype of the clonal T-cell population were not associated with the predominant TcR delta rearrangement found in peripheral blood gamma delta cells, but were similar to those found in gamma delta TcR cells infiltrating rheumatoid synovium. The data indicate the presence of a monoclonal population of gamma delta cells TcR cells which in the face of continued immunosuppression behaved benignly. The case may represent a cytomorphologically atypical example of the large granular lymphocytes, neutropenia and arthropathy syndrome/lymphoproliferative disease of granular lymphocytes and, although the patient's clinical features were not 'classical', rheumatoid arthritis (RA) may have been the underlying primary disorder.

Isolation of nucleic acid from paraffin embedded tissue for PCR amplification and sequencing of TcR V beta genes

PCR analysis of DNA and RNA from fresh and frozen tissue is now a routine practice in most laboratories. Furthermore DNA extracted from paraffin embedded tissue is routinely used for clonality studies and for HLA typing. However the use of RNA from paraffin embedded tissue is more problematical due to degradation and only short sequences are suitable for amplification. In this report we examine the suitability of extracted nucleic acid from paraffin embedded tissue for the PCR amplification of TcR V beta genes and sequencing of resultant PCR products.

Detection of T-cell receptor beta chain mRNA in frozen and paraffin-embedded biopsy tissue using digoxigenin-labelled oligonucleotide probes in situ

In situ hybridization techniques using a cocktail of digoxigenin-labelled T-cell receptor (TcR) constant (C) region beta oligonucleotide probes were used to detect TcR beta mRNA in frozen and paraffin-embedded tissue sections. The specificity of the C beta cocktail was confirmed by Northern blot analysis. The TcR C beta cocktail successfully hybridized to T cells in frozen and paraffin-embedded tissue obtained from patients with inflammatory arthropathies, B- and T-cell non-Hodgkin's lymphoma (NHL), and reactive tonsillitis, and showed staining patterns comparable to those obtained by conventional immunohistological detection of T cells. This is the first report of in situ studies using labelled TcR C beta oligonucleotide probes and may indicate the feasibility of investigating clonal T-cell populations using digoxigenin-labelled clonospecific probes in clinical samples in situ.

Effect of granulocyte-macrophage colony-stimulating factor on oral mucositis after hematopoietic stem-cell transplantation

PURPOSE

Oral mucositis following high-dose chemotherapy may result in systemic infection and airway compromise, and the severity of oral mucositis may be dose-limiting. Here we investigate the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF), which significantly shortens duration of neutropenia after hematopoietic stem-cell transplantation (HSCT) on oral mucositis.

PATIENTS AND METHODS

Thirteen children undergoing HSCT were prepared with etoposide (VP-16), thiotepa (TT), and total-body irradiation (TBI), and 13 with VP-16, TT, and cyclophosphamide (CPM). Following transplantation, 14 patients received GM-CSF at a dose of 125 micrograms/m2/d by continuous intravenous infusion (six prepared with VP-16, TT, and TBI, and eight prepared with VP-16, TT, and CPM), and 12 patients received no growth factor.

RESULTS

Mucositis was more severe and persisted longer in patients prepared with the TBI-containing regimen. For this regimen, the duration of severe oral mucositis was shortened by the administration of GM-CSF, although the severity of mucositis was unaffected. No statistically significant effect of GM-CSF could be shown in patients who received VP-16, TT, and CPM. The incidence of positive fungal oral or blood cultures did not appear different whether patients received GM-CSF or not.

CONCLUSION

For patients undergoing stomatotoxic HSCT regimens, GM-CSF may reduce the duration of oral mucositis, but is unlikely to effect the severity of oral mucositis or risk of airway compromise, and the severity of mucositis is likely to remain dose-limiting.

Polymerase chain reaction amplification analyses of clonality in T-cell malignancy including peripheral T-cell lymphoma

Clonality in T-cell malignancy was investigated using T-cell receptor (TcR) V beta 1-20 family primers and polymerase chain reaction amplification (PCR) of cDNA prepared from tissue biopsies and blood involved with tumour. Secondary PCR amplification of the VDJ joints of primary PCR products was performed to distinguish clonal from polyclonal products, and clonal V beta gene products were confirmed by direct PCR sequencing in the majority of cases. In eight T-cell malignancies including T-cell acute lymphoblastic leukaemia (T-ALL) and T-cell chronic lymphocytic leukaemia (T-CLL) shown to be clonal by Southern blot analysis, one or two primary PCR products were identified and shown to be clonal. In five cases of peripheral T-cell lymphoma (PTCL) all V beta 1-20 families were identified after primary PCR amplification, and clonal products were identified in two cases after secondary amplification; TcR V beta clonal families could not be demonstrated in the remaining three cases. These data were in agreement with previous Southern blot analysis of these cases, and confirmed the presence of reactive T cells in PTCL as well as providing further evidence for the genotypic heterogeneity of this entity. In the remaining case, a blood lymphocytosis, primary PCR amplification produced predominant TcR V beta 6 and V beta 12 family products, of which the V beta 6 family proved clonal after secondary PCR amplification. There was no evidence for overrepresentation of TCR V beta families by the tumour populations in this study, furthermore the data confirm the involvement of reactive cells in T-cell malignancy and the genetic heterogeneity of PTCL.

Use of a retinoblastoma gene probe to investigate clonality in Richter's syndrome

A 69-year-old woman presented with Rai stage 0 chronic lymphocytic leukemia. Ten years later she developed a diffuse centroblastic lymphoma involving the stomach. The surface membrane phenotype of the CLL cells was MD lambda while that of the large cell lymphoma (LCL) cells was MD kappa. The two populations had different heavy and kappa light chain rearrangements. Cytogenetic analysis of the CLL cells showed a deletion involving chromosome 13, band q14, but was unsuccessful in the LCL cells. However, use of a probe (p68 RS2.0) which recognizes a variable number tandem repeat sequence in the retinoblastoma gene, localized to chromosome 13q14, showed two alleles in the LCL cells but only one in the CLL cells. These data suggest that in this case of Richter's syndrome the CLL cells and the LCL cells are clonally distinct.

Genotypic heterogeneity of node based peripheral T-cell lymphoma

PTCL represents a diverse group of histological entities that defy classification schemes based on normal T cell differentiation, differ in their clinical presentation and behave unpredictably. Genetic analyses of this phenotypically heterogeneous group have clearly shown that histologically defined PTCL may be subdivided on the basis of clonal gene rearrangements. The absence of clonal gene rearrangements in a significant proportion of PTCL cases has increased the complexity of classification. The data presented in this review suggest that a molecular classification would allow true reflection of PTCL aetiology, but carefully coordinated studies are required to evaluate the clinical usefulness of such a classification scheme.

Use of paraffin wax embedded bone marrow trephine biopsy specimens as a source of archival DNA

AIMS

To evaluate the use of DNA extracted from paraffin wax embedded trephine biopsy specimens as a source of archival nucleic acid for Southern hybridisation studies and polymerase chain reaction (PCR) amplification.

METHODS

DNA was extracted simultaneously from paraffin wax embedded bone marrow trephine and lymph node biopsy specimens after incubation of tissue sections for one to five days in lysis mix and proteinase K with periodic sampling. DNA from 10 trephine biopsy specimens was subjected to PCR amplification using HLA-DPB primers to determine whether the extracted nucleic acid was of sufficient quality to permit amplification.

RESULTS

For most specimens the greatest yield of high molecular weight DNA was seen after five days' incubation. Unlike lymph node material the quality of extracted nucleic acid and the quantity obtained from trephines was insufficient for Southern blot analysis. PCR amplification using HLA-DPB primers yielded positive results in six out of 10 trephine biopsy specimens.

CONCLUSIONS

DNA extracted from paraffin wax embedded trephine biopsy specimens is largely degraded and unsuitable for Southern analysis but serves as a useful source of archival nucleic acid for PCR amplification.

T-cell receptor variable (V) gene usage by lymphoid populations in T-cell lymphoma

A panel of monoclonal antibodies specific for TcR V gene families was used to study TcR V region expression in 28 cases of malignant and reactive T-cell expansions including four cases of mixed cellularity Hodgkin's disease (HD) and five reactive cases. TcR V beta 5 gene products were represented in three cases of lymphoblastic malignancy (V beta 5.1, V beta 5.2) and two cases of peripheral T-cell lymphoma (PTCL) (V beta 5.1). In the PTCL cases, the expanded family was found in the absence of clonal TcR gene rearrangements and in one of these cases with Ig JH and Ck clonal gene rearrangements consistent with the presence of a phenotypically and histologically undetectable clonal B-cell population. In a third PTCL case not investigated for genotype, the TCR V alpha 12 family was overrepresented. Expanded TcR V alpha 2 and V beta 5.1 families were identified in HD and V beta 8 and V beta 5.2/V beta 5.3 families in a reactive lymph node and CD3 and CD8-positive blood lymphocytosis respectively. Further study of PTCL and related entities are needed to establish whether expanded TcR families are common in those cases that fail to exhibit clonal TcR gene rearrangement.

Is adult-onset coeliac disease due to a low-grade lymphoma of intraepithelial T lymphocytes?

Enteropathy-associated T-cell lymphoma commonly presents with malabsorption, and debate continues as to whether adult-onset coeliac disease (CD) is itself a form of low-grade lymphoma. A 59-year-old man with adult-onset CD required resection of a segment of oedematous jejunum. Histological examination of this tissue revealed an intense intraepithelial lymphocytosis. Immunophenotypic (CD3-, CD4-, CD8-, CD34-, and CD45 RO-) and cytogenetic (deletion of the Y chromosome and chromosome 9) abnormalities were found, together with monoclonal T-cell-receptor gene rearrangements. Some patients with adult-onset CD may have low-grade lymphoma from the outset of their illness.

Chronic myelomonocytic leukaemia associated with T cell receptor delta gene rearrangement

Morphological, immunophenotypic, and genetic analyses were carried out on peripheral blood, bone marrow, and pharyngeal biopsy material from a patient with chronic myelomonocytic leukaemia (CMML). Morphological analysis of bone marrow was diagnostic of CMML; immunophenotypic analysis of peripheral blood and bone marrow were negative for B and T cell antigens, and immunochemistry performed on the pharyngeal extramedullary infiltrate showed the presence of large monocytoid cells which stained positively for muramidase. Genotypic analysis, however, showed clonal rearrangement of the T cell receptor (TCR) delta chain gene, a marker of T cell or, less commonly, B cell lymphoid neoplasms. Other TCR genes, beta and gamma, were germline in all tissues examined. TCR delta is rearranged in precursor B cell and most T lymphoid neoplasms. A small proportion of cases (10%) of acute myeloid leukaemia (AML) also show rearrangement of the TCR delta gene. To date TCR delta rearrangement has not been described in CMML. The aberrant TCR delta rearrangement shown in this patient with CMML provides further evidence of the clonal nature of this disorder.

Variable X-chromosome DNA methylation patterns detected with probe M27 beta in a series of lymphoid and myeloid malignancies

In this study the X chromosome probe M27 beta was used to investigate DNA methylation at the DXS255 locus and hence X inactivation status and determination of tumour clonality in blood, bone marrow and biopsy tissue involved with morphologically and phenotypically defined lymphoid and myeloid disease from 14 female patients along with uninvolved bone marrow from two control individuals. Thirteen out of 16 individuals (81%) were restriction fragment length polymorphism (RFLP) heterozygous for DXS255. DNA methylation status could not be assessed in the three DXS255 homozygous individuals. In eight DXS255 heterozygous individuals clonality was clearly demonstrated using M27 beta and in six of these cases independent analysis using T cell receptor (TcR) and immunoglobulin (Ig) gene probes confirmed the presence of clonal tumour cell populations. In the two controls, polyclonality was inferred from M27 beta probe analysis. In the remaining three cases (all acute lymphoblastic leukaemia (ALL)) both DXS255 X chromosome sequences appeared to be methylated. Clonality in these cases was demonstrated by TcR or Ig monoclonal gene rearrangements. These data demonstrate the value of the M27 beta probe for determining tumour clonality in a number of cases with lymphoid and myeloid disease but indicate that there may not always be a complete correlation between DNA methylation. X inactivation status and tumour clonality in certain lymphoid neoplasms, restricting the use of this probe in clonality studies. Correlations between DNA methylation, X inactivation status and stage of normal and neoplastic T and B cell development require further investigation.

Histologic, immunophenotypic and genotypic analyses of bone marrow trephines from patients with non-Hodgkin's lymphoma

Marrow involvement in 20 patients with non-Hodgkin's lymphoma (NHL) were studied by histology, immunophenotypic and genotypic methods. Eighteen of these trephines were histologically involved with recognizable lymphomatous infiltrates and five of these were the primary disease site. In the remaining two cases (with histologically involved lymph nodes) the trephines were uninvolved with tumour. Three B-cell cases expressing surface immunoglobulin (sIg) and/or CD37 and one case not analysed phenotypically showed Ig gene rearrangements. The two remaining cases with B NHL showed no gene rearrangements, however, in one of these the trephine was histologically uninvolved with tumour. Twelve out of 14 T-cell cases were characterized by variable or absent expression of one or more T-cell antigens from the tumour population, one case was negative for all T-cell antigens and the remaining case was not histologically involved with tumour. All three lymphoblastic lymphomas and only 4/11 peripheral T-cell lymphomas (PTCL) cases revealed T-cell receptor (TcR) gene rearrangements. One of the latter cases also exhibited Ig JH gene rearrangements. This study demonstrates the usefulness of bone marrow trephines (BMT) in histologic, phenotypic and genotypic analyses. However, although genotypic data confirm clonality in B NHL and the lymphoblastic lymphomas there was genotypic heterogeneity within the PTCL group.

Clonality of T cell and phenotypically undefined lymphoid neoplasms: the value of genotypic analyses

The value of genotypic analysis for routine assessment of leukaemia and lymphoma was shown by the findings in a selected series of 30 cases. T cell receptor (TcR) gene rearrangements were observed in six out of nine cases of CD3+ CD8+ lymphocytoses and provided clear evidence for clonality in this group. The T cell proliferations in two of the remaining cases masked B cell lymphocytic leukaemia and hairy cell leukaemia, while in the third case no cause was found for the polyclonal proliferation. Heterogeneity of phenotype and genotype were observed in peripheral T cell lymphomas: one out of six cases showed TcR gene rearrangement, one case retained its germline configuration, a further case masked B cell lymphoma and the remainder were polyclonal. Genotypic analysis was helpful in the analysis of a tumour of mixed T cell and myeloid phenotype which was shown to be germline for TcR and immunoglobulin genes, consistent with a myeloid origin. Two histiocytic tumours were found to have clonal rearrangement of TcR genes. Nine out of 11 B cell tumours showed immunoglobulin gene rearrangement. It is concluded that genetic analyses are useful in the analysis of T cell, histiocytic, and B cell tumours in which an immunoglobulin phenotype cannot be defined.

Orbital cellulitis: review of 23 cases from Saudi Arabia

We studied a total of 23 patients with orbital cellulitis and/or orbital abscess over a period of four years in Saudi Arabia. The study showed a high rate of abscess formation (12/23) and surgical intervention (17/23). Twelve out of 23 patients were 18 or more years of age. Furthermore, 12 of 23 (52%) patients had blind eyes on admission and remained blind after treatment, and one patient died of cavernous sinus thrombosis. Only 7/23 (30%) had a predisposing cause of primary sinus disease. This study of orbital cellulitis in a developing country presents a variation in disease pattern from previous reports and suggests that delay in the initiation of antibiotic therapy may lead to serious complications which may be life threatening. The course and outcome of orbital cellulitis may vary, depending on the predisposing factor, time of onset, associated systemic disease, or delay in initiation of treatment.

Detection of kidney reactive antibodies at crossmatch in renal transplant recipients

We have investigated retrospectively sera from 70 renal allograft recipients for the presence of antibodies binding to a preanastomosis biopsy of the donor kidney by an indirect immunoperoxidase technique. All recipients had a negative T cell lymphocytotoxic crossmatch. A positive immunoperoxidase crossmatch for kidney-reactive antibodies was seen in 13/70 (18.6%) recipients--6 reacting with endothelium, 4 with epithelium, and 3 with both cell types. Neither the presence of these antibodies nor their pattern of staining correlated with recipient graft outcome. Following transplantation endothelial reactive antibodies developed in 15/43 (35%) patients, whereas tubular epithelial antibodies occurred in 5/43 (12%). The antibodies were persistent and accompanied graft failure in 10/14 (71%) patients, while transient antibodies were only associated with graft failure in 2/12 (17%) recipients. Development of lymphocytotoxic antibodies did not correlate with the presence of renal reactive antibodies or eventual graft outcome. Smooth muscle and antinuclear antibodies in recipient sera prior to transplantation were associated with improved graft survival. Eluates of 8/14 rejected grafts confirmed the presence of renal reactive antibodies, with patterns of staining similar to those observed in recipient sera. Antibodies in 7/8 recipients were shown by absorption studies to have HLA class I and/or II specificity, the remaining recipient having proximal tubular brush border antibodies.