Remarkable 107-year-old kidney with a 49-year of long-term allograph survival through continuous azathioprine monotherapy.

BACKGROUND: The main goal of kidney allograft transplantation is to improve survival in patients with end-stage kidney failure. Herein, we report a 49-year long-term allograft survival with non-identical human leukocyte antigens (HLA). The purpose of this study was to report the successful clinical outcome of 49 years of transplant survival in a 79-year-old patient with a 107-year-old kidney undergoing continued immunosuppressive monotherapy. MATERIAL AND METHODS: The patient was evaluated clinically and immunologically with HLA typing and anti-HLA antibodies before transplantation. Post-transplant, the patient's clinical and immunological survival were monitored for 49 years. The state of the chimerism was assessed using the polymerase chain reaction to amplify 24 short tandem repeats using a DNA thermocycler and DNA analyzer. RESULTS: The patient and donor were haploidentical and the patient was treated with azathioprine monotherapy. Donor-specific antibodies were detected only for the HLA-DPB1* 03:01 mismatch. This patient developed multiple skin tumors 26 years after transplant, which were successfully treated with topical therapy or surgical removal. The patient developed an intestinal adenocarcinoma 43 years after kidney transplantation, which was surgically removal; six years later, adenocarcinoma was diagnosed in a finger, followed by axillar and hepatic metastases. After 49 years of graft survival of a kidney of 107 years old in a patient with 79 years of age, the patient's health worsened with severe dehydration, anemia, and bacterial infection. The patient was hospitalized with a serum creatinine level of 3.45 mg/dL, urea level of 188 mg/dL, and estimated glomerular filtration rate of 22 mL/1.72 m2; septicemia developed and was treated with antibiotics. The patient had poor clinical progress, was intubated, and later died due to septic shock. CONCLUSIONS: To the best of our knowledge, this is the first case of a 107-year-old kidney, transplanted into a recipient who was treated with azathioprine monotherapy for 49 years.

Nova mutação no gene STAT1 associada com candidíase mucocutânea crônica / New STAT1 gene mutation associated with chronic mucocutaneous candidiasis

Mutações no gene STAT1 (signal transducer and activator of transcription 1) têm sido identificadas como responsáveis pela maioria dos casos sindrômicos da candidíase mucocutânea crônica com herança autossômica dominante (AD). Nesse artigo, descrevemos uma menina de 7 anos que apresentou candidíase da mucosa oral e unhas, além de infecção disseminada da pele e couro cabeludo por Microspora gipseum. Recentemente, a paciente foi diagnosticada e tratada de meningite por Cryptococcus neoformans. Na família não existem outros casos de candidíase. A avaliação imunológica incluiu a detecção de subpopulações de linfócitos (CD3, CD4, CD8, CD20 e células NK), assim como a dosagem de IgG, IgA, IgM e IgE, subclasses de IgG e autoanticorpos. Excluindo-se discreta diminuição de CD3, CD4, CD8, NK e leve aumento de IgG1, os demais exames estiveram dentro da normalidade. O sequenciamento do exoma detectou uma rara mutação em heterozigose no exon 14 do domínio de ligação do DNA (DNA-binding domain) do gene STAT1, ocasionando um provável ganho de função (GOF) responsável pela doença (Gly384Asp). Essa variação foi também identificada pelo sequenciamento de Sanger, não estando reportada nos bancos de dados públicos e apresentando elevado potencial de dano (índice CADD=32). Será interessante contarmos com informações clínicas e estudos com outros pacientes para conhecermos mais essa mutação patológica. Além da apresentação do caso, discutiremos as formas de tratamento existentes.

STAT1 (signal transducer and activator of transcription 1) gene mutations have been identified as responsible for most syndromic cases of chronic mucocutaneous candidiasis with autosomal dominant (AD) inheritance. In this article, we described a 7-year-old girl who presented with candidiasis of the oral mucosa and nails, as well as disseminated infection of the skin and scalp caused by Microsporum gypseum. Recently, the patient was diagnosed and treated for Cryptococcus neoformans meningitis. There are no other cases of candidiasis in the family. The immunological evaluation consisted of detection of subpopulations of lymphocytes (CD3, CD4, CD8, CD20, and NK cells), as well as measurement of IgG, IgA, IgM, and IgE, IgG subclasses, and autoantibodies. Excluding a slight decrease in CD3, CD4, CD8, NK and a minimal increase in IgG1, the others were within normal limits. Exome sequencing detected a rare heterozygous variation in exon 14 of the DNA-binding domain of the STAT1 gene, causing a probable gain of function (GOF) responsible for the disease (Gly384Asp). This variation was also identified by Sanger sequencing, but it was not reported in public databases and had a high potential for damage (Combined Annotation-Dependent Depletion [CADD] score = 32). Having clinical information and conducting studies of other patients will be helpful to learn more about this pathological mutation. In addition to the presentation of the case, we will discuss the existing forms of treatment.

Infecção por SARS-CoV-2 em paciente com agamaglobulinemia ligada ao X tratado com altas doses de imunoglobulina endovenosa e plasma de convalescente / SARS-CoV-2 infection in a patient with X-linked agammaglobulinemia treated with high doses of intravenous immunoglobulin and convalescent plasma

A pandemia pelo vírus SARS-CoV-2 atingiu adultos, crianças e penalizou indivíduos idosos e com comorbidades como diabetes, doença cardíaca, hipertensão e obesidade. A maioria dos infectados são assintomáticos ou têm sintomas leves, entretanto 15% podem apresentar pneumonia e 5% síndrome respiratória aguda grave. Apresentamos um caso de agamaglobulinemia ligada ao X (XLA) em paciente masculino de 27 anos que se infectou com SARS-CoV-2. Os pacientes com XLA não possuem linfócitos B e não produzem anticorpos devido a uma mutação no gene Bruton tirosino-quinase (BTK), responsável pela maturação dos linfócitos B. Ele infectou-se e foi internado em hospital de Ivoti/RS. A evolução da pneumonia foi rápida, necessitando transferência para o Hospital de Clínicas de Porto Alegre (HCPA) no 10° dia de evolução. Iniciou com infusão de imunoglobulinas, tendo utilizado o total de 400 gramas devido ao intenso catabolismo da IgG, mantendo-se sua concentração entre 700-900 mg/dL. Necessitou de ventilação mecânica, oxigenação por membrana extracorpórea (ECMO) e hemodiálise. Foi administrado plasma de convalescente (PC), 300 mL, por duas vezes, com melhora clínico-radiológica e retirada da ventilação mecânica. Piorou e repetiu outras 4 infusões de PC (total de 1717 mL), negativando o vírus na orofaringe (RT-PCR). Em 3 ocasiões teve sepse, debelada rapidamente. Apresentou anemia, com necessidade de transfusão frequente. Identificou-se linfopenia de CD3, CD4, CD8, NK e ausência de linfócitos B. A linfopenia foi revertida com a recuperação clínica e a alta hospitalar aconteceu no 70° dia de internação.

The SARS-CoV-2 pandemic has affected adults and children and penalized older people and those with comorbidities such as diabetes, heart disease, hypertension and obesity. Most of those infected are asymptomatic or have mild symptoms, but 15% may have pneumonia and 5% acute respiratory distress syndrome. We report a case of X-linked agammaglobulinemia (XLA) in a 27-yearold man who was infected with SARS-CoV-2. XLA patients do not have B lymphocytes and do not produce antibodies because of mutations in the Bruton tyrosine-kinase gene, responsible for the maturation of B cells. This patient was infected and then admitted to a hospital in Ivoti, southern Brazil. Pneumonia progressed rapidly, requiring transfer to the Hospital de Clínicas de Porto Alegre on the 10th day. Intravenous immunoglobulin infusions were initiated, using a total of 400 grams because of an intense catabolism of IgG, and the concentration was kept around 700- 900 mg/dL. Mechanical ventilation, extracorporeal membrane oxygenation and hemodialysis were necessary. Convalescent plasma (CP) was administered (2x300 mL) and then followed by clinical and radiological improvement and interruption of mechanical ventilation. Then he got sicker and had to return to invasive support and received 4 extra CP infusions (total of 1717 mL), until a negative reverse-transcriptase polymerase chain reaction (RT-PCR) for SARS-CoV-2 was obtained. On 3 occasions he had sepsis, promptly managed. He had anemia, requiring frequent transfusion, and lymphopenia (CD3, CD4, CD8, NK), with absence of B lymphocytes. Lymphopenia was reverted during recovery, and he was discharged from the hospital on the 70th day.

Neutropenia aloimune neonatal em gêmeas idênticas / Neonatal alloimmune neutropenia in identical twins

A neutropenia aloimune neonatal (NAN) é uma patologia causada pelo antagonismo imunológico, como a doença hemolítica do recém-nascido ou a trombocitopenia aloimune neonatal, mas relacionada aos neutrófilos, em vez de glóbulos vermelhos ou plaquetas. Descreveremos um caso clínico de duas gêmeas idênticas nascidas a termo, com Apgar de 8 e 9, sendo que após algumas horas do nascimento apresentaram febre. Um exame de sangue revelou neutropenia grave que resultou em sepse. O diagnóstico da NAN foi realizado clinicamente e por testes de histocompatibilidade. A prova cruzada por citometria de fluxo foi positiva, usando soro da mãe e suspensões celulares (granulócitos e linfócitos) das gêmeas e do pai. Este teste não fornece informações sobre para qual sistema genético os anticorpos foram positivos, se contra os antígenos específicos de neutrófilos humanos (HNA) ou contra os antígenos leucocitários humanos (HLA). Para o esclarecimento, realizamos o teste de aglutinação de granulócitos (GAT) com um painel de doadores fidelizados e com antígenos HNA1-5 conhecidos, utilizando o soro materno como reagente. Foi também realizada a pesquisa de anticorpos anti-HLA e anti-HNA no soro materno. Os genótipos HLA e HNA foram identificados, permitindo conhecer as especificidades dos anticorpos maternos contra os antígenos dos neutrófilos do marido e das filhas. O diagnóstico de NAN não é realizado na maioria dos hospitais de nosso país e do exterior, devido à dificuldade de execução dos testes de histocompatibilidade, no entanto a prova cruzada por citometria de fluxo pode facilmente ser implantada nos laboratórios clínicos, sendo que está descrita detalhadamente nesse caso clínico.

Neonatal alloimmune neutropenia (NAN) is a disease caused by immunological antagonism, such as hemolytic disease of the newborn or neonatal alloimmune thrombocytopenia, but related to neutrophils rather than to red blood cells or platelets. We will describe a clinical case of two identical twins born with Apgar 8 and 9 that started with fever few hours after delivery. A blood test revealed severe neutropenia, which was followed by sepsis. The diagnosis of NAN was done clinically and by histocompatibility testing. Flow cytometry crossmatch was positive, using mother serum and cell suspensions (granulocytes and lymphocytes) from the twin girls and from the father. This test did not provide information about the genetic system for which the antibodies are positive, if against human neutrophil antigens (HNA) or human leucocyte antigens (HLA). To clear this, the granulocyte agglutination test (GAT) was performed with a panel of control donors with known HNA1-5 antigens, using the maternal serum as a reagent. We did also a Luminex screening assay for detection of anti-HLA and anti-HNA antibodies in the mother serum. The HLA and HNA genotypes were identified, which allowed to define specificities in mother's antibodies against the neutrophil surface antigens from her husband and from the twins. The diagnosis of NAN diagnose is not done in most hospitals worldwide, mainly by the difficulty in executing the histocompatibility test. However, the crossmatch by flow cytometry could be easily done in clinical laboratories following the method described in this article.

Diagnosis and treatment of immunological platelet refractoriness by histocompatibility.

Immunological platelet refractoriness occurs when polytransfused patients develop antibodies against donors' HLA class I antigens, HPA (human platelet antigens) and few cases against both systems. Flow cytometry crossmatch with the patient serum against platelets from several donors can determine whether the refractoriness is or is not of immunological origin. Patients with moderate sensitization will be given transfusions from donors with a negative platelets crossmatch; those who are hypersensitized will need to have antibodies assessed against a reactivity panel (RP) for HLA class I and HPA. The patient must be typed for HLA and HPA in order to identify best donors. We have compiled a list of 500 donors registered at our blood bank with known HLA and HPA profiles. Pre-transfusion crossmatch is performed against donors selected virtually, transfusing those who are negative. We analyzed 75 patients with refractoriness, 67% (50/75) of whom had anti-HLA or anti-HPA antibodies and 56% (28/50) were hypersensitized, with RP ≥ 80%. The diagnosis of the immunological refractoriness and the compatibility between donor and recipient allowed efficient transfusions for all patients.

Síndromes MonoMAC e Emberger em paciente com mutação no gene GATA2 / MonoMAC and Emberger syndromes in a patient with GATA2 mutation

As mutações que ocorrem no gene GATA2 podem ocasionar um amplo espectro de doenças genéticas. Os pacientes podem ter anormalidades na hematopoiese, na linfangiogenesis e na resposta imunológica. Os fenótipos incluem algumas síndromes caracterizadas por monocitopenia e infecção por micobactéria (síndrome MonoMac), síndrome mielodisplásica familiar, leucemia mieloide crônica ou aguda, síndrome de Emberger (linfedema primário), e mais raramente neutropenia, anemia aplástica e deficiência isolada de células NK. A idade da apresentação clínica pode variar desde a infância até a idade adulta. A deficiência autossômica dominante de GATA2 pode permanecer clinicamente silenciosa por décadas, ou mesmo durante toda a vida. Descrevemos o caso de uma jovem brasileira que apresentou a maioria dos problemas ligados à mutação no gene GATA2, observando-se as duas síndromes: MonoMAC e Emberger.

GATA2 mutations may cause a wide spectrum of genetic disorders. Patients may have several abnormalities in hematopoiesis, lymphangiogenesis and immune response. The phenotypes include monocytopenia and mycobacterial infection (MonoMAC) syndrome, familial myelodysplastic syndrome (MDS), chronic or acute myeloid leukemia (CML or AML), Emberger syndrome and, more rarely, neutropenia, aplastic anemia and isolated NKcell deficiency. Age at clinical onset ranges from early childhood to late adulthood. Autosomal dominant GATA2 deficiency may remain clinically silent for decades or even for life. We report a case of a Brazilian young patient who had most of the problems related to GATA2 mutation as well as MonoMAC and Emberger syndromes.

Accuracy of the median channel shift in the flow cytometry for predicting complement dependent cytotoxicity crossmatching in kidney transplant candidates.

Crossmatching either by complement-dependent cytotoxicity (CDC) and/or by flow cytometry (FCXM) are routinely used for assessing anti-HLA donor antibodies before kidney transplantation. FCXM has demonstrated greater sensitivity and many transplant centers have opted for its use without the concomitant CDC assay. The objective of this study was to evaluate the accuracy of the median channel shift (MCS) in the FCXM in predicting the CDC assay results. A total of 1516 T cell FCXM and 1408 B cell FCXM were studied in deceased donors lymphocytes between January/2016 and March/2017. The high detection rate of CDC+ results by FCXM+ resulted in 87% (FCXM-T) and 90% (FCXM-B) sensitivity, and 98% negative predictive value, for both. The low specificity of FCXM B (43%) is atributed to cases of CDC-/FCXMB+. FCXM T and B were able to detect 53% and 76% of cases with donor specific antibodies of classes I and II with intensity of fluorescence ≥5001. The MCS differentiated CDC+ (Md, P25 and P75) results: MCS-T 390 (245-469) and MCS-B 282 (180-350). Through ROC curve analysis (AUC), the MCS showed satisfactory performance in detecting CDC+: MCS-T 0.909 (0.886-0.933) and MCS-B 0.775 (0.724-0.826). Considering the accuracy and sensitivity evaluation, the MCS-T 245 and MCS-B 282 cutoffs showed a better prediction of CDC+. This study showed that it is possible to calibrate MCS based on CDC+ with accuracy >90%, however, that leads to a risk in terms of non-detection of low-titer anti-HLA antibodies.

Comparative analysis of two methods to detect donor-specific anti-HLA antibodies after kidney transplant.

Preformed anti-human leukocyte antigen (HLA) antibodies may be present in the blood of kidney transplant candidates. The production of these antibodies may occur in the post-transplant period, with the possible development of donor-specific antibodies (DSA). Luminex-based tests, such as the single antigen (SA) assay and the Luminex crossmatch (Xm-DSA) assay are the most commonly used tools to detect anti-HLA antibodies, due to their high sensitivity and specificity. This cross-sectional study aimed to compare the findings of two methods for the detection of DSAs after kidney transplant: SA and Xm-DSA. A total of 122 patients who underwent deceased donor kidney transplant at Hospital de Clínicas de Porto Alegre were included. The SA assay detected anti-class I HLA DSAs in 17 patients (13.9%) and anti-class II HLA DSAs in 22 patients (19.6%), whereas the Xm-DSA detected DSAs in 18 patients (14.8%) both against class I and class II antigens. There was agreement between the two methods for class I (kappa = 0.66, p = 0.001) and class II (kappa = 0.54, p = 0.025) antigens. The incidence of DSAs as obtained by the SA assay was 15.57%, and the most prevalent DSAs were those against HLA-DR antigens. Patient survival at 3 years was 92%. The two techniques assessed in this study provide important information on the presence of DSAs and may help in the post-transplant patient monitoring and in immunosuppressive strategy.

Blood chimerism in twins.

CONCLUSIONS: Chimerism is a phenomenon in which an individual has cells with different genetic content from different zygotes. In dizygotic twins (DTs), chimerism is believed to occur through placental anastomoses that enable the bidirectional exchange of hematopoietic stem cells. Little is still known about chimerism frequency in twins, but several studies have shown a relation between chimerism and some conditions such as autism, Alzheimer's disease, and a group of autoimmune diseases such as Sjögren syndrome, systemic lupus erythematosus, and systemic sclerosis. In addition to chimerism of ABO blood groups being possibly mistaken for ABO subgroups, these autoimmune diseases may affect other serologic immunohematologic tests. This study aimed to determine the frequency of chimerism in DTs through ABO and D testing using the tube method, column agglutination, and short tandem repeat (STR) assays. Among the 103 subjects assessed for this study, 24 subjects (12 pairs) were excluded because STR assays showed they were monozygotic; of the remaining, 70 subjects (35 pairs) were DTs and 9 subjects came from gestations of trizygotic triplets. No ABO or D chimerism was detected in any subject through serologic assays, and STR assays did not detect any blood chimerism. Although there was no evidence of chimerism found in this study, we emphasize the importance of observing the family background of individuals with suspected ABO subgroup in complex immunohematologic studies because ABO antigen-antibody reactions are similar in both circumstances, and chimerism can be overlooked. Moreover, the use of the STR analysis method in chimerism studies can be important to help differentiate chimerism and ABO subgroups.

CXCR2 +1208 CT genotype may predict earlier clinical stage at diagnosis in patients with prostate cancer.

Interleukin-8 (IL-8) is an angiogenic CXC chemokine that plays an important role in both the development and progression of several human malignancies including prostate cancer (PC). A single nucleotide polymorphism (SNP) at -251 upstream of the transcriptional start site of the IL-8 gene has been shown to influence its production. The effects of IL-8 are mediated by two highly related chemokine receptors, CXCR1 and CXCR2. The present study investigated the influence of the IL-8 and CXCR2 gene variation on susceptibility and clinicopathological characteristics of PC in a group of Brazilian subjects. METHODS: Two hundred and one patients and 185 healthy controls were enrolled in a case-control study. Blood was collected for DNA extraction; typing of IL-8 -251 T/A and CXCR2 +1208 C/T genes was performed by polymerase chain reaction with sequence-specific primers (PCR-SSP), followed by agarose gel electrophoresis. Risk association between the genotypes, PC susceptibility and tumor characteristics was estimated by odds ratio (OR) and 95% confidence intervals (95% CI) using logistic regression analysis, after adjusting for age at diagnosis. RESULTS: A significant association was found between the heterozygous CXCR2 +1208 CT genotype and stage of PC. The CXCR2 +1208 CT genotype was significantly less frequent in patients with clinical stage T3-T4 compared to T1-T2 (56.7 versus 80.5%). Our findings suggest that carriers of the CXCR2 +1208 CT genotype had a protective effect for advanced PC (CT versus CC: adjusted OR=0.25; P=0.02). No association was observed between the SNP for IL-8 -251 T/A and clinicopathological parameters of PC. CONCLUSION: These results indicated that the CXCR2 +1208 CT genotype is less frequent in advanced stages of PC, suggesting that this chemokine receptor plays a role in the pathogenesis of this disease.

Reduced frequency of two activating KIR genes in patients with sepsis.

Natural killer (NK) cell activity is regulated by activating and inhibitory signals transduced by killer cell immunoglobulin-like receptors (KIR). Diversity in KIR gene repertoire among individuals may affect disease outcome. Sepsis development and severity may be influenced by genetic factors affecting the immune response. Here, we examined sixteen KIR genes and their human leucocyte antigen (HLA) class I ligands in critical patients, aiming to identify patterns that could be associated with sepsis. Male and female patients (ages ranging between 14 and 94years-old) were included. DNA samples from 211 patients with sepsis and 60 controls (critical care patients with no sepsis) collected between 2004 and 2010 were included and genotyped for KIR genes using the polymerase chain reaction method with sequence-specific oligonucleotide (PCR-SSO), and for HLA genes using the polymerase chain reaction method with sequence-specific primers (PCR-SSP). The frequencies of activating KIR2DS1 and KIR3DS1 in sepsis patients when compared to controls were 41.23% versus 55.00% and 36.49% versus 51.67% (p=0.077 and 0.037 respectively before Bonferroni correction). These results indicate that activating KIR genes 2DS1 and 3DS1 may more prevalent in critical patients without sepsis than in patients with sepsis, suggesting a potential protective role of activating KIR genes in sepsis.

KIR genes and HLA class I ligands in a Caucasian Brazilian population with colorectal cancer.

Colorectal cancer (CRC) can occur anywhere in the colon or rectum and represents the third most common cancer in the world in both sexes. Natural killer cells (NK) are part of the innate immune system recognizing class I HLA molecules on target cells through their membrane receptors, called killer cell immunoglobulin-like receptors (KIR). The aim of our study was to evaluate the association between the KIR genes and HLA ligands in patients with colorectal cancer and healthy controls. We examined the polymorphism of 16 KIR genes and their HLA ligands in 154 caucasoid CRC patients and 216 controls. When both groups were compared, no significant differences were found for HLA ligands and KIR genes after Bonferroni correction. However, the Bx haplotypes (heterozygous and homozygous for the haplotype B) were more frequent in controls, when compared with patients. These findings suggest that individuals with Bx haplotypes could have some protection to colorectal cancer. The hypothesis is not related with the presence of a special KIR gene and HLA ligand related to the disease, but to the presence of several activating genes in the individuals with no better action of one in relation to other. Further studies to confirm this observation are warranted.

Association between KIR genotypes and HLA-B alleles on viral load in Southern Brazilian individuals infected by HIV-1 subtypes B and C.

There is a great variety of HIV-1 subtypes circulating in Brazil, including subtype C, whose prevalence is on the rise, particularly in the southern region. Many host and viral genetic factors may be involved in this trend. We evaluated the influence of human leukocyte antigen (HLA) class I alleles and killer-cell immunoglobulin-like receptor (KIR) genotypes on viral set point and T-CD4(+) parameters in 84 treatment-naïve HIV-1-positive individuals. Frequency data in the infected group were compared to data of 548 healthy control subjects. Individuals with the KIR AA genotype had a higher viral load (VL) than individuals with the KIR Bx genotype. The HIV-1 group was subdivided into three subgroups according to HLA-B allele presence: those with protection to disease alleles (HLA-B(+)), accelerated disease progression alleles (HLA-B(-)), or neither (HLA-B(o)) were grouped. We observed a significant effect of the HLA-B allele presence on VL. The HLA-B(+) group had significantly lower VL than the HLA-B(-) group and trended toward a lower VL than the HLA-B(o) group. There were significant differences between groups expressing extreme VL values: KIR-AA+HLA-B(-) vs. KIR Bx+HLA-B(+) and KIR-AA+HLA-B(o)vs. KIR Bx+HLA-B(+). The relationship of KIR/HLA host genetics with slow HIV disease progression in southern Brazil may be useful for vaccine developers, epidemiologists, and clinicians.

Quantification of mixed chimerism allows early therapeutic interventions.

Hematopoietic stem cell transplantation is the curative option for patients with myelodysplastic syndrome; however, it requires a long post-transplantation follow-up. A 53-year-old woman with a diagnosis of myelodysplastic syndrome underwent related donor allogeneic hematopoietic stem cell transplantation in July 2006. Three months after transplantation, a comparative short tandem repeat analysis between donor and recipient revealed full chimerism, indicating complete, healthy bone marrow reconstitution. Three years and ten months after hematopoietic stem cell transplantation, the patient developed leukopenia and thrombocytopenia. Another short tandem repeat analysis was carried out which showed mixed chimerism (52.62%), indicating relapsed disease. A donor lymphocyte infusion was administered. The purpose of donor lymphocyte infusion is to induce a graft-versus-leukemia effect; in fact, this donor's lymphocyte infusion induced full chimerism. Successive short tandem repeat analyses were performed as part of post-transplantation follow-up, and in July 2010, one such analysis again showed mixed chimerism (64.25%). Based on this finding, a second donor lymphocyte infusion was administered, but failed to eradicate the disease. In September 2011, the patient presented with relapsed disease, and a second related donor allogeneic hematopoietic stem cell transplantation was performed. Subsequent short tandem repeat analyses revealed full chimerism, indicating complete bone marrow reconstitution. We conclude that quantitative detection of mixed chimerism is an important diagnostic tool that can guide early therapeutic intervention.

Expression patterns of B cells in acute kidney transplant rejection.

OBJECTIVES: To evaluate B-cell expression patterns and association with function and survival in dysfunctional kidney allografts. MATERIALS AND METHODS: There were 110 kidney transplant recipients included who had for-cause biopsies. Demographic and transplant data were collected. Immunostaining for B cells, plasma cells, and C4d was performed by the immunoperoxidase technique in paraffin-embedded samples. Circulating antihuman leukocyte antigen donor-specific antibodies were detected in a single-antigen assay at biopsy. The main outcomes were kidney graft survival and function. The patients were evaluated in 3 groups according to the Banff classification: no rejection (40 patients), T-cell-mediated rejection (50 patients), and antibody-mediated rejection (20 patients). RESULTS: The CD138-positive plasma cell-rich infiltrates predominated in antibody-mediated rejection and were associated with stronger reactivity against panel antibodies (r = 0.41; P ≤ .001) and positive donor-specific antibodies (r = 0.32; P ≤ .006). The CD20-positive lymphocytes were associated with T-cell-mediated rejection, increased human leukocyte antigen mismatch, and frequency of retransplant. The CD138-positive cell infiltrates also were significantly greater in patients who had late than early rejection. There was no correlation between cellular CD20 and CD138 expression, and neither CD20 nor CD138 predicted worse graft function or survival. Other markers of antibody-mediated rejection such as C4d and donor-specific antibodies were associated with worse graft function and survival at 4 years after transplant. In multivariate analysis, C4d was the only risk factor associated with graft loss. CONCLUSIONS: After kidney transplant, CD20-positive B-cell infiltrates were associated with T-cell-mediated rejection, and CD138-positive plasma cells were associated with antibody-mediated rejection. Graft loss was associated with the presence of C4d.

Quantification of mixed chimerism allows early therapeutic interventions

Hematopoietic stem cell transplantation is the curative option for patients with myelodysplastic syndrome; however, it requires a long post-transplantation follow-up. A 53-year-old woman with a diagnosis of myelodysplastic syndrome underwent related donor allogeneic hematopoietic stem cell transplantation in July 2006. Three months after transplantation, a comparative short tandem repeat analysis between donor and recipient revealed full chimerism, indicating complete, healthy bone marrow reconstitution. Three years and ten months after hematopoietic stem cell transplantation, the patient developed leukopenia and thrombocytopenia. Another short tandem repeat analysis was carried out which showed mixed chimerism (52.62%), indicating relapsed disease. A donor lymphocyte infusion was administered. The purpose of donor lymphocyte infusion is to induce a graft-versus-leukemia effect; in fact, this donor's lymphocyte infusion induced full chimerism. Successive short tandem repeat analyses were performed as part of post-transplantation follow-up, and in July 2010, one such analysis again showed mixed chimerism (64.25%). Based on this finding, a second donor lymphocyte infusion was administered, but failed to eradicate the disease. In September 2011, the patient presented with relapsed disease, and a second related donor allogeneic hematopoietic stem cell transplantation was performed. Subsequent short tandem repeat analyses revealed full chimerism, indicating complete bone marrow reconstitution. We conclude that quantitative detection of mixed chimerism is an important diagnostic tool that can guide early therapeutic intervention...

Analysis of KIR gene frequencies and HLA class I genotypes in breast cancer and control group.

Breast cancer is the main cause of cancer-related death among women, with a 0.5% increase in incidence per year. Natural killer cells (NK) are part of the innate immune system recognizing class I HLA molecules on target cells through their membrane receptors, called killer cell immunoglobulin-like receptors (KIR). The aim of our study was to evaluate the association between the KIR genes and HLA alleles in patients with breast cancer and healthy controls. Two hundred thirty patients with breast cancer and 272 healthy controls were typed for HLA class I and KIR genes by PCR-SSO. When both groups were compared, the presence of inhibitory KIR2DL2 receptors was significantly higher in breast cancer patients than in healthy controls. No significant differences were found for HLA-C2 and HLA-Bw4. However, a higher frequency of HLA-C1 in breast cancer patients was observed. These findings suggest a potential role for the KIR gene system in breast cancer. Further studies to confirm this observation are warranted.

Characteristics of NK cell activity in patients with systemic sclerosis.

INTRODUCTION: Previous studies have shown an increased expression of natural killer (NK) cells in the peripheral blood of patients with systemic sclerosis (SSc). NK cells are part of innate immunity, recognizing infected cells through killer immunoglobulin-like receptors (KIR), which show marked polymorphism. A novel model has been proposed predicting the activity of NK cells, evaluating whether there is excessive activation (EA), excessive inhibition (EI) or balance (B) (neutral). OBJECTIVE: To evaluate the activity of NK cells in patients with SSc and compare it with that of a control group. METHOD: This study comprised 110 patients with SSc and 115 healthy controls. A novel model that predicts the activity of NK cells was used. For that, cells with their respective KIR/HLA-C and Bw4 ligands were considered. The activity of NK cells was defined as EA, EI, or B. RESULTS: Our results showed that 63.5% of healthy controls had the KIR phenotype characterized by EI, as compared with 39.1% of the patients with SSc (P = 0.001). Considering only KIR2DL2-positive individuals, 34.7% of EI was found in healthy controls and 10.9% in patients with SSc (P < 0.001). CONCLUSION: In our study, the model that predicts the action of NK cells showed that healthy controls have higher frequency of EI as compared with SSc patients, suggesting a protective effect of the EI profile against the development of SSc. These results suggest a potential role of NK cells in the pathogenesis of SSc, but further studies should be conducted to confirm our data.

Características de atividade das células natural killer em pacientes com esclerose sistêmica / Characteristics of NK cell activity in patients with systemic sclerosis

INTRODUÇÃO: Estudos têm relatado um aumento da expressão das células natural killer (NK) no sangue periférico de pacientes com esclerose sistêmica (ES). Essas células fazem parte da imunidade inata, reconhecendo células infectadas por meio dos receptores killer immunoglobulin-like receptor (KIR), que apresentam acentuado polimorfismo. Um novo modelo foi proposto prevendo a atividade das células NK, avaliando o excesso de ativação (EA), excesso de inibição (EI) ou se a célula está funcionalmente em equilíbrio (balance, B) (neutra). OBJETIVO: Avaliar a atividade das células NK em pacientes com ES e comparar com grupo-controle. MÉTODO: Cento e dez pacientes com ES e 115 controles foram estudados. Foi aplicado um novo modelo que prevê a atividade das células NK. Para esse método, considerou-se cada célula com seu respectivo ligante KIR/HLA-C e Bw4. A nomenclatura utilizada foi EA, EI e B. RESULTADOS: Nossos resultados mostraram que 63,5% dos controles saudáveis apresentavam o fenótipo KIR caracterizado por EI, em comparação com 39,1% dos pacientes com ES (P = 0,001). Considerando-se somente indivíduos com presença de KIR2DL2 (KIR2DL2+), encontramos 34,7% de EI em controles sadios e 10,9% em pacientes com ES (P < 0,001). CONCLUSÃO: Em nosso estudo, o modelo que prevê a ação das células NK mostrou que controles sadios têm maior frequência de EI quando comparados a pacientes com ES, sugerindo um efeito protetor do EI contra o desenvolvimento da ES. Outros estudos, porém, devem ser realizados para confirmar nossos dados.

INTRODUCTION: Previous studies have shown an increased expression of natural killer (NK) cells in the peripheral blood of patients with systemic sclerosis (SSc). NK cells are part of innate immunity, recognizing infected cells through killer immunoglobulin-like receptors (KIR), which show marked polymorphism. A novel model has been proposed predicting the activity of NK cells, evaluating whether there is excessive activation (EA), excessive inhibition (EI) or balance (B) (neutral). OBJECTIVE: To evaluate the activity of NK cells in patients with SSc and compare it with that of a control group. METHOD: This study comprised 110 patients with SSc and 115 healthy controls. A novel model that predicts the activity of NK cells was used. For that, cells with their respective KIR/HLA-C and Bw4 ligands were considered. The activity of NK cells was defined as EA, EI, or B. RESULTS: Our results showed that 63.5% of healthy controls had the KIR phenotype characterized by EI, as compared with 39.1% of the patients with SSc (P = 0.001). Considering only KIR2DL2-positive individuals, 34.7% of EI was found in healthy controls and 10.9% in patients with SSc (P < 0.001). CONCLUSION: In our study, the model that predicts the action of NK cells showed that healthy controls have higher frequency of EI as compared with SSc patients, suggesting a protective effect of the EI profile against the development of SSc. These results suggest a potential role of NK cells in the pathogenesis of SSc, but further studies should be conducted to confirm our data.