Flow cytometric analysis of TCR Vß repertoire in patients with 22q11.2 deletion syndrome.

In 22q11.2 deletion patients, the normal decrease in T lymphocyte counts after 1-2 years is blunted such that relatively T lymphocyte numbers increase over early childhood, probably via post-thymic expansion of peripheral lymphocytes. This may leave less T lymphocyte receptor (TCR) diversity than when derived from naive thymic emigrants. We analysed TCR Vß repertoire on 27 22q11.2 chromosome deletion patients. No patient had infection at sampling. CD3(+) CD4(+) recent thymic emigrants (RTEs) were identified by CD45RA and CD31 expression. TCR Vß repertoire was determined using four-colour flow cytometry. Patients and controls showed significant TCR Vß family usage differences between CD3(+) CD4(+) and CD3(+) CD4(-) T lymphocyte subpopulations. Vß family abnormalities (±3 SD of controls) were identified in 18/27 (67%) patients and 12/47 (25%) controls. In patients, the magnitude of expansions was increased, with some Vß families representing 37% of the cells present in the subpopulations. There was a significant increase in frequency of abnormalities in CD3(+) CD4(+) (P < 0.001) and CD3(+) CD4(-) T lymphocytes (P < 0.05) in patients. A total of 11/16 patients had an abnormal CD4(+) CD25(Bright) TCR Vß repertoire. There was no difference in expansions/contractions between CD4(+) CD25(Bright) and CD4(+) T lymphocyte repertoires (P = 0.575) for individual patients but significant differences in expansions/contractions between CD4(+) CD25(Bright) and CD8(+) T lymphocytes repertoires (P = 0.011). There was bias in Vß usage between CD3(+) CD4(+) and CD3(+) CD4(-) T lymphocyte subsets. A total of 67% patients had TCR Vß repertoire abnormalities, with a trend towards increased repertoire abnormalities with fewer RTEs, suggesting thymic output plays an important role in TCR repertoire diversity. There was no correlation between skewed repertoire and symptoms of infection or autoimmunity.

MRC OX-22, a monoclonal antibody that labels a new subset of T lymphocytes and reacts with the high molecular weight form of the leukocyte-common antigen.

A mouse monoclonal antibody (MRC OX-22) is described that labels rat T cells which mediate graft-versus-host reactions and those responsible for the suppression of antibody synthesis in hosts undergoing these reactions. In contrast, most of the T cells that provide help for B cells are MRC OX-22 negative. These results, taken together with those published previously, demonstrate that the rat contains at least three phenotypically and functionally distinct subsets of T cells. The MRC OX-22 antibody also labels all B cells, 50% of bone marrow cells, but only 2% of thymocytes. Of these latter cells about half are found at the edge of the medulla and the remainder are randomly distributed throughout the cortex and medulla. These findings lend support to the view that mature thymocytes leave the thymus at the cortico-medullary junction, and also suggest that both cortex and medulla may be sites where thymocytes mature. Biochemical studies showed that the MRC OX-22 antibody reacts with the high molecular weight form of the leukocyte-common antigen (L-CA). Comparison with data on human L-CA suggests that the molecular and antigenic heterogeneity of this set of glycoproteins has been conserved between rat and man.

Pattern recognition receptor expression is not impaired in patients with chronic mucocutanous candidiasis with or without autoimmune polyendocrinopathy candidiasis ectodermal dystrophy.

Patients with chronic mucocutaneous candidiasis (CMC) have an unknown primary immune defect and are unable to clear infections with the yeast Candida. CMC includes patients with AIRE gene mutations who have autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), and patients without known mutations. CMC patients have dysregulated cytokine production, suggesting that defective expression of pattern recognition receptors (PRRs) may underlie disease pathogenesis. In 29 patients with CMC (13 with APECED) and controls, we assessed dendritic cell (DC) subsets and monocyte Toll-like receptor (TLR) expression in blood. We generated and stimulated monocyte-derived (mo)DCs with Candida albicans, TLR-2/6 ligand and lipopolysaccharide and assessed PRR mRNA expression by polymerase chain reaction [TLR-1-10, Dectin-1 and -2, spleen tyrosine kinase (Syk) and caspase recruitment domain (CARD) 9] in immature and mature moDCs. We demonstrate for the first time that CMC patients, with or without APECED, have normal blood levels of plasmocytoid and myeloid DCs and monocyte TLR-2/TLR-6 expression. We showed that in immature moDCs, expression levels of all PRRs involved in anti-Candida responses (TLR-1, -2, -4, -6, Dectin-1, Syk, CARD9) were comparable to controls, implying that defects in PRR expression are not responsible for the increased susceptibility to Candida infections seen in CMC patients. However, as opposed to healthy controls, both groups of CMC patients failed to down-regulate PRR mRNA expression in response to Candida, consistent with defective DC maturation, as we reported recently. Thus, impaired DC maturation and consequent altered regulation of PRR signalling pathways rather than defects in PRR expression may be responsible for inadequate Candida handling in CMC patients.

T cell receptor Vbeta repertoire of T lymphocytes and T regulatory cells by flow cytometric analysis in healthy children.

Evaluation of the T cell receptor (TCR) Vbeta repertoire by flow cytometric analysis has been used for studying the T cell compartments for diseases in which T cells are implicated in the pathogenesis. For the interpretation of these studies information is needed about Vbeta usage in healthy individuals and there are few data for normal usage in paediatric populations. We examined the T lymphocyte (sub)populations in 47 healthy controls (age range: 3 months-16 years). We found non-random Vbeta usage with skewed reactivity of some families towards CD4+ or CD4- T cells. Importantly, there appeared to be no significant change in Vbeta usage according to age group. Some controls showed expansions in some Vbeta families, although incidence of such expansions was low. We went on to examine the repertoire of CD4+CD25(Bright) T regulatory cells in 25 healthy controls. We found overlapping quantitative usage for each of the Vbeta families between CD4+CD25- and CD4+CD25(Bright) T cells. However, there was a significant preferential usage for five Vbeta families and decreased usage of two Vbeta families in the CD4+CD25(Bright) T cells, suggesting that although they overlap there may be subtle but important differences in the TCR repertoire of T regulatory cells.

Impaired dendritic cell maturation and cytokine production in patients with chronic mucocutanous candidiasis with or without APECED.

Patients with chronic mucocutaneous candidiasis (CMC) suffer persistent infections with the yeast Candida. CMC includes patients with autoimmune regulator (AIRE) gene mutations who have autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), and patients without known mutations. CMC patients have dysregulated cytokine production, and dendritic cells (DCs), as central orchestrators, may underlie pathogenic disease mechanisms. In 29 patients with CMC (13 with APECED) and controls, we generated monocyte-derived DCs, stimulated them with Candida albicans, Toll-like receptor-2/6 ligand and lipopolysaccharide to assess cytokine production [interleukin (IL)-12p70, IL-23, interferon (IFN)-gamma, IL-2, tumour necrosis factor (TNF)-alpha, IL-6, transforming growth factor-beta, IL-10, IL-5, IL-13] and cell-surface maturation marker expression (CD83, CD86, human leucocyte antigen D-related). In both APECED and non-APECED CMC patients, we demonstrate impairment of DC function as evidenced by altered cytokine expression profiles and DC maturation/activation: (1) both groups over-produce IL-2, IFN-gamma, TNF-alpha and IL-13 and demonstrate impaired DC maturation. (2) Only non-APECED patients showed markedly decreased Candida-stimulated production of IL-23 and markedly increased production of IL-6, suggesting impairment of the IL-6/IL-23/T helper type 17 axis. (3) In contrast, only APECED patients showed DC hyperactivation, which may underlie altered T cell responsiveness, autoimmunity and impaired response to Candida. We demonstrate different pathogenic mechanisms on the same immune response pathway underlying increased susceptibility to Candida infection in these patients.

Best practice in primary care pathology: review 6.

This sixth best practice review examines four series of common primary care questions in laboratory medicine: (1) laboratory monitoring in hypertension and heart failure abnormalities; (2) markers of inflammatory joint disease; (3) laboratory investigation of chronic diarrhoea; and (4) mumps and chickenpox. The review is presented in question-answer format, referenced for each question series. The recommendations represent a precis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by Medline Embase searches to identify relevant primary research documents. They are not standards but form a guide to be set in the clinical context. Most are consensus based rather than evidence based. They will be updated periodically to take account of new information.

Best practice in primary care pathology: review 2.

This second best practice review examines five series of common primary care questions in laboratory medicine: (1) laboratory testing for allergy, (2) diagnosis and monitoring of menopause, (3) the use of urine cytology, (4) the usefulness of the erythrocyte sedimentation rate, and (5) the investigation of possible urinary tract infection. The review is presented in a question-answer format. The recommendations represent a précis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents, and evidence based medicine reviews, supplemented by MEDLINE EMBASE searches to identify relevant primary research documents. They are standards but form a guide to be set in the clinical context. Most are consensus rather than evidence based. They will be updated periodically to take account of new information.

Psychology, immunology, and HIV.

The interdisciplinary field of psychoneuroimmunology (PNI), which aims to clarify the relationship between psychological factors and immunity, can also play a role in our understanding of individual susceptibility to, progression of immunologically mediated disease. Mechanisms proposed to account for the profoundly damaging effects of human immunodeficiency virus (HIV) on immune function do only partially explain the variability in individual rates of progression, suggesting, therefore, that other immunomodulatory factors are also involved. Studies have examined the proposal that the effects of stress and HIV may interact in some complex way, and psychological, physiological and virological evidence for the role of stress in HIV progression is discussed in detail. A critical review of HIV-specific research in PNI, which can be broadly divided into cross-sectional, longitudinal, and intervention studies, and studies of long-term survivors, reveals that the relationship between stress and HIV progression remains equivocal, because of limitations due to methodological difficulties and to our inadequate understanding of immunology and HIV. A model is proposed for the influence of psychosocial stress on progression in HIV disease, which takes account of some of these difficulties.

Paraneoplastic pemphigus occuring after radiotherapy for relapsed non-Hodgkin's lymphoma in a patient with common variable immunodeficiency.

Paraneoplastic pemphigus (PNP) is a rare multisystem, autoimmune disease with prominent mucocutaneous manifestations, occurring most commonly in association with haematological malignancies. It is characterised by the presence of circulating autoantibodies against epithelial adhesion proteins. We report a 46-year-old woman with common variable immunodeficiency who developed paraneoplastic pemphigus after receiving radiotherapy for relapsed non-Hodgkin's lymphoma. Flaccid bullae covering approximately 70% of the skin, painful oropharyngeal ulceration and periocular erosions were prominent clinical features. Despite supportive treatment and attempts at disease control using high-dose corticosteroids and cyclophosphamide, the patient became increasingly debilitated, developed septic shock secondary to Pseudomonas aeruginosa septicaemia on two occasions and died of respiratory failure 6 weeks after presentation. We highlight the need to be aware of (PNP) and to perform appropriate immunological investigations. In addition, we emphasise the importance of a multidisciplinary approach to the management of such patients.

Polysaccharide antibody responses are impaired post bone marrow transplantation for severe combined immunodeficiency, but not other primary immunodeficiencies.

Established treatment of severe combined immunodeficiencies (SCID) and other primary immunodeficiencies (PID) is bone marrow transplantation (BMT). Normal lymphocyte numbers and protein antigen responses are present within 2 years of BMT, polysaccharide antibody responses appear last. Streptococcus pneumoniae infection causes significant morbidity and mortality post-BMT. Previous studies have shown good protein antigen responses post-BMT for SCID and PID, but had not examined the polysaccharide responses. We retrospectively analysed pneumococcal polysaccharide (PPS) responses in our patient series. In total, 22 SCID and 12 non-SCID PID were evaluated, all >2 years post BMT: 17 SCID, 12 PID received chemotherapy conditioning; 17 SCID, three PID had T-cell depleted (TCD) BMT, others had nonconditioned whole marrow BMT. All had normal Haemophilus influenza B and tetanus antibody responses. Of 22 SCID, 13 vs 11/12 PID responded to PPS vaccine (P=0.05). There was no association with donor age, GvHD, B-cell chimerism, or IgG2 level. Fewer TCD marrow recipients responded to PPS (P=0.04). Analysis of the SCID group showed no association of PPS response with type of marrow received. This is the first study to specifically examine PPS antibody responses following SCID and PID BMT. Pneumococcal conjugate vaccine antibody responses should be examined in these children.

Formalin fixation and patterns of antineutrophil cytoplasmic antibodies.

Recent publications have suggested that fixing neutrophils in formalin is a useful adjunct to the differentiation of antinuclear antibodies from perinuclear antineutrophil cytoplasmic antibodies. In this small comparative study of 30 sera the use of an additional slide of formalin fixed neutrophils did not add any useful information and may be confusing as the results were not reproducible.

Survey of infection in patients receiving antibody replacement treatment for immune deficiency.

BACKGROUND: Primary antibody deficiency disorders are a heterogeneous group of disorders, which are treated by regular infusions of immunoglobulin. Despite replacement treatment, patients remain susceptible to infection. Effective management of infections is necessary to prevent the complications of chronic infection. AIMS: This retrospective survey of clinical practice examined the management of infections in patients who receive immunoglobulin replacement for immune deficiency. METHODS: Patients who received immunoglobulin replacement treatment in Newcastle during the year 2000 were identified. Medical records were reviewed. Basic clinical information and details of immunoglobulin replacement treatment were recorded. Episodes of infection were defined by documented symptoms, signs, or investigation results, and by the prescription of an antibiotic course. Details of episodes of infection and antimicrobial treatment were recorded. RESULTS: Thirty seven patients received immunoglobulin replacement during 2000. There were 101 episodes of infection. There was no correlation between the frequency of infection and the IgG trough value. Respiratory tract infections were most common (71 of 101). Where documented, 80% of infections were associated with clinical signs, 21% with pyrexia, and 64% with a raised C reactive protein value. Microbiological culture was performed in 30% of infections. Antimicrobial treatment was instituted along "best guess" lines in 99 of 101 episodes of infection. CONCLUSIONS: Management of respiratory tract infections represents the largest problem in antibody deficient patients. Greater use of microbiological culture might allow more effective prescription of antimicrobial treatment. The generation of treatment guidelines and improved communication with general practitioners could improve the management of all episodes of infection.

Scedosporium apiospermum in chronic granulomatous disease treated with an HLA matched bone marrow transplant.

A patient with chronic granulomatous disease who was being treated with steroids was diagnosed with a soft tissue Scedosporium apiospermum infection. Despite extensive treatment with antifungals progression to involve solid tissue (bone) occurred. Treatment required an HLA matched bone marrow transplant, which led to complete clearance of the fungal infection, although the patient subsequently died.

Granulomatous disease in common variable immunodeficiency: effect on immunoglobulin replacement therapy and response to steroids and splenectomy.

A 40 year old white woman with common variable immunodeficiency of four years duration presented with rapidly increasing splenomegaly. Despite high dose, weekly intravenous immunoglobulin, it was impossible to raise the trough serum IgG concentration to within the normal range. While waiting for a diagnostic splenectomy, low dose corticosteroids were started, leading to a decrease in the size of the spleen and an increase in the trough IgG concentration. Both spleen and liver showed non-caseating granulomas. Following splenectomy, the corticosteroids were tailed off and the trough IgG was maintained well into the normal range on a reduced, fortnightly dose of intravenous immunoglobulin and a low dose of oral corticosteroid.

Northern region asplenia register--analysis of first two years.

OBJECTIVES: To assess the feasibility of setting up a register of patients with asplenia within a defined geographical area; to ensure that guidelines on best practice were implemented; to obtain information on antibody levels to pneumococcal capsular polysaccharides and Haemophilus influenzae type b capsular polysaccharide, before and after immunisation and annually thereafter; to raise awareness of risks among clinicians and to offer advice on management. DESIGN: Prospective recruitment using multiple sources of recruitment. Annual follow up reminders sent from Registration Centre. SUBJECTS: Population of (old, pre-1995) Northern Health Region: approximately 3.1 million. MAIN OUTCOME MEASURES: Data were obtained on reasons for asplenia, duration of asplenia, use of prophylactic antibiotics, Medic-Alert bracelets, immunisations, antibody levels, death. RESULTS: The register was initiated at the beginning of April 1995 and ran to the end of March 1997. After two years of operation, 1111 cases had been registered but the response from some health districts was poor. Major primary causes of asplenia were trauma (264), other surgical (198), lymphoproliferative disease (154), and idiopathic thrombocytopenic purpura (147). There were 664 patients on prophylactic antibiotics, of whom 498 were on continuous antibiotics. Only 18 had any type of warning bracelet. Antibody measurements were carried out at least once on 75% of patients; 306 patients had satisfactory antibody levels on first blood sample in year 1, rising to 405 in year 2; 43 patients failed to make any antibody response to Pneumovax despite multiple immunisations, and three patients failed to respond to Hib vaccine. Sixteen patients with satisfactory antibody levels in year 1 had low levels in year 2 requiring vaccine boosters. Sixteen deaths were reported, two of which were directly attributable to overwhelming sepsis. CONCLUSIONS: Registration has been successful and has raised awareness of the management of asplenia. Compliance with antibiotic prophylaxis and immunisation was initially poor. A potential high risk group of vaccine non-responders has been identified and poor persistence of pneumococcal antibodies has been identified which is likely to alter approaches to immunisation in asplenic patients.

Pitfalls of formalin fixation for determination of antineutrophil cytoplasmic antibodies.

Sera can produce nuclear or perinuclear immunofluorescence staining in neutrophils which may be caused by antibodies with differing antigenic specificities. These include perinuclear antineutrophil cytoplasmic antibodies (P-ANCA), granulocyte specific antinuclear antibody (GS-ANA), and antinuclear antibody (ANA). There is controversy over the value of formalin fixation of neutrophils in differentiating antibodies giving selective or preferential reaction with the nuclear or perinuclear area of neutrophils. In a comparative study of 77 sera, formalin fixation caused inconsistency, nonspecific effects, and false positivity owing to enhanced fluorescence. If formalin fixed neutrophils are used in the routine diagnostic laboratory, this will add confusion to the interpretation of the ANCA assay.

Treatment of EBV driven lymphoproliferation with erythrophagocytosis: 12 year follow up.

This is a report of a case of Epstein-Barr virus (EBV) associated haemophagocytic syndrome in a 17 year old woman with antibody deficiency. For two years before this presentation, serology showed abnormally high titres to EBV early antigen, suggestive of persistent infection with EBV. She became acutely unwell with clinical features consistent with virus associated haemophagocytic syndrome (VAHS). Histology showed lymphoproliferation with erythrophagocytosis and evidence of EBV encoded RNAs in liver, spleen, and lymph node. VAHS is often fatal, particularly when it occurs in patients with underlying immunodeficiencies. In this case, treatment with intravenous immunoglobulin, aciclovir, and alpha interferon was followed by a dramatic recovery. Twelve years later the patient remains relatively well on regular intravenous immunoglobulin.

Progressive multifocal leucoencephalopathy, sclerosing cholangitis, bronchiectasis and disseminated warts in a patient with primary combined immune deficiency.

A 24 year old man presented with an unusual primary combined immune deficiency syndrome characterised by a profound lymphopenia of CD4 cells, selective serum IgG2 subclass deficiency, poor polysaccharide antibody responses, disseminated warts, recurrent sinopulmonary infection and bronchiectasis. The developed progressive multifocal leucoencephalopathy (PML) in association with sclerosing cholangitis. Progressive multifocal leucoencephalopathy (PML) usually occurs as an opportunistic infection in patients with secondary defects in cellular immunity.

Common variable immunodeficiency: an update on therapeutic approaches.

Common variable immunodeficiency (CVID) is not a homogeneous disease, as has become clear from recent scientific studies. This makes the interpretation of studies of clinical therapeutics difficult to assess and raises questions about historical case reports. The evidence for the optimum use of replacement immunoglobulin in CVID is reviewed. This therapy represents the current gold standard, despite attempts to use other immunostimulatory compounds. Questions of product properties, product selection, adverse events and infectious risks are addressed. Products are not interchangeable and have different physicochemical characteristics. Despite intravenous immunoglobulin being in use for 20 years, there are still unanswered questions over dose and target trough IgG levels, particularly with respect to patients with established lung disease. The management of organ-based complications of CVID is discussed. This includes the treatment of unusual infections such as mycoplasmas and enteroviruses, which are specific to antibody deficiency. The diagnosis and treatment of the granulomatous disease of CVID is discussed. The role of surgery, including lung transplantation, in the management of CVID complications is reviewed. There are few available data on optimum strategies for antibiotic usage for bacterial infective complications and it is clear that present regimens, at least in severe recurrent sinus disease, are not consistently effective. Better clinical trials are required to identify appropriate regimens and validate or disprove widely held assumptions about therapy in CVID. Despite advances in diagnosis and management, there is abundant evidence in the UK that patients do not yet receive rapid diagnosis and optimum therapy, even within the limited published data currently available. This leads to considerable avoidable morbidity and mortality.