Pulmonary granulomas in a patient with positive ANCA and history of tuberculosis: case report

BACKGROUND

Granulomatous polyangiitis (GPA) is a rare multisystem autoimmune disease of unknown aetiology that is pathologically characterised by necrotising vasculitis, tissue necrosis and granulomatous inflammation, typically in the presence of anti-neutrophil cytoplasmic antibodies (ANCA). However infectious diseases may induce high titre ANCA and mimic vasculitis. Tuberculosis may share many clinical features with GPA including fever, arthralgia, granulomatous inflammation and pulmonary lesions and patients.

CASE PRESENTATION

A 39 year old patient was admitted with ocular irritation and redness, arthralgia and multiple new pulmonary lesions. The past medical history was significant for two episodes of tuberculosis previously requiring prolonged treatment. ANCA antibodies were positive and CT showed multiple pulmonary lesions including cavitatory lesions. After extensive investigation, the patient was treated for GPA with high dose immune suppression with good clinical response.

CONCLUSIONS

Here we review the diagnostic considerations between differentiating GPA and tuberculosis in patients from endemic regions. It is recommended that biopsies of lung lesions, sputum microscopy and multidisciplinary team input are sought as part of the workup when these two differentials are being considered.

The revolving door: antibiotic allergy labelling in a tertiary care centre

BACKGROUND

Patients frequently report antibiotic allergies; however, only 10% of labelled patients have a true allergy.

AIM

We investigated the documentation of antibiotic 'allergy' labels (AAL) and the effect of labelling on clinical outcomes, in a West Australian adult tertiary hospital.

METHODS

Retrospective cross-sectional analysis of patients captured in the 2013 and 2014 National Antimicrobial Prescribing Surveys was carried out. Data were collected on documented antibiotic adverse drug reactions, antibiotic cost, prescribing appropriateness, prevalence of multi-drug resistant organisms, length of stay, intensive care admission and readmissions.

RESULTS

Of the 687 patients surveyed, 278 (40%) were aged 70 or above, 365 (53%) were male and 279 (41%) were prescribed antibiotics. AAL were recorded in 122 (18%) patients and the majority were penicillin labels (n = 87; 71%). Details of AAL were documented for 80 of 141 (57%) individual allergy labels, with 61 describing allergic symptoms. Patients with beta-lactam allergy labels received fewer penicillins (P = 0.0002) and more aminoglycosides (P = 0.043) and metronidazole (P = 0.021) than patients without beta-lactam labels. Five patients received an antibiotic that was contraindicated according to their allergy status. Patients with AAL had significantly more hospital readmissions within 4 weeks (P = 0.001) and 6 months (P = 0.025) of discharge, compared with unlabelled patients. The majority (81%) of readmitted labelled patients had major infections.

CONCLUSIONS

AAL are common, but poorly documented in hospital records. Patients with AAL are significantly more likely to require alternative antibiotics and hospital readmissions. There may be a role for antibiotic allergy delabelling to mitigate the clinical and economic burdens for patients with invalid allergy labels.

Mutations in CHD7 in patients with CHARGE syndrome cause T-B + natural killer cell + severe combined immune deficiency and may cause Omenn-like syndrome

More than 11 genetic causes of severe combined immunodeficiency (SCID) have been identified, affecting development and/or function of T lymphocytes, and sometimes B lymphocytes and natural killer (NK) cells. Deletion of 22q11.2 is associated with immunodeficiency, although less than 1% of cases are associated with T-B + NK + SCID phenotype. Severe immunodeficiency with CHARGE syndrome has been noted only rarely Omenn syndrome is a rare autosomal recessive form of SCID with erythroderma, hepatosplenomegaly, lymphadenopathy and alopecia. Hypomorphic recombination activating genes 1 and 2 mutations were first described in patients with Omenn syndrome. More recently, defects in Artemis, RMRP, IL7Ralpha and common gamma chain genes have been described. We describe four patients with mutations in CHD7, who had clinical features of CHARGE syndrome and who had T-B + NK + SCID (two patients) or clinical features consistent with Omenn syndrome (two patients). Immunodeficiency in patients with DiGeorge syndrome is well recognized--CHARGE syndrome should now be added to the causes of T-B + NK + SCID, and mutations in the CHD7 gene may be associated with Omenn-like syndrome.

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.

Immunodeficiency and autoimmunity in 22q11.2 deletion syndrome

22q11.2 deletion syndrome is the commonest chromosome deletion syndrome. 22q11.2 deletion may result in variable clinical phenotypes which may differ even between patients with identical deletions. Abnormal pharyngeal arch development results in defects in the development of the parathyroid glands, thymus and conotruncal region of the heart. Defective thymic development is associated with impaired immune function. 'Complete' DiGeorge syndrome with total absence of the thymus and a severe T-cell immunodeficiency accounts for <0.5% of patients. The majority of patients with 22q11.2 deletion syndromes have 'partial' defects with impaired thymic development rather than complete absence with variable defects in T-cell numbers. Immunodeficiency in these patients is not solely due to T-cell deficiency and abnormalities of T-cell clonality or impairment of proliferative responses may play a role. Humoral deficiencies including defects in the B-cell compartment have also been identified in these patients. 22q11.2 deletion syndrome patients are at increased risk of a variety of autoimmune diseases. A number of immune defects may predispose to the development of autoimmunity in these patients including increased infection, impaired development of natural T-regulatory cells and impaired thymic central tolerance.