Andrew McLean-Tooke

Sulphadiazine-induced renal stones in a 63-year-old HIV-infected man treated for toxoplasmosis

A 63-year-old man was admitted for investigation of blurred vision and multiple ring-enhancing lesions on cranial MRI. Histopathological examination of tissue obtained at brain biopsy showed multiple Toxoplasma gondii cysts. He was started on a combination of sulphadiazine and pyrimethamine for cerebral toxoplasmosis and was subsequently diagnosed with HIV-1 infection. He then developed acute renal failure and flank pain and was diagnosed with bilateral vesico-uretric calculi requiring bilateral stent insertion. The retrieved renal calculi were negative for the common stones that are routinely tested for in our laboratory and had the macroscopic characteristics of a sulphadiazine stone. His renal failure responded to cessation of the sulphadiazine.

Differences between total IgG and sum of the IgG subclasses in clinical samples

Aims: IgG subclasses measurement is used in the investigation of patients with immunodeficiency and autoimmune diseases. In some patients a significant discrepancy between the sum of IgG subclasses (IgGsum) and total IgG may be seen. This study aimed to assess frequency and degree of such discrepancies in routine samples. Methods: Data were collected retrospectively from 571 consecutive IgG subclass samples performed by an nephelometric/turbidimetric assay. Total IgG measurement was performed by nephelometry or turbidimetry. Fifty prospective samples with a difference between the IgGsum and total IgG >15% were re-run at dilution. Results: IgGsum was a mean of 3.7% higher than the total IgG. Sixty-two samples (10.9%) had a difference between IgGsum and total IgG of >15%. Difference between IgGsum and total IgG correlated with the proportion but not level of IgG1. Repeat testing at dilution of samples with differences >15% did not significantly reduce the difference between results. Conclusions: Differences of >15% between IgGsum and total IgG are common. Using an adjusted range based on our data would reduce the number of samples requiring additional testing. Samples falling outside this range should be reviewed.

Diagnostic performance of a commercial immunoblot assay for myositis antibody testing

The objective of this study was to establish a population based reference range for a commercial immunoblot assay detecting myositis specific autoantibodies (MSAs) and myositis associated autoantibodies (MAAs), and to assess the diagnostic performance of this reference range against the manufacturers recommended ranges in a myositis patient cohort. A total of 124 patients from a myositis cohort and 197 healthy controls were serologically assessed using a commercial immunoblot containing eleven autoantigens (Jo-1, EJ, OJ, PL7, PL12, Mi-2, SRP, Ku, PMScl75, PMScl100 and Ro52) according to the manufacturers instructions. Use of the manufacturers reference ranges resulted in detection of MSAs in 19.4% of myositis patients and 9.1% of controls; MAAs were detected in 41.1% of myositis patients and 14.2% of controls. Reference values derived from the healthy control population resulted in significant differences in cut-off values for some autoantibodies, particularly Ro52 and PMScl75. Use of local reference ranges reduced detection of MSAs to 16.9% of myositis patients and 3% of healthy controls, with MAAs 23.4% of patients and 2% of healthy controls. Application of population based reference ranges resulted in significant differences in detection of MSAs and MAAs compared to the manufacturers recommended ranges. Cut-off levels should be assessed to ensure suitability for the population tested.

Sjögren Syndrome With Associated Lymphocytic Interstitial Pneumonia Successfully Treated With Tacrolimus and Abatacept as an Alternative to Rituximab

Interstitial lung disease (ILD) is a significant complication of Sjögren syndrome (SS) associated with increased morbidity and mortality. The mainstay of treatment remains corticosteroid administration, with or without additional immunosuppressive therapies. Preliminary studies in SS have shown benefit in glandular and serologic parameters following treatment with the CTLA4 immunoglobulin fusion protein abatacept. Topical tacrolimus has been effective for ocular symptoms in SS, but systemic therapy has not been reported. We describe the first case, to our knowledge, of the successful use of a combination of systemic tacrolimus and abatacept in severe refractory SS and related ILD.

Prevalence of anti-aquaporin 4 antibody in a diagnostic cohort of patients being investigated for possible neuromyelitis optica spectrum disorder in Western Australia

OBJECTIVE To evaluate the prevalence of anti-AQP4 antibody in serum and CSF samples from patients being investigated for possible neuromyelitis optica spectrum disorder (NMOSD) referred to the PathWest State reference laboratory using a sensitive cell-based assay (CBA). BACKGROUND NMOSD is an inflammatory CNS disease distinct from MS, which is relatively rare in Western countries. A proportion of patients with NMOSD have detectable serum IgG antibodies that target the water channel aquaporin-4 (AQP4-IgG), but the frequency varies in different populations studied and according to the assay method employed. METHODS Sera or CSF from a diagnostic cohort of 196 consecutive patients with possible NMOSD which had previously been screened by indirect immunofluorescence (IIF) on primate cerebellum were re-tested for AQP4-IgG reactivity to the M1 and M23 isoforms of AQP4 using a commercial CBA. A control group of 205 patients with definite MS was also included in the study. RESULTS Of the 196 patients, only 5 sera were AQP4-IgG positive, representing 2.6% of patients in the diagnostic cohort. All 5 AQP4-IgG positive patients fulfilled the 2015 revised diagnostic criteria for NMOSD and were females of varied ethnic origins, 4 of whom had longitudinally extensive transverse myelitis. The CBA confirmed AQP4-IgG positivity in the four patients previously reported as positive by IIF, and an additional patient with NMOSD who had previously been diagnosed as MS was also identified. None of the 205 MS sera were AQP4-IgG positive. CONCLUSIONS Our study confirms the utility and greater reliability of the M1/M23 CBA for detecting AQP4-IgG in patients with possible NMOSD, and indicates a prevalence of seropositive NMOSD in the Western Australian population similar to that in other Western populations.

Fulminant Anti-GAD antibody encephalitis presenting with status epilepticus requiring aggressive immunosuppression

Antibodies against glutamic acid decarboxylase (GAD) are reported in association with numerous neurological conditions including temporal lobe epilepsy and limbic encephalitis. We report a case of Anti-GAD-Antibody associated encephalitis presenting with epilepsia partialis continua (EPC) progressing to a fulminant encephalopathy preferentially affecting the frontal lobes associated with coma and refractory status epilepticus. The abnormalities identified on MRI included marked bilateral frontal lobe involvement which has not been reported in other auto-immune encephalitides and may be specific for Anti-GAD-Antibody associated encephalitis. Similar to the majority of cases of Anti-GAD associated neurological disturbance no underlying malignancy was identified. Treatment with high dose corticosteriods, IVIG and plasmapheresis had minimal response, but escalation of treatment with rituximab and cyclophosphamide was associated with clinical improvement, reducing antibody titers and resolution of MRI changes.

Long-term control of laryngeal plasma cell mucositis with systemic immunosuppression

Plasma cell mucositis (PCM) is a rare non-neoplastic plasma cell proliferative disorder of the mucous membranes, which typically presents as soft tissue lesions involving oral, upper airway or genital mucosa. Laryngeal involvement resulting in stridor has been reported in four other cases previously, with three requiring tracheostomy. We present a case of supraglottic stenosis in a 53-year-old woman presenting with dysphonia and stridor, requiring surgical resection on three occasions accompanied by tracheostomy on two occasions; biopsy was consistent with PCM. Due to relapsing disease activity, high-dose prednisolone and mycophenolate mofetil were commenced with prednisolone eventually being ceased. After 2 years of mycophenolate mofetil therapy, the patient’s disease has been controlled without need for further surgical intervention. This is the first reported case of prolonged symptomatic improvement with the use of systemic immunosuppressive therapy with mycophenolate mofetil in PCM.

The role of immunological testing and intervention in reproductive medicine: A fertile collaboration?

Advances in reproductive medicine have significantly increased the success of fertility treatments. Nevertheless, some women experience recurrent implantation failure (RIF) after in‐vitro fertilization (IVF) or recurrent pregnancy loss (RPL). Imbalances in the immune system and failure to achieve immune tolerance to the foetus have been implicated as potentially modifiable causes of idiopathic RIF and RPL. As such, women are increasingly being treated with immunomodulatory agents in an attempt to achieve a successful pregnancy. This systematic review examines the published evidence on immune changes in these patients, the use of immunomodulation therapies and diagnostic testing modalities to guide their use or to identify patient subsets most likely to benefit. The PubMed database was searched for the terms “recurrent implantation failure” and “recurrent pregnancy loss” in conjunction with T‐helper (Th) cells and their subsets in particular; Th1, Th2, Th17 and T‐regulatory (Treg) cells, natural killer (NK) cells, cytokine imbalance as well as immune modulators and immune suppressants. The reference lists of articles were examined to identify additional articles. There remains limited data on the immunological changes in cytokine and cellular profiles during the hormonal cycle as well as prior to, during and after implantation in health as well as idiopathic RIF and RPL. There is a need to advance immunological diagnostics to match the clinical need in this emerging field and to guide clinicians to make optimal and safe therapeutic choices. It is also imperative that the well‐being of the infants conceived after such intervention is monitored.

B-cell small lymphocytic lymphoma associated with extremely high total IgE and cutaneous vasculitis

Extremely elevated polyclonal lgE of unknown etiology may indicate the presence of unsuspected B-cell lymphoma. In our patient, treatment of the lymphoma correlated with a reduction in serum lgE and complete resolution of the cutaneous vasculitis.