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Summary Coronavirus 19 (COVID‐19) has been associated with both transient and persistent systemic symptoms that do not appear to be a direct consequence of viral infection. The generation of autoantibodies has been proposed as a mechanism to explain these symptoms. To understand the prevalence of autoantibodies associated with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, we investigated the frequency and specificity of clinically relevant autoantibodies in 84 individuals previously infected with SARS‐CoV‐2, suffering from COVID‐19 of varying severity in both the acute and convalescent setting. These were compared with results from 32 individuals who were on the intensive therapy unit (ITU) for non‐COVID reasons. We demonstrate a higher frequency of autoantibodies in the COVID‐19 ITU group compared with non‐COVID‐19 ITU disease control patients and that autoantibodies were also found in the serum 3–5 months post‐COVID‐19 infection. Non‐COVID patients displayed a diverse pattern of autoantibodies; in contrast, the COVID‐19 groups had a more restricted panel of autoantibodies including skin, skeletal muscle and cardiac antibodies. Our results demonstrate that respiratory viral infection with SARS‐CoV‐2 is associated with the detection of a limited profile of tissue‐specific autoantibodies, detectable using routine clinical immunology assays. Further studies are required to determine whether these autoantibodies are specific to SARS‐CoV‐2 or a phenomenon arising from severe viral infections and to determine the clinical significance of these autoantibodies., Acute infection with COVID is associated with a pattern of autoantibodies including a high proportion with epidermal antibodies. This autoantibody pattern is more common in severe COVID and is persistent up to 6 months.

COVID-19 has been associated with both transient and persistent systemic symptoms that do not appear to be a direct consequence of viral infection. The generation of autoantibodies has been proposed as a mechanism to explain these symptoms. To understand this phenomenon in more detail, we investigated the frequency and specificity of clinically relevant autoantibodies in 84 individuals previously infected with SARS-CoV-2, suffering from COVID-19 of varying severity in both the acute and convalescent setting. These were compared with results from 32 individuals who were on ITU for non COVID reasons. We demonstrate a higher frequency of autoantibodies in the COVID-19 ITU group compared with non-COVID-19 ITU disease control patients and that autoantibodies were also found in the serum 3-5 months post COVID-19 infection. Non-COVID patients displayed a diverse pattern of autoantibodies; in contrast, the COVID-19 groups had a more restricted panel of autoantibodies including skin, skeletal muscle and cardiac antibodies. Our results demonstrate that severe COVID-19 induces a pattern of autoantibodies that may correlate with and contribute to the immune pathology associated with the long-term sequelae of infection.

PROBLEM Pre-eclampsia (PE) is a leading cause of maternal and foetal morbidity worldwide. Given the implication of immune mechanisms, we compared markers of humoral immunity in PE and their relationship to circulating markers of inflammation, angiogenic factors, and renal function. METHOD OF STUDY Serum samples from 88 previously healthy women admitted to hospital with PE and 107 healthy pregnant controls at term were analysed for serum immunoglobulins (Ig), including IgG subclasses and free light chain (sFLC) levels, beta-2 microglobulin (B2-M), high-sensitivity C-reactive protein (HS-CRP), albumin, complement proteins (C3 & C4), creatinine, cystatin-C and the ratio of soluble fms-like tyrosine kinase-1 (sFLT-1) and placental growth factor (PlGF). RESULTS Compared to the controls, women with PE had significantly reduced renal function, serum IgG (subclass 1 & 3), albumin, and C4 levels, whilst concentrations of total sFLC, HS-CRP, B2-M, and sFLT-1:PlGF were raised. On multivariable analysis, sFLT-1:PlGF ratio (P

Background There is a paucity of data on paediatric kidney disease in developing countries such as Malawi. Descriptive research on kidney disease is essential to improving patient outcomes. Methods We conducted a cross-sectional study at a tertiary hospital in Malawi from 2012 to 2013. Children under 14 years with proteinuric kidney disease were enrolled from paediatric wards and outpatient clinics at Queen Elizabeth Central Hospital (QECH). Demographic, clinical and laboratory data were collected from patients at enrolment and at 3 months review at which point clinical status and disease outcome were ascertained. Results Thirty-four (22 male) patients were studied, mean age 8.54 (SD = 3.62 years). Glomerular disease (n = 25, 68%) was the most common presumed renal lesion at presentation. Nephritic syndrome (10) was characterised by a lower baseline complement C3 than nephrotic syndrome (p = 0.0027). Seven (47%) cases of nephrotic syndrome achieved complete remission. Eight (80%) cases of nephritic syndrome improved with supportive therapy. Nineteen (56%) patients presented with clinically significant renal damage with eGFR

Non-cirrhotic intrahepatic portal hypertension (NCIPH) is generally regarded to have a benign prognosis. We have studied a cohort followed-up at a tertiary referral center and postulate that gut-derived prothrombotic factors may contribute to the pathogenesis and prognosis of NCIPH. We retrospectively analyzed prognostic indicators in 34 NCIPH patients. We also searched for associated gut diseases. Transplant-free survival in NCIPH patients from first presentation with NCIPH at 1, 5, and 10 years was 94% (SE: 4.2%), 84% (6.6%), and 69% (9.8%), respectively. Decompensated liver disease occurred in 53% of patients. Three (9%) patients had ulcerative colitis while five of 31 (16%) tested had celiac disease and on Kaplan–Meier analysis, celiac disease predicted reduced transplant-free survival (p = 0.018). On multivariable Cox regression analysis, independent predictors of reduced transplant-free survival were older age at first presentation with NCIPH, hepatic encephalopathy, and portal vein thrombosis. Prevalence of elevated initial serum IgA anticardiolipin antibody (CLPA) was significantly higher in NCIPH (36% of patients tested), compared to Budd–Chiari syndrome (6%) (p = 0.032, Fisher’s exact test) and celiac disease without concomitant liver disease (0%) (p = 0.007). We have identified prognostic factors and report progression to liver failure in 53% of NCIPH patients followed-up at our center. Our data supports a role for intestinal disease in the pathogenesis of intrahepatic portal vein occlusion leading to NCIPH.

OBJECTIVE Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA) have been reported to be pathologically and clinically different. The aim of this study was to assess whether these differences could be explained by differing abilities of proteinase 3-antineutrophil cytoplasmic antibody (PR3-ANCA)-positive IgG preparations or myeloperoxidase-ANCA (MPO-ANCA)-positive IgG preparations to activate neutrophils (polymorphonuclear cells [PMN]) in vitro. METHODS Using Percoll density gradients, PMN were isolated (concentration 2 x 10(6)/ml) and primed with cytochalasin B (1 ng/ml) and tumor necrosis factor alpha (TNFalpha; 2 ng/ml). The PMN were activated with 200 microg/ml of normal IgG or ANCA. Activation was determined by 1) superoxide anion generation as determined by the superoxide dismutase-inhibitable reduction of ferricytochrome c, 2) monitoring fluxes in Ca2+ concentration using Fura 2-AM-loaded PMN, and 3) degranulation using an MPO assay. Surface expression of PR3 and MPO was determined by fluorescence-activated cell sorter analysis. ANCA isotypes were investigated by enzyme-linked immunosorbent assay. RESULTS Activation of PMN by MPO-ANCA-positive IgG preparations compared with PR3-ANCA-positive IgG preparations resulted in greater generation of superoxide anions (MPO-ANCA-positive IgG preparations 9.13 +/- 0.39 nmoles [mean +/- SEM], PR3-ANCA-positive IgG preparations 6.32 +/- 0.35 nmoles; P < 0.001), Ca2+ fluxes (MPO-ANCA-positive IgG preparations 0.735 +/- 0.10, PR3-ANCA-positive IgG preparations 0.33 +/- 0.098; P < 0.01), and MPO degranulation (MPO-ANCA-positive IgG preparations 251.98 +/- 26.7 ng, PR3-ANCA-positive IgG preparations 145.19 +/- 19.4 ng; P < 0.001). The increased activation seen with MPO-ANCA-positive IgG preparations was not due to increased expression of MPO on the cell surface, because following TNFalpha priming PR3 was expressed on significantly more cells than was MPO (PR3 expression 54.2 +/- 5.18%, MPO 31.6 +/- 3.55%; P < 0.001). IgG1 and IgG4 were the predominant isotypes in both MPO-ANCA-positive IgG preparations and PR3-ANCA. MPO-ANCA contained significantly more IgG1 than did PR3-ANCA, and PR3-ANCA-positive IgG preparations contained significantly more IgG3. CONCLUSION In vitro MPO-ANCA-positive IgG preparations are more activating than PR3-ANCA-positive IgG preparations. The increased activation cannot be explained by increased MPO expression on the cell surface or greater IgG3 present in MPO-ANCA-positive IgG preparations. Differences in activation of PMN by these antibodies may determine some differences between WG and MPA.

The Ca(2+)-permeation properties of AMPA-receptor (AMPA-R) channels in Purkinje neurons in rat cerebellar slices were studied using a combination of whole-cell patch-clamp recordings, Fura-2 fluorometry, and single-cell reverse-transcription (RT)-PCR. Several lines of evidence indicate that Purkinje neurons, at both early and late stages of postnatal development, express exclusively AMPA-R channels with a low Ca2+ permeability. First, no Ca2+ signal was detected during application of either AMPA or kainate to Purkinje neurons loaded with the Ca2+ indicator Fura-2 AM. In contrast, kainate application induced large Ca2+ transients in Bergmann glia cells. Second, in ion substitution experiments, when Ca2+ is the only extracellular permeant cation, the reversal potential corresponds to that expected for AMPA-R channels with a low permeability for Ca2+. Third, using a fluorometric flux-measurement approach (Schneggenburger et al., 1993a), we found that the Ca2+ fraction of the total cation current through AMPA-R channels is approximately 0.6%. This value is approximately sixfold lower than that found for recombinant AMPA-R lacking the AMPA-R subunit GluR2. Furthermore, single-cell RT-PCR experiments revealed the presence of the AMPA-R subunits GluR1, GluR2, and GluR3 in Purkinje neurons in cerebellar slices at developmental stages corresponding to those studied electrophysiologically. The expression of GluR2 in all cells tested (n = 14) is consistent with the subunit composition predicted from studies of recombinant AMPA-R channels with a low permeability for Ca2+ (Burnashev et al., 1992b). In conclusion, this study establishes that cerebellar Purkinje neurons at all postnatal developmental stages possess AMPA-R channels with a low permeability for Ca2+.

Objectives: To determine whether otitis media with effusion (OME) is associated with elevated serum immunoglobulin E (IgE) and IgE specific for house dust mite. Design: Forty-seven children who had evidence of bilateral OME, both otoscopically and on tympanometry, on two separate occasions, 3 months apart were admitted for ventilation tubes. Forty-eight children admitted for minor eye surgery who had otoscopically normal ears and no history of middle ear problems were used as controls. Bloods samples were taken under anaesthesia. Total IgE and IgE radioallergosorbent test (RAST) to house dust mite was measured by the Pharmacia Unicap 100 system. The results from the two groups were compared. Setting: Birmingham Children's Hospital. Participants: Children between the ages of 3 and 10. Children with Down's syndrome, cleft lip and palate, ciliary abnormalities, known immunodeficiencies and cardiac abnormalities were excluded. Main outcome measures: Total IgE and RAST to house dust mite. A RAST of >0.35 was taken to be positive. Results: There was no statistical difference between the control and study groups for the total IgE. Six children from both study and control groups had a raised house dust mite RAST. There was no difference in the levels between either group. Conclusions: Our findings indicate that there is no direct relationship between OME and biochemical evidence of allergy, specifically to house dust mite.

Monoclonal κ and λ immunoglobulin free light chain (FLC) paraproteins in serum and urine are important markers in the diagnosis and monitoring of B cell dyscrasias. Current nephelometric and turbidimetric methods that use sheep polyclonal antisera to quantify serum FLC have a number of well-observed limitations. In this report, we describe an improved method using specific mouse anti-human FLC monoclonal antibodies (mAbs). Anti-κ and anti-λ FLC mAbs were, separately, covalently coupled to polystyrene Xmap® beads and assayed, simultaneously, in a multi-plex format by Luminex® (mAb assay). The mAbs displayed no cross-reactivity to bound LC, the alternate LC type, or other human proteins and had improved sensitivity and specificity over immunofixation electrophoresis (IFE) and Freelite™. The assay gives good linearity and sensitivity (