Calcium pyrophosphate deposition disease: a frequent finding in patients with long-standing erosive gout.

OBJECTIVE: To characterize patients with both monosodium urate (MSU) and calcium pyrophosphate (CPP) crystals in their synovial fluid (SF). METHOD: Forty-nine gout patients with acute arthritis were included. Those patients with MSU crystals only in their SF were compared to those patients with both MSU and CPP crystals in their SF. RESULTS: A total of 36 out of 49 patients (73.5%) had only MSU crystals, whereas 13 out of 49 (26.5%) had both MSU and CPP crystals in their SF. Co-deposition of CPP crystals was associated with long-standing gout disease (p = 0.022), kidney dysfunction (p = 0.024), and erosive arthritis (p = 0.049), but not with age. CONCLUSION: Long-standing gout may be a risk factor for CPP deposition disease, and the frequency of CPP co-deposition may be higher than expected.

Low immunoglobulin E flags two distinct types of immune dysregulation.

During the last two decades, hyper-immunoglobulin (Ig)E syndromes have been characterized clinically and molecularly in patients with genetically determined primary immunodeficiencies. However, the detection of low IgE levels, defined here as below detection limit in the routine clinical immunology laboratory, has received little attention. We analysed the association of serum IgA, IgM and IgG levels (including IgG subclasses) with low, normal or high serum IgE levels in patients evaluated in a single-centre out-patient immunodeficiency and allergy clinic. The correlation of serum IgE levels with IgG subclasses depended on the clinical phenotype. In patients with immunodeficiencies, IgE correlated with IgG2 and IgG4 but not with IgG3. In contrast, in patients referred for signs of allergy, IgE correlated with IgG3 but not with IgG2. A low IgE result was associated with low IgG3 and IgG4 in allergy referrals, while immunodeficiency referrals with a low IgE result had significantly lower IgG1, IgG2 and IgG4 levels. Hierarchical clustering of non-IgE immunoglobulin profiles (IgM, IgA, IgG, IgG1-4) validated that non-IgE immunoglobulin levels predict the clinic referral, i.e. phenotype, of low-IgE patients. These results suggesto guide the clinical management of patients with low serum IgE levels.

Risk factors for pneumocystis pneumonia in giant cell arteritis: a single-centre cohort study.

OBJECTIVES: Pneumocystis jiroveci pneumonia (PCP) is a life-threatening opportunistic infection. Few PCP cases in giant cell arteritis (GCA) have been described, but it remains unknown, which patients need PCP prophylaxis. METHODS: Sixty-two patients with GCA from a prospective cohort were studied to identify treatment-related predictors of PCP infection. RESULTS: Four PCP infections occurred, all in patients treated with methotrexate in addition to prednisone. Moreover, PCP is associated with higher cumulative PDN doses and severe lymphocytopenia (<400/µl). CONCLUSIONS: Our findings support PCP-prophylaxis in GCA patients who are treated with methotrexate and PDN, and need high prednisone doses to achieve remission, or develop severe lymphocytopenia.

The ultrasound compression sign to diagnose temporal giant cell arteritis shows an excellent interobserver agreement.

OBJECTIVES: To compare the diagnostic performance between a vascular specialist and a rheumatologist not familiar with vascular ultrasound when applying the compression sign for the diagnosis of temporal arteritis. METHODS: Sixty consecutive patients with suspicion of giant cell arteritis were examined by both examiners. Compression of the temporal artery on both sides (stem and both branches) was performed to define whether signs of vasculitis, no vasculitis or an indefinite result were present. Each examiner was blinded to the result of the other. RESULTS: In 59/60 patients, the examiners found an identical result. The interobserver agreement (Krippendorf alpha) was 0.92. CONCLUSIONS: The new compression sign for the diagnosis of temporal arteritis is a simple and robust sonographic marker with an excellent interobserver agreement.

Altered distribution of mucosal NK cells during HIV infection.

The human gut mucosa is a major site of human immunodeficiency virus (HIV) infection and infection-associated pathogenesis. Increasing evidence shows that natural killer (NK) cells have an important role in control of HIV infection, but the mechanism(s) by which they mediate antiviral activity in the gut is unclear. Here, we show that two distinct subsets of NK cells exist in the gut, one localized to intraepithelial spaces (intraepithelial lymphocytes, IELs) and the other to the lamina propria (LP). The frequency of both subsets of NK cells was reduced in chronic infection, whereas IEL NK cells remained stable in spontaneous controllers with protective killer immunoglobulin-like receptor/human leukocyte antigen genotypes. Both IEL and LP NK cells were significantly expanded in immunological non-responsive patients, who incompletely recovered CD4+ T cells on highly active antiretroviral therapy (HAART). These data suggest that both IEL and LP NK cells may expand in the gut in an effort to compensate for compromised CD4+ T-cell recovery, but that only IEL NK cells may be involved in providing durable control of HIV in the gut.

High incidence of severe ischaemic complications in patients with giant cell arteritis irrespective of platelet count and size, and platelet inhibition.

OBJECTIVE: Vision loss and ischaemic stroke are feared complications in GCA. We investigated how platelet count and size and platelet inhibition with ASA relate to ischaemic complications in patients with GCA. METHODS: Charts of patients with GCA were retrospectively analysed. Jaw claudication, amaurosis fugax, blurred vision, ischaemic stroke and permanent visual loss were classified as 'ischaemic events'; ischaemic stroke and permanent visual loss were sub-grouped as 'severe ischaemic events'. The incidence of ischaemia and the association to the pre-defined covariates age, fever, ESR, platelet count and size and ASA treatment were assessed. RESULTS: Eighty-five patients (mean age 73 yrs, 60% women, 78% biopsy-proven) were included in the analysis. Of the 85 patients, 62 (73%) presented with ischaemic events, 29/85 patients (34%) with severe ischaemic events. At the time of diagnosis 22/85 patients (26%) were treated with ASA. Of these 22 patients, 15 (68%) presented with ischaemic events, 7/22 patients (32%) with severe ischaemic events. In multivariate analysis, neither platelet count nor size or ASA treatment were significantly associated with ischaemic or severe ischaemic events. CONCLUSIONS: The incidence of severe ischaemic events in patients with GCA was high, irrespective of platelet count and size and established ASA treatment.