Polyarthritis, rash and lymphadenopathy: Case reports of two patients with angioimmunoblastic lymphadenopathy presenting to a rheumatology clinic

Two patients presented with a symmetrical inflammatory polyarthropathy. Both patients fulfilled the diagnostic criteria for angioimmunoblastic lymphadenopathy. We present the two case histories and review the current literature. Although an uncommon disease, the diagnosis of angioimmunoblastic lymphadenopathy should be considered in a patient presenting with polyarthritis and skin rash.     

Unique and recurrent WAS gene mutations in Wiskott-Aldrich syndrome and X-linked thrombocytopenia

Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) are allelic phenotypes caused by defects of the WAS gene. Fourteen distinct mutations including seven novel gene defects in 16 WAS and four XLT patients were identified by single strand conformation polymorphism analysis and DNA sequencing of the WAS gene. Eleven (79%) of these mutations are located within exons 1 to 4 with clustering in exon 2. Carrier detection in 33 at-risk females and prenatal diagnosis at 12 weeks gestation in one family with a novel WAS mutation was performed by direct mutation analysis. A remarkably high frequency (72%) of point mutations involved CpG dinucleotides. C-->T or G-->A transitions at CpG sites were identified in all isolated WAS cases (n = 7). Allele frequencies for the dinucleotide repeat at locus DXS6940 were determined in Northern European, African and Asian populations. Mutation screening alone or in combination with analysis of polymorphic loci DXS6940 and DXS255 delineated the germline origin of a unique insertion mutation and four recurrent CpG mutations, three of which arose spontaneously during maternal gametogenesis.     

Monoclonal antibodies that recognize human granulocyte-macrophage colony-stimulating factor and neutralize its bioactivity in vitro.

We have produced monoclonal antibodies to bacterially synthesized, human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and have studied in detail the characteristics of three strongly neutralizing antibodies. The antibodies reacted with GM-CSF at high dilution (EC50 = 0.1-1.7 nM) in an indirect ELISA but did not react with murine GM-CSF or other cytokines. They also recognized glycosylated hGM-CSF produced by human lymphocytes. The antibodies were able to immunoprecipitate rhGM-CSF, but only reacted weakly with rhGM-CSF on Western blots, indicating that they recognized a conformation-dependent epitope. Cross-blocking studies showed that the three antibodies recognized overlapping epitopes. The antibodies inhibited binding of 125I-labeled rhGM-CSF to HL-60 cells at nanomolar concentrations and neutralized GM-CSF activity in two different bioassays. These antibodies thus provide a useful tool for analyzing the specificity of bioassays and for further studies of the production and function of GM-CSF in vitro and in vivo.     

Leg ulceration and ethnicity: a study in west London

Little is known of the influence race has on the development of leg ulceration, with most studies being performed in almost exclusively white populations. As part of a wider audit of leg ulcer services, health care professionals were contacted to give details of age, sex and ethnic background of all patients who attended for treatment of leg ulceration over a one year period in an area of west London. West London Health Care Trust provides services to a population of 275000 of whom 53000 have an ethnic background from the Indian subcontinent (South Asian).In all, 280 patients were identified, of whom 264 (94%) had details of age and sex. This gave a crude ascertainment rate of 1.02 per 1000 population. Of the 264 patients, five were classified as South Asians, with one patient classified as Afro-caribbean. The Mantel Haenzsel test demonstrated a significantly higher proportion of whites suffering from leg ulceration than South Asians, giving an odds ratio of 4.43, with 95% confidence intervals between 1.94 and 10.13 (P=0.0004). The expected frequency of South Asian patients should be 23, based on rates from the white population, of which 13 would be women and 10 men. Only five South Asian men were identified, and no Asian women with leg ulceration.Reasons for this low ascertainment are two-fold. Either there is a real difference between the white and South Asian populations, or South Asian patients are not presenting for treatment. Further work must be performed to determine whether this is an effect of low prevalence, or unmet need in the community.