Familial isolated hyperparathyroidism (FIHP) is a rare heritable disorder characterized by hypercalcemia, inappropriately high PTH levels, and isolated parathyroid tumors with no evidence of hyperfunction of any other endocrine tissues. To establish whether FIHP exists as a distinct disease entity or represents a variant of any of the known multiple endocrine neoplasia (MEN) syndromes, we tested 19 members of a large, well characterized family with FIHP in which the disease is transmitted through 4 generations in an autosomal dominant fashion. Fourteen DNA markers at 10 polymorphic loci closely linked to the MEN1 locus on the long arm of chromosome 11 and 5 markers close to the MEN2A gene on chromosome 10 were tested using Southern blot analysis and polymerase chain reaction-based techniques. Additionally, two polymorphic markers (Mir1 and Mir2) within the prepro-PTH gene on the short arm of chromosome 11 were analyzed using denaturant gradient gel electrophoresis. Linkage was clearly excluded between FIHP and the MEN1 and MEN2A loci as well as to the PTH gene. Comparison of constitutional and tumor genotypes showed that constitutional heterozygosity was retained for markers in the MEN1 and MEN2A regions as well as to the PTH gene in 4 tumors from 3 affected members. In 1 individual, a parathyroid carcinoma was found after recurrence of hypercalcemia. We, therefore, propose that autosomal dominant FIHP can occur as a genetically and clinically distinct entity with an increased risk of malignant transformation of parathyroid tumors.

Chemokine receptors are expressed by many cells, including lymphoid cells, and function to mediate cell trafficking and localization. Normal B-cells have been reported to express CXCR3, CXCR4, CXCR5, CCR6 and CCR7, however changes in chemokine receptor expression during B-cell development and in B-cell lymphoproliferative disorders (BCLPDs) are incompletely understood, and could provide important information about normal B-cell development and about behavior of neoplastic B-cells. The objective was to perform a systematic study of chemokine receptor expression on B cells from normal subjects and from patients with a range of BCLPDs. Expression of the above chemokine receptors, and CCR5, were analyzed by flow cytometry on lymphocytes from normal controls (n=20), and samples of follicular centre cell lymphoma (FCCL, n=16), precursor B-acute lymphoblastic leukemia (Prec-B-ALL, n=16), chronic lymphocytic leukemia (CLL, n=21), small cell lymphocytic lymphoma (SLL, n=9), hairy cell leukemia (HCL, n=10) and other miscellaneous disorders (n=9). Normal B cells were typically positive for CXCR4, CXCR5 and CCR6, negative for CCR5 and variable for CCR7. Prec-B-ALL cells expressed CXCR4 but were negative for the other receptors. B-CLL cells lost expression of CCR6 but showed strong expression of CCR7. In contrast, SLL cells failed to express CCR7, but were otherwise similar to CLL cells. HCL cells showed absence of CXCR5 and CCR7, but interestingly all but one case expressed CCR5, whilst CD25-negative "variant" HCL cells did not express CCR5. FCCL cells down-regulated CXCR4 and CXCR5 expression and lost expression of CCR6 and CCR7. CXCR3 expression was highly variable on normal B-cells and on cells from BCLPDs, possibly due to its lability during processing. Distinct changes in chemokine receptor expression accompany B-cell development, whilst some BCLPDs show characteristic alterations that may be useful in phenotyping and in understanding biological behavior.

Immune deficiency diseases are often accompanied by abnormalities in one or both arms of the specific immune system. Impairment can often be detected as a decrease in the number of T or B lymphocytes or their products in the circulation, but questions are often asked as to the functional capabilities of T lymphocytes in patients with recurrent infections. Function of T cells has traditionally been measured by their uptake of [ 3 H]-thymidine following stimulation with antigen or mitogen in vitro. However, the ability of carboxyfluorescein succinimidyl ester (CFSE) to label lymphocytes intracellularly and track their mitotic activity by progressive twofold reduction in fluorescence intensity prompted an alternative methodology based on flow cytometry, an approach which has the advantage of allowing specific gating on particular T cell subsets and simultaneous assessment of activation markers. This method was therefore evaluated for T cell responses to mitogen and antigen. Phytohaemagglutinin-induced blast transformation of CFSE-labelled T cells was reflected by an increase in forward and orthogonal light scatter and a progressive two-fold decrease in CFSE fluorescence intensity. These changes allowed the derivation of various measures of mitotic activity, which correlated well with [ 3 H]-thymidine uptake. Patients with T cell functional deficiencies showed impairment in their responses by both assays, whereas the CFSE-based assay demonstrated that impaired blastogenesis was not simply due to depressed T cell numbers. Concomitant measurement of the activation markers CD69 and CD25 showed that CD69 was rapidly expressed on non-mitotic cells and that this expression was progressively diluted with subsequent rounds of cell division. In contrast, CD25 expression was unaffected by cell cycle, but was expressed in proportion to the PHA dose. Antigenspecific responsiveness to Candida was also assessed using a CFSE-based assay. Initial gating on the relatively minor population of T cells that underwent blast transformation demonstrated progressive twofold dilutions of CFSE intensity in responsive cells. These normal Candida responses, found in patients who had recovered from Candida infection, contrasted with those who had not been infected with Candida or who had chronic recurrent infection, in whom neither blast transformation nor significant mitosis could be detected. Again, there was good correlation with [ 3 H]-thymidine uptake. The CFSE-based assays are equivalent to traditional measures of mitogenand antigen-specific T cell responsiveness in the diagnostic laboratory and have significant advantages in terms of decreased labour intensiveness, avoidance of radioactivity, the ability to gate on a specific population of lymphocytes and the concomitant measurement of activation markers.

Significant numbers of older Chinese migrants appear to be depressed or at risk for depression and, while participants with depressive symptoms consulted general practitioners more than their counterparts without such symptoms, they reported greater difficulty in accessing health services. The findings point to the need for further epidemiological study of this growing sector of the population and investigation of the nature of its engagement with health services. Social support and aspects of acculturation may play a significant role in preventing depression. This also requires further investigation.

SummaryCommon variable immunodeficiency (CVID) is a B cell immunodeficiency disorder characterized frequently by failure of memory B cell development and antibody secretion. A unifying cellular pathogenesis for CVID has not been forthcoming, but given the immunoregulatory role of invariant NK (iNK) T cells and their absence in several other immunodeficiencies, we quantified these cells in the blood of 58 CVID patients. There was a marked decrease in the proportion of iNK T cells in CVID patients compared with controls. This was particularly notable in those with low isotype-switched memory B cells, but subset analysis demonstrated no difference when stratified by specific clinical features. We propose that the decreased proportion of iNK T cells in CVID might be linked to the failure of memory B cell generation, which may contribute to reduced antibody production in these patients.