Popliteal lymph node assay as a method of investigating H-Y antigen in the rat.

The ability of the popliteal lymph node assay (PLNA) To detect host-versus-graft activity in response to H-Y antigens was investigated in the rat by using presensitized recipients. It was shown that significant popliteal lymph node (PLN) enlargement in response to H-Y-incompatible lymphocytes from syngeneic donors could be obtained in female recipients that had been preimmunized by the weekly i.p. injection of 1 x 10(7) lymphocytes from males of the same strain. In one rat strain, it was also shown that when male recipients had been similarly preimmunized with lymphocytes from females of the same strain, significant PLN enlargement could be obtained in response to lymphocytes from syngeneic females. The results that we obtained using the PLNA are discussed in comparison with those that have been reported when H-Y-incompatible skin grafts have been used to investigate H-Y antigen in the rat. These results indicate that, in the rat, the PLNA provides a useful alternative method for the investigation of H-Y antigen and may also provide a useful means to investigate the response of male rats to lymphocytes from syngeneic females.

Evidence of Chlamydia trachomatis infection in sexually acquired reactive arthritis.

Thirty male patients with sexually acquired reactive arthritis (SARA) have been studied at the time of their initial presentation and thereafter. Chlamydia trachomatis was isolated from the urethral exudate of 9 (36.0%) of the 25 patients from whom urethral specimens were taken, and elevated titres of IgM antibody of C. trachomatis were detected in 11 (36.6%) of the 30 initial sera. Thirteen (43.3%) of the patients has a positive urethral culture and/or elevated titre of IgM antibody, and it is therefore suggested that 43.3% of these patients suffered an acute chlamydial infection at or near the time of the onset of their joint disease. The demonstration of 4-fold or greater rises and/or falls in IgM antibody titre (8 patients) and IgG antibody titre (6 patients) in a group of 15 men studied throughout the course of their disease strongly supports this conclusion. A positive urethral culture and/or raised titre of IgM serum antibody was also detected in 25 (50%) of 50 men with uncomplicated nongonococcal urethritis (NGU), suggesting that the prevalence of chlamydial infections in the 2 conditions is similar. Titres of IgG serum antibody to C. trachomatis were, however, significantly higher in patients with SARA than in those with NGU or other rheumatic diseases, and in healthy controls. The geometric mean titres (GMT) of IgG serum antibody in patients with SARA, NGU, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, and in healthy controls were 1:47.5, 1:8.6, 1:2.2, 1;2.2, 1:3.5, and 1:1.4, respectively. These findings suggest that an exaggerated antibody response to acute infection by C. trachomatis may be an important factor in the development of SARA in some but not all patients.

Timing of cyclosporin-A therapy for abrogation of HVG and GVH responses in rats.

Treatment with cyclosporin A was most effective in abrogating popliteal-lymph-node enlargement induced by host-versus-graft and graft-versus-host reactivity in rats when started before injection of donor-strain lymphocytes. Popliteal lymph-node enlargement was never completely abolished, and splenic lymphocytes from recipients treated with cyclosporin A showed no significant reduction in their response to donor-strain lymphocytes in mixed lymphocyte cultures, suggesting that clonal deletion had not taken place. Mixed lymphocyte cultures also indicated that cyclosporin treatment had not reduced the antigenicity of recipient lymphocytes towards donor strain.

The clinical features and HLA associations of reactive arthritis associated with non-gonococcal urethritis.

Fifty-seven patients with arthritis associated with non-gonococcal genital infection have been studied. Synovitis characteristically affected one or a few joints, expecially the knee, ankle or metatarsophalangeal joints and was accompanied by tenosynovitis and enthesopathies--each in about one third of the patients. A quarter of the patients had ocular, cutaneous, or mucous membrane lesions (Reiter's syndrome). Although six patients developed a chronic or relapsing course, average duration of the acute episode in the majority was three to five months. Available evidence strongly suggests that infection following sexual intercourse, usually but not always with a new partner, was instrumental in the initiation of the disease. We have suggested the term 'sexually acquired reactive arthritis (SARA)' to emphasize the mode of acquisition of the disease, and note that similar syndromes are seen associated with gut infection. We consider that usage of the term Reiter's syndrome is correctly applied to only those cases which exhibited the characteristic triad of urethritis, arthritis and conjunctivitis with or without other cutaneous and mucous membrane lesions. Thirty-six of the 54 patients who were HLA typed (67 per cent) possessed the antigen HLA-B27. Of 30 who presented directly to a rheumatology unit 25 (82 per cent) were HLA-B27 positive. The other 24 patients initially attended a venereology clinic and only 11 (46 per cent) of these bore the antigen. This appears to reflect disease severity, HLA-B27 positive patients having a significantly longer duration of disease symptoms and a higher frequency of extra-articular manifestations, than those lacking this antigen.

Anti-lymphocyte antibody levels in chronic lymphocytic leukaemia.

A radioimmunoassay for measuring levels of lymphocyte autoantibody in chronic lymphocytic leukaemia (CLL) has been developed. Antibody in the form of crude IgG was extracted from patients' sera and iodinated. The assay utilizes its cross-reactivity with other CLL cells. Levels were measured in 23 patients. The results show that an inverse relationship exists between the quantity of circulating CLL autoantibodies and the number of mouse red blood cell rosetting lymphocytes (M cells). The preliminary findings do not correlate with disease activity although it is our impression that patients who are maintaining higher levels of autoantibody and fewer M-rosetting cells have nonprogressive disease.

Three additional malignancies occurring within one year in a patient with chronic lymphatic leukaemia.

A patient with crhonic lymphatic leukaemia (CLL) is presented who was first seen with a basal cell carcinoma and subsequently developed two further malignant conditions within a year, without receiving any treatment for his leukaemia. It is suggested that this leukaemia was a predisposing factor in the development of his carcinomas.

Immune complexes in myelofibrosis: a possible guide to management.

Using a fluorescent technique intracellular immune complexes were found in the peripheral leucocytes in all of 12 patients with myelofibrosis studied. Fluorescent cells varied from 12% to 81%; with no relation to the total white count or any obvious clinical finding. Three of the patients with severe refractory anaemia benefited from immunosuppressive therapy.

Role of Chlamydia trachomatis and HLA-B27 in sexually acquired reactive arthritis.

Inflammatory arthritis, tendinitis, and fasciitis after non-specific urethritis ("sexually acquired reactive arthritis" (SARA)) was studied prospectively in 531 men with non-specific urethritis, with particular reference to the frequency of isolation of Chlamydia trachomatis and the presence of HLA-B27. Satisfactory cultures were obtained from the urethral swabs from 384 patients; and HLA typing was performed on 482, of whom 30 (6%) were HLA-B27-positive. Arthritis developed in 16 patients, and five of the 14 (36%) with satisfactory cultures were positive for C trachomatis; 135 of the patients without arthritis were also positive for C trachomatis, an identical proportion. Seven of the 15 patients (40%) with arthritis who were HLA-typed were HLA-B27-positive. Six of the 30 patients with HLA-B27 developed peripheral arthritis in contrast to only nine of the 452 patients lacking the antigen, suggesting a tenfold increase susceptibility. C trachomatis, however, was no more prevalent in cultures from HLA-B27-positive men than from the others. Thus carriage of C trachomatis is unlikely to be influenced by HLA-B27. C trachomatis may be an important pathogen in some cases of SARA but does not appear to be an exclusive trigger factor for this condition.

Significance of mouse red cell rosette-forming lymphocytes in chronic lymphocytic leukaemia.

Increased mouse red cell (M) rosetting lymphocytes were demonstrated in the peripheral blood of patients with chronic lymphatic leukaemia. The range was wide, and patients showed considerable variation not only in the number of M cells but also in T and B rosetting lymphocytes. Treatment reduced M rosette lymphocytes proportionately as the total white count fell, and differential removal occurred only when the patients became leucopaenic. If we assume the M rosetting cells are the abnormal 'leukaemic' cells, treatment does not preferentially remove these. The M rosetting capacity appeared to be related to the presence of an immunoglobulin factor previously demonstrated on the cells and in the serum of patients with CLL which enhances in vitro viability of the leukaemic cells.

Erythrophagocytosis by acute lymphoblastic leukaemic cells.

Phagocytosis of erthyrocytes and platelets by bone marrow blast cells has been noted in 4 patients in the late relapse of acute lymphoblastic leukaemia (ALL). The underlying mechanism is unclear but prolonged course of the disease seems to be a major factor in the emergence of cells with phagocytic properties.

Autoimmune antibodies in chronic lymphatic leukaemia.

In chronic lymphocytic leukaemia a factor in patients' serum enhances the in vitro viability of the abnormal cells and this has been identified as an antibody. The activity of this factor can be removed by interaction with anti-immunoglobulin and by ammonium sulphate precipitation with a degree of saturation in excess of 46%. Cohn fractionation and chromatography with A-50 Sephadex show that the factor is not a complex but an immunoglobulin. No activity is removed after reaction of sera with 2-mercapto-ethanol and di-thiothreitol. The evidence therefore suggests that a gamma-G immunoglobulin is involved. Concentrated washings from the leukaemic cells behave in exactly the same way as patients' sera and activity is retained in the same fraction during precipitation and purification procedure. The extensive cross-reactivity of the sera suggests a common chronic lymphatic leukaemic antibody and it is considered that an active autoimmune response may be an integral part of the disease.

Immune complexes in myeloproliferative disorders.

A fluorescein-labelled anti-human immunoglobulin was used to demonstrate that peripheral blood from patients with myelofibrosis had a high proportion of phagocytic cells containing fluorescent immune complexes. Cells from patients with other myeloproliferative diseases (either chronic myeloid leukaemia or polycythaemia rubra vera) did not show similar intracellular immune complexes. Serum from patients with myelofibrosis incubated with polymorphs from healthy subjects caused the appearance of inclusions similar to those found when the patients' own cells were used, the healthy phagocytes apparently engulfing complexes from the patients' sera. The presence of platelets or complement did not alter the incidence of intracellular fluorescence. These tests may help in the diagnosis of myelofibrosis and may also be valuable in recognising the onset of this condition in patients with polycythaemia rubra vera.