Spinal entheseal new bone formation: the early changes of spinal diffuse idiopathic skeletal hyperostosis

Diffuse idiopathic skeletal hyperostosis is characterized by new bone growth at the point of insertion of ligaments and tendons to bone. We examined retrospectively the anatomical morphologic changes discernible at the insertion of spinal longitudinal ligamentous fibrous tissue to vertebral bodies. The earliest evidence of bone formation was in the "waist" of the vertebral body away from the intervertebral disc area. New bone arose along the insertion of the fibrous tissue to the anterior cortical surface of the vertebral body and progressed along the fibres at an angle to the cortical surface distinct from it until the advanced stages. With disc degeneration the 2 processes were distinct and separate. Degenerative disc disease occurred at the margin of the endplate of the vertebral body with associated changes in the disc itself. Entheseal ossification occurred remote from the margin of the intervertebral disc and remained distinct from the subjacent vertebral body as it followed the ligamentous tissue; fusion with the cortical surface of the subjacent vertebral body was only seen in the most advanced cases of disseminated idiopathic systemic hyperostosis.

Shrinking lung syndrome in SLE--a clinical pathologic study

A patient with systemic lupus erythematosus (SLE) who developed shrinking lung syndrome during the course of her disease is described. Postmortem findings of diffuse diaphragmatic fibrosis support the hypothesis of an extrapulmonary restrictive etiology in this unusual condition.

The significance of thrombocytopenia in systemic lupus erythematosus

The significance of thrombocytopenia in systemic lupus erythematosus (SLE) is unclear. Some researchers have found it associated with severe disease, others with mild disease. Thrombocytopenia (platelets less than 100,000) occurred in 21 patients seen at an SLE clinic over 18 months. Prospective assessment of 19 (non-SLE causes excluded) revealed 2 distinct subgroups. Seven were thrombocytopenic only during severe multisystem flares. Twelve had chronic thrombocytopenia with intermittent mild flares in other systems. Serious bleeding was rare in both subgroups. It was concluded that thrombocytopenia clearly is not a prognostic indicator.

Systemic lupus erythematosus in males

A study of 51 males being followed in the Wellesley Hospital Toronto SLE Clinic examined the questions of whether SLE in males was similar to that in females and whether affected males differ from unaffected males with respect to their maleness and sex hormone profile. Fifty of the men were phenotypically males, and one was known to have Klinefelter syndrome (karyotype 47 XXY). All had four or more 1982 revised criteria for SLE. Fifty females matched with respect to age and duration of disease were used as controls. In examining the spectrum of the disease, 21 clinical and laboratory manifestations were assessed. Although neurologic involvement, alopecia, and thrombocytopenia were less common and pleuritis more common in the males, none of these was statistically significant. Comparison of disease severity revealed only one statistically significant difference: the mean duration of corticosteroid usage was longer in the females. There was also a tendency for cytotoxic agents to be used more frequently in the females. It was thus concluded that spectrum and severity of the disease tended to be similar in males and females. The frequency of positive family histories for SLE and other autoimmune diseases was similar in males and females. The age of onset tended to be more evenly distributed in males than in females, with one quarter of the males diagnosed after the age of 50. HLA typing revealed increased frequencies of the B8 and DR3 antigens in the SLE males compared with normal controls, as had previously also been shown for SLE populations with a female preponderance.(ABSTRACT TRUNCATED AT 250 WORDS)

Systemic lupus erythematosus and diffuse soft tissue calcifications

A 26-year-old white woman developed systemic lupus erythematosus (SLE) and extensive soft tissue calcification. Striking features of this patient related to severe complication of corticosteroids, including proximal muscle weakness and multiple areas of avascular necrosis. In addition to localized areas of erythematosus induration, the patient demonstrated yellowish papules on her legs. Biopsies of the former showed thickening of the dermis with extensive collagen deposition and focal deposits of calcium. The latter revealed eosinophilic degeneration of the subcutaneous fat.

Effect on the human complement system of the major non-steroidal anti-inflammatory drugs: aspirin, indomethacin, phenylbutazone, oxyphenbutazone and sulindac

The possibility that the major non-steroidal anti-inflammatory drugs may inhibit the complement system and thus ameliorate the acute pathological changes induced by immune complexes was investigated. Treatment of fresh human serum with indomethacin (IDM), sulindac (Su), phenylbutazone (Ph) and oxyphenbutazone (OPh) inhibited both the classical and alternative complement (C) pathway activities in a dose-dependent fashion with a 50% inhibition dose of 4.65, 1.0, 1.65 and 1.3 mg/ml respectively. Aspirin, on the other hand, had a comparatively weak anti-complementary activity. Su, Ph and OPh were shown to form complexes with C5, thereby inhibiting the interaction between C3b and C5 and the cleavage of the latter into phlogistic fragments.

67Gallium lung scans in progressive systemic sclerosis

67Gallium lung scans were performed in 19 patients with progressive systemic sclerosis (scleroderma). Results were expressed quantitatively as the 67Gallium Uptake Index. The mean total pulmonary 67Gallium Uptake Index in patients was significantly higher than that in controls (41 versus 25), and 4 patients (21%) fell outside the normal range. There were no clinical or laboratory variables that correlated with the 56gallium uptake. Increased pulmonary 67gallium uptake in scleroderma may prove useful as an index of pulmonary disease activity.

Cranial computerized tomography in systemic lupus erythematosus

Twelve patients with active central nervous system systemic lupus erythematosus (CNS SLE) and 11 patients without CNS involvement, all taking corticosteroids, were studied by computerized tomography (CT). Thirty CT scans on 23 individuals were performed and read blindly and independently by 2 neuroradiologists with an 86% correlation. Minimal to moderate atrophy was the most frequent finding, both in CNS SLE and controls, severe atrophy seen in 1 patient only, and no atrophy in 3 patients and a single control. Of the 6 patients who had repeated scans, 4 showed no change in the degree of atrophy, 1 had more and 1 less atrophy. Three patients had evidence of multiple brain infarcts on scan with or without associated cerebral atrophy. Sequential scans in 1 of these patients showed total resolution of the infarcts after 30 months. Thus, there was no correlation between the presence of cerebral atrophy on CT scan and CNS SLE. Rather our findings suggest that steroids may be the cause of atrophy.

Long-term outcome in Felty's syndrome

Felty's syndrome has again been shown to be a severe form of systemic rheumatoid disease characterised by severe joint involvement, many extra-articular features, and a high incidence of infection. In addition we have shown that splenectomy was not protective for infections and in fact may on occasion contributed to infection. Furthermore, although most patients had an increase in white blood cell count after splenectomy, 50% of patients without splenectomy showed a similar increase in white blood cell counts at follow-up. Mortality in Felty's syndrome was high, with infection being the main cause of death.

Liver disease in Felty's syndrome

Eighteen patients with Felty's syndrome were examined prospectively for the presence of hepatic abnormalities. Twelve patients had abnormal liver histologic features: five with nodular regenerative hyperplasia and seven with portal fibrosis or abnormal lobular architecture. Only seven of the 12 had abnormal liver chemistry results. Four of the 12 had portal hypertension, and three bled from esophageal varices compared with one of six with normal histologic features. When patients with normal and abnormal liver histologic findings were compared, there was no difference in clinical, serologic, or extra-articular manifestations between the two groups, although there was a tendency for the patients with abnormal findings to have a higher incidence of vasculopathy. All patients with Felty's syndrome should be screened for hepatic abnormalities and portal hypertension as they have an increased likelihood of bleeding from esophageal varices.

Peripheral enthesopathy in diffuse idiopathic skeletal hyperostosis (DISH): a radiologic study

Radiographs of selected peripheral entheseal regions from 32 patients with axial diffuse idiopathic skeletal hyperostosis (DISH) were examined for the presence of new bone formation. The prevalence of entheseal new bone in the various regions was as follows: 98% of tibial spines, 91% of posterior heel regions and about 80% of superior patella, olecranon and inferior heel regions. The new bone showed characteristic solid well defined cortical margins without features of inflammatory change. We suggest that further attention to these readily accessible and easily interpretable peripheral entheseal regions, particularly the posterior heel, may be useful to extend the diagnostic criteria of DISH.

Prolonged complete remission in previously severe SLE

Of 160 patients with systemic lupus erythematosus followed up in a long-term prospective study 4 with previously severe disease are in complete remission and have required no therapy for a median time of 75 months. The 4 females all presented with systemic features and a typical butterfly rash prompting early diagnosis and treatment. All patients have had complete remission of clinical and laboratory features of disease, without maintenance suppressive therapy.

Long-term effects of azathioprine in rheumatoid arthritis

Efficacy and safety of azathioprine in 'high' and 'low' dose regimens in rheumatoid arthritis (RA), both in short-term studies and in follow-up over 40 months, have previously been shown. In the present report, 36 patients with RA treated with azathioprine (group I) and 49 age-matched patients with RA (group II), were studied to detect potential early markers of malignancy. Chest x-rays were similar to both groups. One patient in group I had a positive PAP smear and was subsequently found to have uterine carcinoma. Alpha-fetoprotein was positive in one patient in group I and none in group II. CEA was negative in all patients in group I, but positive in seven in group II. On chromosomal analysis group I showed a greater frequency of breakage. Group I showed lower serum folates and a highly significant number of megaloblastic features in marrow aspirates. In group I seven tumours, three being malignant, occurred while taking azathioprine, and in group II six tumours, one malignant, were identified (p = 0.17). The apparent increased risk of malignancy previously suggested by others warrants further studies with larger populations and over a continuous longer period.

Radiographic features of the hand in diffuse idiopathic skeletal hyperostosis (DISH): comparison with normal subjects and acromegalic patients

Radiographs of the hands of 25 men and 9 women with diffuse idiopathic skeletal hyperostosis (DISH) were compared with age- and sex-matched controls and acromegalic patients. Characteristics of DISH included broadening and "arrowheading" of the distal phalangeal tufts, enlarged sesamoid bones, increased cortical width of tubular bones, prominent enthesopathy in the proximal phalanges, exostoses (particularly at the metacarpophalangeal heads), and new bone in the joint capsule. There was no consistent change in soft-tissue measurements or cartilage width between DISH and control patients. Acromegaly could be differentiated from DISH by the relative lack of enthesopathy, marked soft-tissue changes, and increased cartilage width. Any metabolic factor responsible for the changes in DISH apparently acts primarily on the enthesis and bone but has little effect on soft-tissue or cartilage growth.

Systemic lupus erythematosus in a patient with C4 deficiency

A 40-year-old female with systemic lupus erythematosus was found to be totally deficient in the 4th component of complement and to be lacking in Chido and Rodgers blood group substances on red cells and in plasma. Family studies were suggestive of a linkage of the C4 deficiency with an HLA haplotype. C2 in the patient's serum was 50% of normal but other complement components and alternative pathway functions were normal. Chemotactic and opsonic activities in the patient's serum were diminished.

Selective deficiency of the fourth component of complement in a patient with systemic lupus erythematosus (SLE): immunochemical and biological studies

A 45-year-old female (J.B.) with clinically inactive systemic lupus erythematosus was devoid of haemolytic serum complement activity. Functional and immunoprecipitin assays showed that the complement defect was due to lack of the fourth component of complement (C4). The patient's serum and red cells were Chido-negative, Rodgers-negative. In J.B.'s serum there was marked impairment of opsonization of Staphylococcus aureus and of the formation of chemotactic activity in the presence of zymosan. The chemotactic defect was not due to the presence of inhibitory factors: the activity was increased by the addition of C4. These findings suggest that an intact classical pathway is necessary for the optimal generation of serum chemotactic factors by zymosan via the alternative pathway of the complement system.

Central retinal vein occlusion and scleroderma: implications for sclerodermatous vascular disease

A patient with scleroderma (progressive systemic sclerosis) who developed central retinal vein occlusion is described. The aetiology of this condition is discussed and the role of possible sclerodermatous vascular disease is highlighted. It is suggested that studies of fundal vasculature could be useful in the clinical assessment of sclerodermatous vascular disease.

Systemic lupus erythematosus and pregnancy

In a review of 250 patients with systemic lupus erythematosus (SLE), there were 24 pregnancies among 18 women. Of these, there were 16 completed pregnancies, 1 stillbirth, 1 spontaneous abortion, and 6 therapeutic abortions. Fetal loss, excluding therapeutic abortion, was 16.6%. Of the 13 patients with active disease at conception, SLE remained active in 11, and became inactive in 2. Of the 11 women with inactive disease at conception, disease remained inactive in 10. Even in the cases of previously serious renal or central nervous system involvement, inactive disease at conception was not associated with disease recurrence. Such patients may attempt pregnancy with favorable prognosis for both mother and child.

Venous syndromes and pulmonary embolism in systemic lupus erythematosus

Deep vein thrombophlebitis (DVT) and pulmonary emboli (PE) have been uncommonly reported manifestations of systemic lupus erythematosus (SLE). This may be partly due to their being masked by other more familiar lesions of the lungs and extremities in SLE. We have identified 17 patients with SLE from a population of 180 being followed up prospectively who had 21 attacks of DVT and/or PE. Of the total of 21 episodes the SLE was considered to be active in 14, inactive in 6, and variable in a patient with recurring phlebitis. The incidence of hyperlipidaemia, smoking history, and use of birth control medication or corticosteroids was not higher in these patients. These clinical findings thus constitute additional features of SLE occurring in about 9% of patients and may be significance for morbidity and mortality.

Neuropsychiatric lupus

Sixty-six systemic lupus erythematosus (SLE) patients followed prospectively had 77 episodes of neuropsychiatric lupus (NPL). Patients with NPL had more SLE manifestations than patients without NPL. Serologic data and cerebrospinal fluid analysis were not helpful in identifying an episode of NPL. Electroencephalogram was abnormal in more than 1/2 and brain scans in more than 3/4 of patients. In 74 episodes with a known outcome, 54 improved, 44 having been treated with increased corticosteroids. Patients with NPL had a higher incidence of deaths compared to patients without NPL.

Cytotoxic activity of cerebrospinal fluids (CSF's) against lymphocytes and phagocytes: comparison of normal and systemic lupus erythematosus CSF's

Fifty cerebrospinal fluids (CSF), 24 normal, 26 from systemic lupus erythematosus (SLE) patients were tested for cytotoxic activity against human lymphocytes, granulocytes and monocytes. Normal and SLE CSF's frequently killed all 3 cell types. Lympho- and granulocytotoxins often reacted at both 4 degrees/24 degrees C, and at 37 degrees C. They were more active when no complement was added (p less than 0.01), whereas monocytotoxicity was complement-dependent (p less than 0.01). Normal CSF's more often contained cold-reacting lymphocytotoxins and SLE CSF's more often had warm-reacting monocytotoxins, but the differences were not significant (p = 0.03). Cytotoxins were easily absorbed to and eluted from lymphocytes and granulocytes, and when CSF's were toxic to both types of cells, the corresponding eluates usually retained this activity. Sometimes, only 1 type of cell was killed by the eluate, whereas cytotoxicity against another was retained by the corresponding supernatant. In SLE remarkable differences were noted between CSF cytotoxins and serum cytotoxins. The former were often more potent at 37 degrees C not requiring non-human complement. Preliminary characterization of CSF cytotoxins suggests they may be IgG, however, participation of non-Ig cytotoxic substances cannot be excluded.

The immune response and the connective tissue diseases

Immunological aberrations are recognizable in a number of the connective diseases such as SLE and RA. Some of these abnormalities are reviewed, in particular the variety of circulating auto-antibodies and their possible relationship to disease, as well as some evidence for involvement of circulating immune complexes. A number of these abnormalities have become the basis for essential tests in the diagnosis and management of these disorders and helping monitor their response to therapy.

Leucapheresis in severe rheumatoid arthritis

Two patients with severe seropositive rheumatoid arthritis previously unresponsive to conventional therapy have been treated with leucapheresis. This technique involves continuous cell separation daily to remove primarily lymphocytes. Clinical improvement was recorded with the use of standard rheumatological measures of inflammation. It is concluded that leucapheresis may help in the management of severely active rheumatoid arthritis when conventional therapy has been unsuccessful.

Serologically active clinically quiescent systemic lupus erythematosus: a discordance between clinical and serologic features

The significance of abnormal serologic tests in systemic lupus erythematosus (SLE) in the absence of active clinical disease is unclear. In this report we describe a group of 14 patients with SLE in whom a discordance between clinical and serologic features was apparent. These patients had persistently positive lupus erythematosus preparations and antinuclear antibody tests, low serum complement levels and high levels of DNA binding. Their lymphocyte response to concanavalin A (Con A) mitogen was suppressed. They have been asymptomatic and have remained untreated for a mean of four and a quarter years.

Brain scan diagnosis of central nervous system involvement in systemic lupus erythematosus

Twenty-five patients with 29 episodes of active systemic lupus erythematosus with central nervous system involvement were studied according to a uniform protocol. Brain scans were found to be abnormal in all patients studied, and electroencephalograms were abnormal in 20/25 patients. Serial brain scanning was found to be useful in the diagnosis of exacerbations and the monitoring of corticosteroid dosage.

Postdiarrheal arthropathy of Yersinia pseudotuberculosis

Two patients with acute gastroenteritis in whom polyarthritis subsequently developed were found to have positive serologic results for Yersinia pseudotuberculosis. With resolution of the arthropathy the antibody titres decreased. While the patient without the histocompatibility antigen HLA-B27 had an acute, self-limited arthritis, the patient with this antigen had a more chronic arthritis. Serologic typing and stool culture for Y. pseudotuberculosis should be done in cases of postdysenteric arthritis.

Comparison of osteitis condensans ilii and ankylosing spondylitis in female patients: clinical, radiological and HLA typing characteristics

A study comparing 12 patients with ankylosing spondylitis (AS) to 25 with osteitis condensans ilii (OCI), referred to a rheumatic disease center, was carried out to determine whether OCI represents a varient of AS in women. In the group with OCI, chronic lumbodorsal pain was present in 9, 36%, a 'fibrositis' syndrome in 6, 24%, and 16, 64% had recurrent episodes of polyarthralgia. A definite arthritis with effusion developed in 10 patients, 40%. No patient with OCI had iritis or colitis, whereas 4 patients with AS had iritis and four had colitis. Radiographs of the spine showed no evidence of spondylitis in the OCI group. Of the 25 patients with OCI, only 2, 8% were HLA B27 positive compared with 11 of 12 patients with AS, 92%. These results suggest that OCI is not a variant of AS in women.

Felty's syndrome. Clinical and serological analysis of 34 cases

Review of 34 cases of Felty's syndrome showed this to be a form of 'super' rheumatoid disease because of the severity of joint disease, the prominence of extra-articular features and the remarkable incidence of infection. The response to splenectomy in these 34 patients was shown by a return towards normal of peripheral blood abnormalities and a decrease in bone marrow granulopoiesis. Although some patients remained free of infection after splenectomy, others have continued to have infections despite the return of white blood cell counts to normal levels. Although splenectomy and subsequent increase in white blood cell levels may be beneficial, our experience suggests that other factors are important in the susceptibility to infection of Felty's syndrome patients. Moreover, we think that splenectomy may have been instrumental in the fatal infection of one of our patients.

HLA B27 in rheumatoid factor-negative polyarthritis

Eighty-three consecutive patients with rheumatoid factor-negative polyarthritis seen during a 1-year period were evaluated clinically, radiologically, and with the B27 test. Patients with definite spondylitis, juvenile chronic polyarthritis, a collagen disease, a known metabolic arthropathy, or primary generalized osteoarthritis were excluded. The patients could be classified into two groups independent of any knowledge of B27 testing. Twenty-five had a spondylitic "variant" syndrome. These could be diagnosed on clinical grounds, and included a male preponderance and a high frequency of B27 positivity. Fifty-eight patients, who could generally be classified by American Rheumatism Association criteria as having definite or classic rheumatoid arthritis, included a female preponderance and a normal prevalence of B27. Thus the B27 test was not more helpful than clinical diagnosis in the classic spondylitic variant syndromes, nor did it separate out a population of patients from among the seronegative rheumatoid arthritis group.

Azathioprine in early rheumatoid arthritis. Comparison with gold and chloroquine

This study compares the effect of azathioprine with those of gold and chloroquine in early (Class II) rheumatoid arthritis (RA). Thirty-three similar patients with classic or definite RA of less than 5 years duration were randomly entered, 11 into each drug group. Assessment of standard clinical and laboratory measures at 12 and 24 weeks showed significant improvement in all three groups. In general, all three drugs were effective antirheumatic agents with low toxicity. However, because of serious potential toxicity, azathioprine could not be recommended over gold and chloroquine in early RA therapy.

Systemic lupus erythematosus. A review of 110 cases with reference to nephritis, the nervous system, infections, aseptic necrosis and prognosis

Observations made on 110 patients with SLE over a four and a half year period have been reviewed. The patients were seen at intervals of two months when, both clinical and serological findings were recorded, according to a set protocol. The results have been presented with particular reference to nephritis, neurological manifestations, infections, aseptic necrosis, mortality and predicted survival. Such studies have led to the identification of various prognosis factors in SLE, and assisted in providing better directed therapy. The results indicate a milder from of SLE in the patients of this series when compared with previously published studies, and is more representative of the wide spectrum of disease severity seen in the general population.

Acute leukemia in rheumatoid arthritis treated with cytotoxic agents

Acute leukemia is described in two patients treated with cytotoxic agents for a destructive, seropositive rheumatoid arthritis. Both patients had received longterm azathioprine therapy. In addition, one patient had been treated with cyclophosphamide, the other with melphalan. Chromosomal abnormalities were noted in both patients. Studies in one patient included colony forming units, ferrokinetics, electron microscopy of bone marrow, and autopsy examination. All reports of acute leukemia associated with cytostatic drugs in the literature to date are reviewed and the possible mechanisms discussed. It is suggested that patients with rheumatoid arthritis treated with azathioprine and alkylating agents may have an increased risk of developing a therapy-related acute leukemia.

Pericardial fluid analysis in scleroderma (systemic sclerosis)

A patient with scleroderma who presented with pericarditis and effusion is described. Aspirates from this pericardial effusion had the characteristics of an exudate with no evidence of autoantibodies, immune complexes or complement depletion. These findings suggest that the mechanisms operating in the production of pericardial effusion in scleroderma may be different from those found in rheumatoid arthritis and systemic lupus erythematosus.

Mixed leukocyte reaction in rheumatoid arthritis

The mixed leukocyte reaction (MLR) responses of 29 patients with classic rheumatoid arthritis (RA) were compared with those of 24 age- and sex-matched healthy controls. Pools of stimulating cells were selected to include the major cross-reacting HL-A specificities. In pooled human serum the MLR response of the RA lymphocytes was significantly enhanced relative to the response controls (P less than 0.05). In autologous serum there was suppression of the MLR response in patients with RA which correlated with disease activity. The data suggest the presence of an intrinsically enhanced cellular reactivity of RA lymphocytes suppressed by serologic factor(s). The mechanisms of this enhancement of suppression are discussed.

Gold-induced enterocolitis. Case report and literature review

A case of gold-induced enterocolitis and a review of the literature are reported. Gold-induced enterocolitis appears to be an uncommon reaction, occurring in middle-aged females who have received low doses of gold preparations. Symptoms may include fever, nausea, vomiting, abdominal cramps, and diarrhea with or without blood. The whole of the gastrointestinal tract may be involved and fatal cases occur. The diagnosis of a primary enteropathic arthropathy may be suggested. Cessation of gold, glucocorticoids and supportive therapy are indicated. The mechanism of the reaction is still unknown.

The bimodal mortality pattern of systemic lupus erythematosus

The changing pattern of mortality in systemic lupus erythematosus (SLE) led to an examination of the deaths in a long-term systematic analysis of 81 patients followed for five years at the University of Toronto Rheumatic Disease Unit. During the follow-up 11 patients died; six patients died within the first year after diagnosis (group I) and five patients died an average of 8.6 years (from 2.5 to 19.5 years) after diagnosis (group II). In those who died early, the SLE was active clinically and serologically, and nephritis was present in four. Their mean prednisone dose was 53.3 mg/day. In four patients a major septic episode contributed to their death. In those who died late in the course of the disease, only one patient had active lupus and none had active lupus nephritis. Their mean prednisone dose was 10.1 mg/day taken for a mean of 7.2 years. In none was sepsis a contributing factor to their death. All five of these patients had had a recent myocardial infarction at the time of death; in four, ti was the primary cause of death. Mortality in SLE follows a bimodal pattern. Patients who die early in the course of their disease, die with active lupus, receive large doses of steroids and have a remarkable incidence of infection. In those who die late in the course of the disease, death is associated with inactive lupus, long duration of steroid therapy and a striking incidence of myocardial infarction due to atherosclerotic heart disease.

Azathioprine in rheumatoid arthritis: a long-term follow-up study

In 1973 we reported the beneficial effects of azathioprine in a double blind, cross-over study in 17 patients with classic rheumatoid arthritis. During subsequent follow-up over a mean period of 40 months, 4 patients had discontinued therapy because of poor therapeutic response and 1 because of nausea. Eleven of the 12 patients still taking azathioprine had maintained their initial beneficial response or showed further improvement. Adverse side effects during the follow-up period were minor. They included nausea in 1 patient and leukopenia with thrombocytopenia in another. An increased incidence of chromosomal abnormalities was detected in those patients still receiving azathioprine.