A comparative study of two methods for treatment of benign paroxysmal positional vertigo in the emergency department

Introduction

Posterior canal benign paroxysmal positional vertigo (PC-BPPV) is considered the most common cause of peripheral vertigo in the emergency department (ED). Although the canalith repositioning maneuver (CRM) is the standard of care, the most effective method to deliver it in the ED has been poorly studied.

Objective

To compare two protocols of the Epley maneuver for the treatment of PC-BPPV.

Patients and methods

We prospectively recruited 101 patients with unilateral PC-BPPV on physical examination, randomizing them to either a single Epley maneuver (EM) (n = 46) or multiple maneuvers (n = 55) on the same visit. Measured outcomes included presence/absence of positional nystagmus, resolution of vertigo, and score on the dizziness handicap inventory (DHI) at follow-up evaluations. The DHI was stratified into mild (≤30) and moderate-severe (>30).

Results

Normalization of the Dix-Hallpike maneuver at day 5 was observed in 38% of the single EM group and 44.4% in the multiple EM group (p = 0.62). The DHI showed reduction from 42.2 (SD 18.4) to 31.9 (SD 23.7) in the single EM group and from 43.7 (SD 22.9) to 33.5 (SD 21.5) in the multiple EM group (p = 0.06). A higher number of patients improved from moderate-severe to mild DHI (p = 0.03) in the single EM group compared to the multi-EM group (p = 0.23).

Conclusion

There was no statistically significant difference between performing a single EM versus multiple EMs for treatment of PC-BPPV in the emergency department. The single EM approach is associated with shorter physical contact between patients and examiner, which is logically safer in a pandemic context.

Sense of coherence and physical health-related quality of life in Italian chronic patients: the mediating role of the mental component

OBJECTIVE

To examine the relationship between sense of coherence (SOC) and physical health-related quality of life in patients with chronic illnesses by focusing on the mediating role of the mental component of quality of life.

DESIGN

Cross-sectional survey design.

SETTING

Secondary care; three departments of an Italian university hospital.

METHODS

The participants (n=209) in the study were adult (≥18 years) outpatients with a chronic pathology (eg, diabetes, thyroid disorders or cancer) at any phase in the care trajectory (eg, pre-treatment, undergoing treatment, follow-up care). They agreed to participate in the study after providing their informed consent. Data were collected using a structured self-reporting questionnaire. Data analysis was carried out using SPSS, and mediation analysis was performed via PROCESS macro.

RESULTS

The SOC score of the study sample was equivalent to that of the general population (mean difference=-2.50, 95% CI -4.57 to 0.00). Correlation analysis showed that SOC was mainly correlated to the mental component (MCS) (r=0.51, p<0.01) of quality of life and then to the physical component (PCS) (r=0.35, p<0.01). Mediation analysis showed that SOC was directly related to MCS (p<0.001, 95% CI 0.62 to 0.99) but not to PCS (p=0.42, 95% CI -0.27 to 0.12). In turn, MCS was directly related to PCS (p<0.001, 95% CI 0.76 to 1.01). The indirect effect of SOC on PCS through MCS was significant (0.71, p<0.001, bootstrap 95% CI 0.54 to 0.91), thus supporting the mediating role of the mental component of quality of life.

CONCLUSION

The indirect effect suggests that SOC is a marker of quality of life, especially of the mental component. The findings show that SOC is a psychological process that impacts patients' mental health status, which in turn affects physical health. Better knowledge of a person's SOC and how it affects his/her quality of life may help to plan tailoring interventions to strengthen SOC and improve health-related quality of life.

Mal de débarquement syndrome

Mal de débarquement syndrome (MdDS) is typified by a prolonged rocking sensation - for a month or longer - that begins immediately following a lengthy exposure to motion. The provoking motion is usually a sea voyage. About 80% of MdDS sufferers are women, and most of them are middle-aged. MdDS patients are troubled by more migraine headaches than controls. Unlike dizziness caused by vestibular disorders or motion sickness, the symptoms of MdDS usually improve with re-exposure to motion. The long duration of symptoms - a month or more - distinguishes MdDS from land-sickness. Treatment of MdDS with common vestibular suppressants is nearly always ineffective. Benzodiazepines can be helpful, but their usefulness is limited by the potential for addiction. Studies are ongoing regarding treatment with visual habituation and transcranial magnetic stimulation.

Oesophageal motility in adult coeliac disease

Coeliac sprue is a relatively frequent disease with protean clinical manifestations. Recent studies suggest that gastrointestinal motor abnormalities may explain some symptoms complained of by such patients. We investigated whether coeliac patients have oesophageal motor abnormalities from both a clinical and a physiological point of view. Thirty-six consecutive adult sprue subjects (14 during the florid phase and 22 on gluten-free diet) were studied. A clinical questionnaire on gastrointestinal symptoms (with emphasis on those of oesophageal origin) was administered. Moreover, 18 patients (13 on free and five on gluten-free diet) gave their consent for oesophageal manometry and eight subjects for pH-metry also. Oesophageal clinical symptoms were compared with those of 144 age- and sex-matched controls from a general population sample, and manometry with that of 34 healthy volunteers. Of coeliac patients 50% complained of dysphagia (P < 0.001 vs. controls) and 14% noncardiac chest pain (P = NS vs. controls). Manometric examination showed motor abnormalities in 67% of the subjects examined, consisting of nutcracker oesophagus, hypotonic lower oesophageal sphincter associated with simultaneous contractions, and frequent repetitive (> 3 peaks) contractions. These abnormalities were equally distributed among free and gluten-free diet patients. pH-metry showed only one pathological reflux out of eight subjects studied. We conclude that patients with coeliac sprue may display abnormal oesophageal motility. This confirms previous studies suggesting that gastrointestinal motor abnormalities should probably be added to the clinical spectrum of the disease.

Activated and "memory" phenotype of circulating T lymphocytes in intrauterine life

We examined the expression of T cell markers in the peripheral blood of five immunologically normal human fetuses at 18-20 weeks of gestational age. The distribution of T cells expressing CD1, CD3, CD4, CD8, CD56, and the alpha/beta and gamma/delta receptors for antigen was comparable to that of newborns and normal adults, except for the absence of gamma/delta cells expressing the delta TCS-1 epitope. The V beta repertoire, as evaluated by two-color flow cytometry using mAbs to specific V beta families, was also comparable to that of adult samples. A significant fraction (8.9 to 16.4%) of fetal CD3+ T cells expressed the alpha chain of IL-2R (CD25) in the absence of HLA-DR; this suggests that antigenic stimuli trigger, during intrauterine life, an unusual pathway of T cell activation. Consistent with this, 7 to 27% of fetal T cells were found to express the CD45R0 marker of "memory" cells.

Detection and characterization of apoptotic peripheral blood lymphocytes in human immunodeficiency virus infection and cancer chemotherapy by a novel flow immunocytometric method

We have developed a quantitative and sensitive flow cytometric method for the detection of human apoptotic lymphocytes that, unlike previously described assays, allows their identification in mixed populations of peripheral blood leukocytes as well as their immunophenotyping. Apoptotic lymphocytes are identified on the basis of peculiar light scatter changes, reflecting their smaller size and their modified nucleus/cytoplasm organization, and of the decreased expression of surface CD45 molecules. Based on these criteria, apoptotic lymphocytes generated by exposure to ionizing radiation can be easily distinguished from viable cells and from necrotic lymphocytes generated by treatment with antibody and complement. Using this assay, we reappraised the phenomenon of the in vitro apoptosis of lymphocytes from patients with human immunodeficiency virus (HIV) infection. Lymphocytes from HIV patients, unlike those from normal HIV-negative subjects, undergo apoptosis upon simple in vitro culture. We found that the percentages of lymphocytes undergoing apoptosis were significantly higher in patients with low CD4 cell counts (< 400/microL) than in patients at earlier stages (> 400 CD4 cells/microL). However, phenotypic analysis disclosed that apoptotic lymphocytes generated in these cultures were mostly CD8+ T cells and CD19+ B cells. Thus, in contrast to what has been previously suggested, the phenomenon of in vitro lymphocyte apoptosis might not be pathogenetically related to the depletion of CD4+ T cells in acquired immunodeficiency syndrome. Nevertheless, it might represent an useful marker of disease progression. Our assay allows the analysis of unfractionated peripheral blood leukocytes and thus the identification of apoptotic lymphocytes circulating in vivo. Apoptotic lymphocytes could indeed be detected in the circulation of a patient with cancer shortly after high-dose cytotoxic chemotherapy. By contrast, no apoptotic lymphocytes could be detected in vivo in patients with early or advanced HIV infection.

T-lymphocyte reactivity to the recombinant mycobacterial 65- and 70-kDa heat shock proteins in multiple sclerosis

Owing to their conservation and immunogenicity, heat shock proteins (hsps) represent a class of potential autoantigens. Moreover, they could be targets for gamma delta T lymphocytes, which are prominent in various immune disorders. We studied the T cell proliferative primary responses to recombinant M. bovis 65 kDa hsp (hsp65) and M. tuberculosis 70 kDa hsp (hsp70) in 31 patients with multiple sclerosis (MS), 19 patients with other neurological diseases (OND) and 19 healthy individuals. Positive responses to hsp70, but not to hsp65 were significantly more frequent in patients with MS than in patients with OND or in healthy individuals. In order to verify and refine these results and to characterize the hsp reactive T lymphocytes, we screened 147 PPD-specific long-term T cell lines (76 from 10 patients with MS and 71 from 12 healthy donors) for their proliferative response to hsp65 and hsp70. hsp70-reactive T lines were significantly more common in patients with MS than in healthy controls. The number of T lines responding to hsp65 increased in the MS group only slightly. In 19 T lymphocyte lines from patients with MS and healthy donors, a cytofluorometric analysis was performed with special attention paid to distinct T cell receptor gamma delta determinants. With one exception, in each line the population of gamma delta T cells remained a minority. We conclude that an increased T cell response to mycobacterial hsp70 may be present in patients with multiple sclerosis.

Absence of antibodies to human herpesvirus-6 in patients with slowly-progressive human immunodeficiency virus type 1 infection

To evaluate a possible role for Human Herpesvirus-type 6 (HHV-6) coinfection as a co-factor in the progression of HIV-1 disease, we investigated the prevalence of seropositivity for HHV-6 in a cohort of HIV-1 infected patients. These patients were retrospectively divided into two groups according to the decline of CD4+ T cells during the follow up: 11 were classified as rapid decliners (less than 400 CD4+/cmm within 1 year), and 38 as slow decliners (greater than 400 CD4+/cmm after at least 4 years' follow up). HHV-6 antibodies were detected by a commercial immunofluorescence assay and by a Western blotting assay developed in our laboratory. Our results show that Western blot appears to provide results satisfactorily free of false positivities. We found that the frequency of HHV-6 seropositivity was significantly lower in the group of slow decliners, compared both to rapid decliners and to the general population. These data suggest a role for HHV-6 co-infection in the progression of HIV-1 disease.

Relative increase of T cells expressing the gamma/delta rather than the alpha/beta receptor in ataxia-telangiectasia

In ataxia-telangiectasia, B-cell and T-cell deficiencies are thought to be due to a defect of rearrangements of immunoglobulin and T-cell receptor genes. T cells recognize antigens through two types of CD3-associated receptors: alpha/beta chains on mature cells and gamma/delta chains mostly on immature cells. We studied 10 patients with ataxia-telangiectasia and found that most had a relative increase of circulating T cells bearing gamma/delta receptors rather than alpha/beta receptors, as compared with normal subjects (P less than 0.001). Patients with other immune deficits, including eight with common variable immunodeficiency, one with Wiskott-Aldrich syndrome, two with hyperimmunoglobulinemia E syndrome, and one with severe combined immunodeficiency, had normal ratios of gamma/delta-bearing to alpha/beta-bearing cells. A marked predominance of gamma/delta-bearing T cells was found in a patient with a primary T-cell defect. The relative increase in gamma/delta-bearing T cells in the patients with ataxia-telangiectasia was largely accounted for by cells that reacted with the monoclonal antibody BB3, an apparently distinct subset of T cells that selectively express the C gamma 1 gene product of the T-cell receptor. Although they had normal ratios of gamma/delta-bearing to alpha/beta-bearing T cells, the patients with common variable immunodeficiency had a significant increase (P = 0.01) in the number of T cells expressing C gamma 2 that reacted with the monoclonal antibody delta-TCS-1. We conclude that the increased ratio of gamma/delta-bearing to alpha/beta-bearing T cells in ataxia-telangiectasia may reflect both a recombinational defect that interferes with T-cell and B-cell gene rearrangements and an inability to repair damage to the DNA.

The membrane phenotype of T-prolymphocytic leukaemia

Cells from 13 cases of T-prolymphocytic leukaemia (T-PLL) were studied with a battery of immunological techniques in order to define their membrane phenotype. All cases were E-rosette positive and were negative with OKT6, anti-HLA-DR, anti-Ig and M-rosettes; in 3, 20-30% of the cells had receptors for C3b. 7 cases had predominantly a 'helper/inducer' T-subset phenotype, (OKT4+, OKT8-) and 4 had a 'suppressor/cytotoxic' phenotype (OKT8+, OKT4-). Cells in 2 cases coexpressed OKT4 and OKT8 in 48% and 95% of prolymphocytes and in another, both OKT4 and OKT8 were negative. Terminal transferase (TdT) was negative by IF in all the cases, but a low positive level was detected biochemically in one. Although T-PLL appears to be heterogenous in respect of membrane phenotype, the observation of unexpected features in 8 of the cases raises the possibility that it may originate in a cell of intermediate maturation between late thymocytes and mature T-lymphocytes. These features plus the clinical manifestation of the disease - typical morphology, splenomegaly, lymphadenopathy, skin lesions, high WBC and aggressive clinical course - help define T-PLL as a distinct clinicopathological entity.

Chronic T-cell leukaemias. III. T-colonies, PHA response and correlation with membrane phenotype

The functional capacity of T lymphocytes from 28 cases of chronic T-cell leukaemia--T-CLL, T-PLL, T-LCL and Sézary syndrome--was evaluated in a T-colony forming system and in a PHA response assay. Reduced or absent T-colony growth was observed in 23 cases (82%) while in five the growth was normal. Although a good correlation was generally observed between colony formation and PHA transformation, in a few cases a low PHA response was accompanied by moderate colony growth and vice versa. Characterization of the leukaemic T lymphocytes using monoclonal antibodies (OKT series) indicates that cases with a helper/inducer phenotype (OKT4+) showed moderately reduced or near-normal T-colony numbers, whilst cases with a suppressor/cytotoxic phenotype (OKT8+)--confined to T-CLL in this study--had a very low or absent colony growth. The functional abnormalities reported here suggest that neoplastic T-cells with a helper/inducer phenotype show a low proliferative response in the assay systems used, although expressing mature T-cell characteristics. The low growth observed in T-CLL confirms that cells with a suppressor/cytotoxic phenotype form few T-cell colonies.

Unusual T-cell phenotype in advanced B-chronic lymphocytic leukaemia

T-lymphocytes isolated by E-rosetting from 22 patients with B-cell chronic lymphocytic leukaemia (B-CLL) showed membrane phenotype features distinct from those of normal T-lymphocytes. These changes were particularly marked in advanced disease (Rai stages II, III, IV and WBC over 100x10(9)/l). The most significant finding was the demonstration, in 10 cases, of a major population of E-rosette positive cells (40-80%) unreactive with the OKT monoclonal antibodies against mature or immature T-cells; 15-30% of the cells were unreactive in seven other cases. A significant reduction in OKT4 positive (helper) lymphocytes was seen in 18 cases. The proportion of OKT8 positive cells was increased in two and normal or low in the rest. Only four patients with early disease (stages 0 and I) had a normal T-cell phenotype. These findings could explain abnormalities previously described in the T-lymphocytes of B-CLL and provide new insights into the pathogenesis of the disease.

Heterogeneity of B-cell leukemias demonstrated by the monoclonal antibody FMC7

A new monoclonal antibody, FMC7, was studied in 68 patients with chronic B-cell leukemia. All 17 cases of prolymphocytic leukemia (B-PLL) and 8 of 9 of hairy-cell leukemia were positive. In contrast, FMC7 was negative in 32 of 38 chronic lymphocytic leukemias (B-CLL; p less than 0.001) and 4 cases of B-cell lymphoma. Four of the 6 positive B-CLL cases were in "prolymphocytoid" transformation; two of them had bright membrane Ig (SmIg) staining and may represent an intermediate form between B-CLL and B-PLL. Although there was a tendency for the intensity of the immunofluorescence reaction with FMC7 and SmIg to change in parallel, FMC7 did not correlate with any Ig class. In addition, almost all FMC7-negative B-CLL had weak expression of SmIg. FMC7 is different from other monoclonal antibodies raised against B-lineage cells in that it recognizes only some subsets, presumably those at a late stage of maturation. This property confers diagnostic potential to this reagent and may contribute to the better characterization of the B-cell neoplasias.

Stimulation of chronic lymphatic leukaemia cells by pokeweed mitogen after treatment with neuraminidase-galactose oxidase

CLL lymphocytes gave a low response upon stimulation with PHA or PWM in 3-day cultures. However, after treatment with neuraminidase-galactose oxidase (NGO), in the presence of PWM, CLL lymphocytes transformed into blasts and incorporated 3H-thymidine in 3-day cultures. This response of CLL lymphocytes was similar to that given by normal lymphocytes to PWM in 3-day cultures. The best stimulation of CLL lymphocytes was achieved when conditioned medium (CM) from normal T lymphocytes was present in PWM cultures. Purified B lymphocytes from CLL (T lymphocytes and monocytes removed) did not respond to PHA or PWM. However, after NGO treatment these cells were stimulated by PWM, but only in the presence of CM. PHA failed to stimulate NGO-treated CLL lymphocytes or purified B lymphocytes. This study shows that CLL lymphocytes, which usually fail to respond to mitogens, can be stimulated by PWM to proliferate after treatment with neuraminidase-galactose oxidase (NGO). This technique of B cell stimulation has been found useful in cytogenetic studies of B cell proliferative disorders.

Cell surface and enzyme markers of cord blood lymphocytes

Human cord blood (CB) lymphocytes were studied with several markers for T- and B-cells and the results compared with those of adult peripheral blood (PB) samples. The proportion of E-rosettes was significantly lower in CB (mean 24.7+/-13.5 SD) than in PB (67.5+/-7.3 SD). Treatment with neuramidase produced a marked increase in the proportion of E-rosettes in CB (mean 47 +/-13.9 SD), still below the PB values. The proportion of CB lymphocytes showing block positivity with alpha-naphthyl-acetate-esterase correlated closely with the percentage of E-rosettes in neuraminidase treated cells. The percentage of H-rosettes (human RBC) was significantly higher in CB (7.2+/-6.0) than in PB (3.2+/-1.6 SD). Re-rosetting experiments showed that in CB about 30% of the E-positive cells formed H-rosettes, in contrast to 5% in PB. These findings indicate that in CB the real number of T-lymphocytes is higher than shown by conventional E-rosette formation. The proportion of B-lymphocytes, tested by surface immunoglobulins and by rosette formation with mouse RBC (M-rosettes), was similar in CB and in adult PB. A slight increase in cells with IgM on the surface was found in CB. The overall proportion of lymphocytes with negative B and T markers in CB is three times greater than in adult PB. Levels of the enzyme terminal deoxynucleotidyl transferase were marginally increased in CG; in two out of 41 samples the levels were above those found in normal bone marrow. CB may be a suitable model for the study of lymphocyte subsets with negative B and T markers in man.

Mouse RBC rosettes in chronic lymphocytic leukaemia: different expression in blood and tissues

Mouse RBC (M) rosettes were investigated on lymphocytes from peripheral blood (PB) and various tissues in twenty patients with chronic lymphocytic leukaemia and one with follicular lymphoma. In all cases studied, the percentage of M rosettes was significantly higher in PB (median 64%) than in bone marrow (median 15%) and lymph node (median 12%). These differences were statistically significant (P less than 0.01). The possibility that these differences were related to technical factors was ruled out by a number of control procedures. It is suggested that the different expression of M rosette formation reflects the property which determines whether a lymphocyte enters the peripheral blood or remains fixed in the tissues.

Clinical staging and immunological findings in chronic lymphocytic leukemia

Several immunological markers were tested in 52 untreated cases of chronic lymphocyte leukemia (CLL) to see whether their frequency differed according to the clinical stage in Rai's system. The leukemic cells in all cases had B-cell features as shown by monoclonal immunoglobulins on the cell surface (SmIg) and/or a high percentage of mouse RBC (M)-rosettes. Of the two B-cell markers, the M-rosette test was the more consistently positive. The frequency of these markers did not correlate with clinical staging. The percentage of T-lymphocytes, low in all cases, was found to correlate inversely with the lymphocyte counts, which were higher in advanced stages. The absolute number of T-lymphocytes was above normal in most cases, but did not relat to staging. At least one of the serum Ig, most commonly IgA, was decreased in 87% of cases. Low Ig were slightly less common in Stages 0-I than in advanced stages (II-IV). The above features were also examined in two groups of CLL patients: with stable (9) or progressive (16) disease. The only difference observed between the two groups was that surface IgM only was present in 1 of the 9 stable cases as compared to 9 of the 16 progressive ones. Our findings do not support the suggestions that surface IgM is a feature of a benign form of CLL or that the absolute number of T-lymphocytes correlates with prognosis.

'Prolymphocytoid' transformation of chronic lymphocytic leukaemia

We report clinical, morphological and surface marker studies on seven patients with the common type of chronic lymphocytic leukaemia (CLL) whose disease underwent an insidious though progressive change in character with increasing refractoriness to treatment. This transformation was accompanied by the appearance of a population of immature-appearing cells in the peripheral blood which resembled prolymphocytes, both at light and electron microscopy. The characteristic morphological feature was the presence of two distinct populations of cells, the typical CLL lymphocytes and the 'prolymphocytoid' cells. These cells retained the surface characteristics of CLL, i.e. the information of mouse RBC rosettes and sparse surface-bound immunoglobulin. This transformation can be distinguished by morphological and surface marker criteria from acute leukaemia occurring in CCL, Richter's syndrome and prolymphocytic leukaemia. The recognition of this group of CLL patients may add a new prognostic index to CLL and may help plan subsequent trials for the treatment of the disease.

Ultrastructural, cytochemical and surface marker analysis of cells during blast crisis of chronic granulocytic leukaemia

The blast cells of 19 patients with Ph1-positive chronic granulocytic leukaemia (CGL) in blast crisis (BC) were studied by means of several techniques: morphology, cytochemistry, ultrastructure, surface markers and the enzyme terminal transferase. Cells of BC were, in most case, extremely undifferentiated by morphology and cytochemistry. Our data showed that in 80% of cases the cells in BC were myeloid and in 20% they were "lymphoblastic". The M1, M2 and M3 forms (FAB classification) were rare in CGL BC compared with acute myeloid leukaemia (AML). A megakaryoblastic type was seen in 15% of BC cases; the existence of this form could only be demonstrated by electron microscopy. The limphoblastic BC cells were, as in acute lymphoblastic leukaemia (ALL), positive with Greaves' anti-ALL serum and had elevated levels of terminal transferase. A case of a 17-year old boy presenting as ALL, reverting to chronic-phase CGL after complete remission and developing terminally a myeloid BC is described in detail. This case helps to illustrate a new form of natural history of CGL unveiled by the present study.

Acid-phosphatase reaction in acute lymphoblastic leukaemia

The diagnostic value of the acid-phosphatase reaction was assessed double-blind in 148 cases of acute lymphoblastic leukaemia (A.L.L.) classified by surface-membrane markers and entered into the M.R.C. U.K. A.L.L. trials. 90% of cases of T-A.L.L. showed a positive reaction in the majority of blast cells, while only 2% of common-A.L.L. and 10% of null-A.L.L. were positive. This cytochemical reaction distinguished the more aggressive form of A.L.L. any may aid the choice of therapy.

Phagocytic potential of leukaemic B-lymphocytes

Phagocytosis of small latex particles was demonstrated by light and electron microscopy in a proportion of cells from B-lymphoproliferative disorders including chronic lymphocytic, prolymphocytic and hairy cell leukaemia. It was not observed in a case of T-chronic lymphocytic leukaemia or in normal lymphocytes. A significant correlation was observed between the binding of latex to the lymphocyte surface and the degree of phagocytosis. It is suggested that the phagocytic activity of leukaemic B-lymphocytes is mediated through their Fc receptor and that this property may also be present in normal B-cells. Among mononuclear cells, therefore, phagocytosis can no longer be considered exclusively a property of monocytes.

5' nucleotidase activity in leukaemic lymphocytes

The enzyme 5' nucleotidase (E.C.3.1.3.5.) is present in lymphocytes isolated from the blood of normal subjects. The activity was extremely low in lymphocytes from 17 patients with B lymphocytic leukaemias. Removal of normal lymphocytes from the B-cell leukaemic samples decreased further the enzyme activity. Moderately low values were observed in three cases of T-ALL and in the cells from a case of Sézary syndrome. In contrast, normal or high values were observed in three cases of ALL in which T and B markers were not demonstrable and in two of T-CLL. No differences were observed in partially purified subpopulations of normal B and T cells.

Mouse red-cell rosettes in B-lymphoproliferative disorders

A high proportion of peripheral-blood lymphocytes formed spontaneous rosettes with mouse red cells in 22 out of 23 cases of chronic lymphocytic leukaemia (CLL); the proportion was significantly higher than in 19 cases of other B-lymphoproliferative disorders (non-CLL group) and in 19 normal controls. Intermediate findings were obtained in 10 cases of "hairy" cell leukaemia. Blast cells from various types of acute leukaemia did not bind mouse red cells. Pre-treatment of the lymphocytes with neuraminidase led to a significant increase in the proportion of rosettes in CLL only. This test may prove useful in distinguishing CLL from other B-lymphoproliferative disorders, particularly prolymphocytic leukaemia.