Serum immunoglobulins in chronic lymphocytic leukemia

Prevalence and the impact of hypogammaglobulinemia in newly diagnosed chronic lymphocytic lymphoma patients

Objective

To examine the prevalence of hypogammaglobulinemia in chronic lymphocytic lymphoma (CLL) patients and to test the hypothesis that patients with hypogammaglobulinemia have a distinct clinical profile and outcome.

Methods

Immunoglobulin levels (IgA, IgG, IgM, IgE) were measured in newly diagnosed, treatment naïve banked samples of 150 patients with CLL followed prospectively for outcomes. Cox regression models were used to assess the effects of clinical variables on overall survival (OS).

Results

The median age of the selected CLL cohort was 64 years with a male predominance; 96.2% of the patients were white. Fifty-nine deaths occurred during a median follow up of 6.8 years. Hypogammaglobulinemia in CLL was common in our cohort with 88 (58.7%, 95% CI: 50.4-66.6%) patients having a measurable isotype deficiency. The most common Ig deficiency was IgM (44.0%). IgA deficiency or low IgE was associated with higher Rai stages as well as with higher white blood cell counts at presentation. Any immunoglobulin deficiency was not associated with overall survival.

Conclusion

A significant proportion of treatment-naïve CLL patients had underlying Ig deficiencies - both in isolation and in isotype combinations. Although a deficiency of IgA or IgE was associated with more severe disease at presentation, the impact of this association was mild.

IgA levels at diagnosis predict for infections, time to treatment, and survival in chronic lymphocytic leukemia

To better understand the relationship between baseline immunoglobulin measurements and subsequent clinical outcomes in chronic lymphocytic leukemia (CLL), we performed a retrospective analysis on 660 patients with CLL (72%), monoclonal B-cell lymphocytosis (MBL) (13%), and small lymphocytic lymphoma (SLL) (14%), diagnosed between 2005 and 2014 at CancerCare Manitoba. Of 511 patients who had their first immunoglobulin level determined within 3 months of diagnosis, abnormal (either increased or decreased) immunoglobulin M (IgM), IgG, and IgA values were observed in 58% of patients with CLL, 27% of patients with MBL, and 20% of patients with SLL. Immunoglobulin deviances were similar for MBL and CLL Rai stage 0 and for SLL and Rai stages I and II; for CLL, IgG and IgA abnormalities occurred with increasing frequency with advancing Rai stage. In contrast, the frequency of IgM abnormalities was similar in all patient groups. IgA abnormalities significantly correlated with high β2-microglobulin (B2M) expression, whereas abnormal IgG and IgA levels were associated with the use of IGHV1-69, 3-21, and 3-49 subtypes. Increases in IgG or IgM were commonly associated with the presence of a CLL-type M-band, whereas oligoclonal bands were frequently observed with increased IgA levels. Although abnormal levels of IgG and IgA at diagnosis were independent predictors for future immunoglobulin replacement, only abnormal IgA levels were associated with shorter time to first treatment and overall survival. These findings indicate that both reduced and elevated levels of IgG and IgA at diagnosis are important and independent prognostic markers for infection in CLL, with IgA being more relevant as a marker of disease progression and survival.

Targeting the IL-17/IL-6 axis can alter growth of Chronic Lymphocytic Leukemia in vivo/in vitro

The tumor microenvironment (TME) is critical to the longevity of tumor B cells in chronic lymphocytic leukemia (CLL). Bone marrow mesenchymal stem cells (BMMSCs) and the cytokines they produce including IL-6 are important components of the TME in CLL. We found BMMSCs supported the survival of CLL cells in vitro through an IL-6 dependent mechanism. IL-17 which induces IL-6 generation in a variety of cells increased production of IL-6 both in CLL cells and BMMSCs in vitro. In a xenograft CLL mouse model, BMMSCs and the culture supernatant of BMMSCs increased engraftment of CLL cells through an IL-6 mediated mechanism with human recombinant IL-6 showing similar effects in vivo. Human recombinant IL-17 treatment also increased CLL engraftment in mice through an IL-6 mediated mechanism. Plasma of CLL patients showed elevated levels of both IL-6 and IL-17 by ELISA compared with healthy controls, with levels of IL-6 linearly correlated with IL-17 levels. CLL patients requiring fludarabine based chemotherapy expressed higher levels of IL-6 and IL-17, while CLL patients with the lowest levels of IgA/IgM had higher levels of IL-6, but not IL-17. These data imply an important role for the IL-17/IL-6 axis in CLL which could be therapeutic targets.

Antibodies against Pneumococcal Capsular Polysaccharides and Natural Anti-Galactosyl (Alpha-Gal) in Patients with Humoral Immunodeficiencies

Humoral deficiencies represent a broad group of disorders. The aim of the study was to compare the levels of antibodies against pneumococcal capsular polysaccharides (anti-PCP) and natural anti-galactosyl (anti-Gal) antibodies in (1) patients with chronic lymphocytic leukaemia (CLL), (2) patients with common variable immunodeficiency (CVID), and (3) a healthy population and to explore their diagnostic and prognostic potential. Serum immunoglobulin levels and levels of anti-Gal IgG, IgA, and IgM and anti-PCP IgG and IgG2 were determined in 59 CLL patients, 30 CVID patients, and 67 healthy controls. Levels of IgG, IgA, IgM, anti-Gal IgA, anti-Gal IgM, and anti-PCP IgA were lower in CLL and CVID patients than in healthy controls (p value for all parameters < 0.0001). Decrease in the levels of IgA, IgM, anti-Gal IgA, and anti-PCP IgA was less pronounced in the CLL group than in the CVID group. IgA decline, anti-Gal IgA, anti-PCP IgA, and anti-PCP IgG2 were negatively correlated with CLL stage. We devise the evaluation of anti-Gal antibodies to be a routine test in humoral immunodeficiency diagnostics, even in cases of immunoglobulin substitution therapy. Significant reductions, mainly in anti-Gal IgA, IgM, and anti-PCP IgA levels, may have prognostic importance in CLL patients.

Clinical relevance of hypogammaglobulinemia, clinical and biologic variables on the infection risk and outcome of patients with stage A chronic lymphocytic leukemia

The prognostic effect of hypogammaglobulinemia (HGG), clinical and biologic characteristics on the infection risk and outcome has been retrospectively analyzed in 899 patients with stage A chronic lymphocytic leukemia (CLL). Low levels of IgG were recorded in 19.9% of patients at presentation, low levels of IgM and/or IgA in 10.4% and an additional 20% of patients developed HGG during the course of the disease. Before the start of any treatment, 160 (12.9%) patients experienced at least one grade ≥3 infection requiring a systemic anti-infective treatment and/or hospitalization. While IgG levels at diagnosis were not associated with an increased risk of grade ≥3 infection or with an adverse outcome, a significantly increased rate of grade ≥3 infections was recorded in patients with unmutated IGHV (p=0.011) and unfavorable FISH aberrations (p=0.009). Late onset HGG, more frequently recorded in patients with Rai stage I-II (p=0.001) and unmutated IGHV (p=0.001), was also associated with a higher rate of severe infections (p=0.002). These data indicate that, stage A patients with clinical and biologic characteristics of a more aggressive disease develop more frequently late onset HGG, grade ≥3 infections and require a closer clinical monitoring.

Hypogammaglobulinemia in newly diagnosed chronic lymphocytic leukemia: Natural history, clinical correlates, and outcomes

BACKGROUND

Although hypogammaglobulinemia is a well recognized complication in patients with chronic lymphocytic leukemia (CLL), its prevalence at the time of CLL diagnosis, and association with novel prognostic markers and clinical outcome is not well understood.

METHODS

All patients at the Mayo Clinic between January 1999 and July 2013 who had newly diagnosed CLL and had a baseline assessment of serum immunoglobulin G (IgG) were included. The relation between hypogammaglobulinemia at diagnosis and the novel prognostic parameters time to first treatment (TFT) and overall survival (OS) were evaluated.

RESULTS

Of 1485 patients who met the eligibility criteria, 382 (26%) had hypogammaglobulinemia (median IgG, 624 mg/dL), whereas the remaining 1103 patients (74%) had normal serum IgG levels (median IgG, 1040 mg/dL). Patients who had hypogammaglobulinemia at diagnosis were more likely to have advanced Rai stage (III-IV; P = .001) and higher expression of CD49d (P < .001) compared with patients who had normal IgG levels. Although the median TFT for patients who had hypogammaglobulinemia was shorter compared with that for patients who had normal IgG levels (3.8 years vs 7.4 years; P < .001), on multivariable analysis, there was no difference in OS between these 2 groups (12.8 years vs 11.3 years, respectively; P = .73). Of 1103 patients who had CLL with normal IgG levels at diagnosis and who did not receive CLL therapy, the risk of acquired hypogammaglobulinemia was 11% at 5 years and 23% at 10 years.

CONCLUSIONS

Hypogammaglobulinemia is present in 25% of patients with newly diagnosed CLL. Approximately 25% of patients who have CLL with normal IgG levels at diagnosis will subsequently develop hypogammaglobulinemia on long-term follow-up. The presence of hypogammaglobulinemia does not appear to impact overall survival.

Serum immunoglobulin levels at diagnosis have no prognostic significance in stage A chronic lymphocytic leukemia: a study of 1113 cases from the Israeli CLL Study Group

OBJECTIVES

Hypogammaglobulinemia, commonly encountered in chronic lymphocytic leukemia (CLL), is one of the main causes of morbidity and mortality; however, its prognostic significance in patients diagnosed in early stages of disease remains uncertain. The aim of this study was to evaluate the predictive power of hypogammaglobulinemia at Bonet stage A.

METHODS

Using the database of the Israeli CLL Study Group, we analyzed the relationship between low serum levels of IgG, IgA, and IgM; the presence of paraproteinemia, as well as other well-recognized prognostic markers in CLL; and time to first treatment (TTT) and overall survival. A total of 1113 patients consecutively diagnosed during the last 25 yrs with Binet stage A CLL were evaluated, and baseline information on serum immunoglobulin levels was found in 857 of the cases.

RESULTS

Overall survival times correlated with age >65 yr, male gender, the presence of lymphadenopathy, high serum beta 2-microglobulin (b2m), CD38 and ZAP-70 expression, but not with low levels of immunoglobulin or the presence of paraproteinemia. By univariate analysis, patients with low IgA levels had a shorter TTT; however, on multivariate analysis, the presence of lymphadenopathy (P 0.02), b2m (P 0.04), CD38 (P < 0.001), and ZAP-70 (P < 0.001) was the only laboratory parameters with prognostic significance.

CONCLUSIONS

In our cohort of patients with early-stage CLL, baseline hypogammaglobulinemia and the presence of paraproteinemia were not found to correlate with prognosis.

The number of cytomegalovirus-specific CD4+ T cells is markedly expanded in patients with B-cell chronic lymphocytic leukemia and determines the total CD4+ T-cell repertoire

B-cell chronic lymphocytic leukemia is associated with immune suppression and an altered T-cell repertoire with expansion of memory cells. Cytomegalovirus (CMV) is a common herpes virus that elicits a strong virus-specific T-cell immune response after infection. We studied the CMV-specific CD4(+) T-cell response in 45 patients and 35 control subjects and demonstrated that it was markedly expanded in the patient group, averaging 11% of the CD4(+) pool compared with 4.7% in controls. The magnitude of the CMV-specific CD4(+) immune response increased with disease stage and was particularly high in patients who received chemotherapy. Within this group, the CMV-specific response comprised over 46% of the CD4(+) T-cell repertoire in some patients. Serial analysis revealed that CMV-specific immunity increased during treatment with chemotherapy and remained stable thereafter. CMV-seropositive patients exhibited a markedly altered CD4(+) T-cell repertoire with increased numbers of CD45R0(+) T cells and a reduction in CD27, CD28, and CCR7 expression. Overall survival was reduced by nearly 4 years in CMV-seropositive patients, although this did not reach statistical significance. CLL patients therefore demonstrate an expansion of the CD4(+) CMV-specific immune response, which is likely to contribute to the immunological and clinical features of this disease.

Disease activity and pretreatment, rather than hypogammaglobulinaemia, are major risk factors for infectious complications in patients with chronic lymphocytic leukaemia

To identify patients at high risk of life-threatening infections, we retrospectively analysed the prevalence of infectious complications in 187 chronic lymphocytic leukaemia patients treated in our institution since 1999 and correlated them with clinical features. A questionnaire with detailed questions regarding infectious complications was mailed to patients and their general practitioners. Major infections (requiring intravenous antibiotics or inpatient treatment) were reported in 37 patients (19.8%) and minor infections (requiring oral antibiotics and outpatient treatment) in 113 patients (60.4%). Univariate analysis identified advanced disease (P = 0.02), gender (P = 0.01), duration of disease (P = 0.007), number of previous chemotherapy regimens (P < 0.001), previous therapy with purine analogues and monoclonal antibodies (P < 0.001; P = 0.019), massive splenomegaly (P = 0.03), low granulocyte count (P < 0.001), low serum immunoglobulin concentration (P = 0.005), low haemoglobin concentration (P < 0.001) and high serum lactate dehydrogenase (LDH) concentration (P < 0.001) as risk factors for major infections. In multivariable logistic regression analysis, only the number of previous chemotherapy regimens (risk ratio [RR] = 1.8; 95% confidence interval [CI] 1.2-8.0) and haemoglobin concentration (RR = 0.6; CI 0.5-0.8) remained significant for major infections. The number of previous chemotherapy regimens was the only independent risk factor for minor (RR = 7.6; CI 2.2-25.7) and varicella-zoster virus infections (RR = 2.1; CI 1.3-3.4). In untreated patients, the only risk factor for major infections was LDH concentration. Patients treated with purine analogues or autologous stem cell transplantation had a higher risk of developing viral infections. In conclusion, disease activity and pretreatment extent have a stronger impact on the risk of severe infectious complications than hypogammaglobulinaemia. Preferably, prophylactic strategies should be evaluated in patients defined by these parameters.

Infections in Patients with Hematological Cancer: Recent Developments

One of the most common complications involved in treating patients with hematologic cancer is infection. In many cases there are multiple factors that predispose these patients to infections such as neutropenia induced by therapy or bone marrow involvement, hypogammaglobulinemia, T-cell dysfunction, and mucosal damage. In addition, newer therapies have changed the spectrum of infection that is seen in these patients.

In Section I, Dr. Blijlevens discusses mucosal damage as a major risk factor for complications of cytotoxic chemotherapy. She focuses on mucosal barrier injury (MBI) as manifest in the GI tract and will describe a pathological model to explain MBI, evaluate risk factors for development of this syndrome, explain the relationship between MBI and infection, and discuss treatment and prevention of this injury.

Invasive fungal infections continue to represent a significant problem in patients with hematologic cancer. In Section II, Drs. Anaissie and Mahfouz review the latest developments in the diagnosis, prevention, and management of invasive fungal infections with a focus on a risk-adjusted approach to this problem.

Finally, in Section III, Dr. O’Brien reviews infections associated with newer therapeutic regimens in hematologic cancers. The spectrum of infections has changed with the use of purine analogs and the advent of monoclonal antibodies. The profound T-cell suppression associated with these therapies has led to the emergence of previously rare infections such as cytomegalovirus. An approach to both prophylaxis and management of these infections is discussed.

Increased serum immunoglobulin levels are common in mycosis fungoides and Sézary syndrome

BACKGROUND

Patients with cutaneous T-cell lymphoma (CTCL; mycosis fungoides [MF] and Sézary syndrome [SS]) acquire immunodeficiency and opportunistic infections.

OBJECTIVE

We attempted to determine whether abnormalities of humoral immunoglobulin levels are present.

METHODS

A retrospective analysis of serum immunoglobulin levels in patients with CTCL at baseline evaluation at a cancer center was compared to levels in patients with leukemias and levels in healthy control subjects.

RESULTS

A total of 254 of 650 patients with CTCL evaluated between 1987 and 2001 had baseline quantitative immunoglobulin levels. Mean IgG, IgA, and IgM levels were similar among all MF/SS patients versus controls. The percentages of MF/SS patients with elevated levels of each immunoglobulin class were higher than percentages in healthy controls, and elevated IgA levels occurred among late versus early patients (P =.043).

CONCLUSION

High immunoglobulin levels are more frequent in patients with MF and SS than in healthy controls, patients with chronic lymphocytic leukemia, and patients with hairy cell leukemia. High IgA levels are more frequent in late stage MF/SS.

Infections in chronic lymphocytic leukemia: risk factors, and impact on survival, and treatment

Patients with chronic lymphocytic leukemia (CLL) are at an increasing risk of infectious morbidity and mortality. Infections are generally due to bacteria and influenced by the degree of hypogammaglobulinemia; although, in more advanced stages of disease they may also be contributed by neutropenia due to bone marrow infiltration and/or cytotoxic therapy. Furthermore, defect in cell-mediated immunity appears to be a predisposing factor to infections in patients treated with newer purine analogues. Controversies surrounding the pathogenesis of infectious complications in CLL raise several questions on their management. Patients with advanced disease who receive cytotoxic therapy might qualify for antibacterial prophylaxis. Intravenous immunoglobulin (IVIG), although of scientific interest, may be of little relevance at the present time. The new growth factors should be tested in well-designed prospective studies.

Infections and serum IgG levels in patients with chronic lymphocytic leukemia

To review our policy of prophylactic treatment with intravenous immunoglobulin (i.v.IG) in chronic lymphocytic leukemia (CLL), we analyzed the infection history, serum IgG levels (S-IgG) and disease stage of 146 patients who were treated and followed at our institution in 1980-1989. S-IgG was available for 98 patients: 55% were hypogammaglobulinemic and 56% had had at least one severe infection. There were significant associations between S-IgG and the occurrence of infections (p less than 0.01) and disease stage (p less than 0.02). There was also a significant association between disease stage and occurrence of infections (p less than 0.001). Severe infections tended to accumulate in patients with subnormal S-IgG and advanced disease stage. Totally, 292 infections were recorded, and the incidence of moderate to severe infections was 0.47 per patient year. Infection mortality was high: 42 patients died of a severe infection (46% of all causes of death). Patients with a low S-IgG and advanced disease stage are the most susceptible to death from infection and would be most likely to benefit most from i.v.IG prophylaxis; however, the cost of this therapy is so high that strict individual consideration still remains crucial for treatment decisions.

Historic aspects of intravenous immunoglobulin therapy

The earliest preparations of immunoglobulins (Ig) decreased the susceptibility of agammaglobulinemic patients to infections caused by pneumococci, Haemophilus influenzae, meningococci, streptococci, and Pseudomonas aeruginosa. Intramuscular administration of such preparations was painful and traumatic, especially for children. Ethanol-fractionated Ig could not be administered intravenously (IV) because the IgG molecules tended to aggregate and thus were more likely to produce anaphylactoid reactions. New Ig preparations, isolated at low pH (e.g., pH 4) in the presence of traces of pepsin to inhibit reaggregation, were well tolerated when administered IV. Thus a new era of treatment and prophylaxis of disease using IV Ig (IVIG) was launched. The IVIG preparations revolutionized the management of virtually all immunodeficiency syndromes characterized by failure of antibody responses. Amelioration of antibody deficiency secondary to certain chronic diseases or surgical trauma can be achieved with these preparations. Newer uses of IVIG include treatment of some autoimmune diseases; in some conditions, the beneficial influences may be attributable to antiidiotype antibodies present in the IVIG. Another likely explanation is that IVIG inhibits damage to cells and tissues by antibody-mediated cellular cytotoxicity or blocks phagocytosis that is facilitated by Fc receptor mechanisms. The value of IVIG in preventing infection in patients undergoing bone marrow or organ transplantation and in the treatment and prophylaxis of life-threatening infections in neonates and premature infants also is reviewed.

Serum immunoglobulin concentrations in cattle naturally infected with bovine leukemia virus

In order to elucidate whether natural infection of BLV in cattle might induce humoral immunological responses, changes in IgG1, IgG2, and IgM concentrations in the sera of infected cattle were determined. Twelve BLV-infected cattle were used. Cattle of different breeds were classified serologically and haematologically into BLV + PL+, BLV + PL- and BLV-free groups. Ig concentrations in the sera of the three groups were quantitated using a commercial single radial immunodiffusion assay. The findings were compared to those of BLV-free cattle. The serum IgM concentrations were significantly lower in cattle with PL (P less than 0.001) than in BVL + PL- and BLV-free cattle. The IgM concentrations tended to be lower in BLV+ PL- than those of BVL-free cattle. There were no significant differences in IgG1 and IgG2 serum concentrations between the three experimental cattle groups. IgG1 was the predominant subtype in the sera of all cattle groups.

Deficient production of tumor necrosis factor by peripheral-blood monocytes in chronic lymphocytic leukemia

The production of tumor necrosis factor (TNF) by lipopolysaccharide (LPS)-triggered peripheral-blood mononuclear cells (PBM) was investigated in 23 patients with untreated B-cell chronic lymphocytic leukemia (B-CLL) and 14 control donors. Cells were stimulated at concentrations that reflect cell density in peripheral blood. Under these conditions, PBM from 11/23 of the CLL patients produced at least 10-fold less TNF as compared with controls. Monocyte numbers were decreased in percentage, while absolute numbers (normal range 233 +/- 120 X 10(3)/mm3) were decreased only in 2, normal in 17 and increased in 4 patients indicating that the deficiency is not a result of monocytopenia in most patients. Cell separation experiments indicate that after removal of leukemic B cells, percentages of monocytes return to control range and TNF production is improved (7/7). In mixing experiments, we found a suppression of TNF production in control mononuclear cells by CLL cell samples (75 X 10(6) cells/ml) in 5/19 cases, while control cells from thymus exhibited no or little suppression in these conditions. In 2-chamber experiments, leukemic samples suppress TNF production by normal monocytes across a 0.45 micron membrane indicating that a soluble factor is responsible for suppression. The factor exhibits higher stability in serum-free conditions and its molecular weight is below 20 kDa. Prostaglandins are not involved, since indomethacin did not abrogate suppression.

Serum immunoglobulins in B-chronic lymphocytic leukemia. Natural history and prognostic significance

To investigate the prognostic significance of gammaglobulin and immunoglobulin levels in chronic lymphocytic leukemia (CLL), survival studies were performed in a series of patients with that disorder. The survival probability of patients with initial levels of gammaglobulin of less than 700 mg/dl was significantly lower (P = 0.03) than in patients with initial levels of 700 mg/dl or more. Decreased initial levels of IgG and IgA also were associated with reduced survival probability (P = 0.027 and P = 0.014, respectively), whereas hypo-IgM did not show any influence on survival. When the influence on survival of gammaglobulin and immunoglobulin concentration was analyzed by Cox's multivariate model, the only variable which entered the regression at significant level was IgA (P = 0.006). As shown by the same type of analysis, the prognostic value of hypo-IgA is independent from the clinical staging. The natural history of hypogammaglobulinemia and hypoimmunoglobulinemia was investigated by sequential analysis in a series of untreated patients. The appearance of decreased levels of these globulins was found to be a continuous process developing spontaneously during the untreated course of the disease. Among factors associated with the appearance of hypogammaglobulinemia during the evolution of CLL, initial lower levels of IgG and IgA, but not IgM, were found in a multivariate analysis.

Survival and prognostic factors in chronic lymphocytic leukemia

The survival of 137 consecutive chronic lymphocytic leukemia patients, diagnosed between 1960 and 1982 and followed up at the Hematology Clinic of the Chaim Sheba Center, was correlated with demographic, clinical and laboratory data. The median survival time of the whole group was 104 months. Older age, hepatomegaly, anemia, thrombocytopenia and increased percent of lymphocytes in the peripheral blood at diagnosis were all associated with shorter survival. On the other hand, splenomegaly or lymph node enlargement did not influence survival. When divided according to both Rai's and the International Workshop staging systems, the survival of our patients seemed to be better than that reported in most previously published series of similar patients. We assume that this is related to a conservative approach to the treatment of chronic lymphocytic leukemia patients in this center.

The possible role of radiotherapy in chronic lymphocytic leukaemia: a critical review

The few clinical studies which have utilized irradiation as a treatment modality for chronic lymphocytic leukaemia (CLL) during the last two decades have led to rather conflicting and sometimes disappointing results. Low-dose total body irradiation (TBI) and extracorporeal, or mediastinal, radiotherapy did not appear to be superior to chemotherapy in most trials. Only the fractionated low-dose (600-800 rad) splenic irradiation was found to induce a long-lasting decrease of the lymphocyte count and a decrease in bone marrow infiltration in a significant proportion of cases, without any noticeable haematological toxicity. But new data is recently emerging; stratification of CLL in various subgroups, better understanding of the role of the normal T-cell subsets, better knowledge of the interaction between irradiation and haematopoiesis, and of the radiosensitivity of the various lymphocyte subpopulations. Thus one can now reconsider the possible role radiotherapy, and particularly splenic irradiation, can play as an alternative treatment to chemotherapy for CLL. Haematological toxicity is still limiting the use of TBI. The spleen irradiation avoids this drawback. Recent data suggest that this splenic irradiation could be efficient by means of several mechanisms; the successive destruction, fraction after fraction, of the part of the malignant lymphocyte clone present in the spleen is likely to be the main therapeutic explanation, with the knowledge that the lower the differentiation of the malignant clone, the more efficacious the irradiation. But in parallel, the destruction of the large subset of T-suppressors which is constantly present in the spleen may account for the improvement of the peripheral blood count after splenic irradiation, and possibly for a direct effect towards the malignant clone. With respect to these new data, splenic irradiation clearly needs further clinical evaluation in the treatment of CLL.

Defective complement activity in chronic lymphocytic leukemia

Patients with chronic lymphocytic leukemia (CLL) are at an increased risk for infections with bacteria which require complement for osponization. We explored the possibility that patients with CLL have a defect in binding the potent opsonin C3b to bacteria. Bacteria selected for these experiments included Streptococcus pneumoniae type 3, which binds C3 by activating the classical complement pathway (CCP), type 25, which can bind normal amounts of C3b by the alternative complement pathway (ACP), type 14, which can activate both the CCP and ACP, and Staphylococcus aureus and Escherichia coli, both of which activate the CCP. Bacteria were treated with normal serum or serum from 15 patients with CLL, and the bound C3b was quantified spectrophotofluorometrically. Despite normal serum concentrations of C3, C4, Factor B, C-reactive protein, and total hemolytic complement activity, all 15 CLL sera bound reduced amounts of C3b to at least one bacterial species; 9 to S pneumoniae type 3, 8 to types 14 and 25, 11 to S aureus, and 13 to E coli. Mixing normal serum with CLL serum restored C3b binding to all bacteria, suggesting a deficiency rather than an inhibitor of activity. Serum from ten hypogammaglobulinemic CLL patients bound less C3b (62.7 +/- 5% of normal) (means +/- SEM) than those with normal immunoglobulin levels (81.9 +/- 5%) (p less than .005). Nevertheless, the addition of specific antibacterial antibodies to CLL serum did not enhance C3b binding to any of the bacteria. Serum from patients with a history of a bacterial infection bound less C3b (62.3 +/- 5%) than those without a history of infections (76.1 +/- 6%) (p less than .05). Thus, there is a defect in either the activation or activity of C3 in CLL serum which may contribute to the increased incidence of infections in these patients.

Bone marrow histopathologic patterns and immunologic findings in B-chronic lymphocytic leukemia

In 82 patients with B-chronic lymphocytic leukemia, the correlations between the histopathologic bone marrow patterns (interstitial, nodular, mixed, and diffuse), serum immunoglobulin (Ig), and blood B-lymphocyte levels and T-lymphocyte levels have been analyzed. The most commonly lowered Ig class was IgM (43% of cases) followed by IgA (35%), and IgG (10%). There was a trend to a more frequent decrease of Ig levels when "advanced" bone marrow patterns (mixed + diffuse) were compared with the earlier ones (interstitial + nodular). The frequency of such a decrease was statistically significant for IgA class (P less than 0.01). The absolute number of blood T-lymphocytes was increased in the diffuse pattern (P less than 0.01).

Combined immunodeficiency preceding chronic lymphocytic leukemia

A 66-year-old female, suffering from recurrent infections of the respiratory tract, developed a severe hypogammaglobulinemia and an impaired cell mediated immunity in combination with abdominal lymphadenopathy and splenomegaly. Considering a lymphoid malignancy, an explorative laparotomy was performed. No malignancy could be established. After a follow-up of 2 years a diagnosis of chronic lymphocytic leukemia could be made. The onset of hypogammaglobulinemia 2 years before the development of chronic lymphocytic leukemia is not yet reported in the literature.

Increase in T gamma lymphocytes in B-cell chronic lymphocytic leukaemia. II. Correlation with clinical stage and findings in B-prolymphocytic leukaemia

The proportion of T gamma and T mu lymphocytes was studied in 40 cases of B-chronic lymphocytic leukaemia (B-CLL) and six of B-prolymphocytic leukaemia (B-PLL). The significant increase in T gamma cells, previously reported in two small B-CLL series, was confirmed and shown to be directly correlated with the clinical stages of the disease (P less than 0.01 to less than 0.001). The normal T mu:T gamma ratio (2.3:1) was reversed in B-CLL (1:1.4) and B-PLL (1:1.9). The proportion of T mu cells was decreased but was not related to stage. Our findings suggest that the increase in T gamma cells may be responsible for the hypogammaglobulinaemia of B-CLL. This is supported by two sets of observations. First, serum Ig levels were more often normal in cases in Stages 0 and I than in Stages II-IV (P less than 0.05), while the levels of two or three Ig classes were below normal in Stages II-IV twice as frequently. Secondly, splenic irradiation in one case was followed by a fall in the absolute number of T gamma lymphocytes, a reversion to normal of the T mu: T gamma ratio and an improvement in serum Ig levels. Thus, the imbalance in ;the regulatory T-cell subsets may provide an important clue to understand the pathogenic mechanism of the immunodeficiency in the chronic B-cell leukaemias.