Myeloma and pernicious anaemia

Characteristics of Vitamin B12 Deficiency in Patients With Plasma Cell Disorders

BACKGROUND

Although increased rates of vitamin B12 deficiency have been reported in patients with plasma cell dyscrasias (PCDs), no mechanism has been identified. Excess free light chains (FLCs) could disrupt the renal proximal tubule receptors where B12 is reabsorbed. We sought to characterize the relationship between B12 deficiency and PCDs. We hypothesized that rates of B12 deficiency would be highest in patients with PCDs with high FLC burdens.

METHODS

We reviewed the electronic medical records of 501 patients who met inclusion criteria (diagnosed PCD with documented serum B12 and FLC levels) to obtain clinical data recorded prior to patients' lowest B12 levels.

RESULTS

Overall, 20.0% of patients had low vitamin B12. There was an expected negative correlation between estimated glomular filtration rate and FLC (r_s = -0.317; P < .001). However, low B12 levels were more prevalent in patients with preserved renal function (P = .047). Low B12 was associated with lower mean corpuscular volume (P = .037).

CONCLUSION

Higher FLC burden was associated with poor kidney function but not with low B12. Low B12 was seen more commonly in patients with preserved kidney function. Mean corpuscular volume was statistically but not clinically different between patients with low and normal B12 and, therefore, may not be a reliable indicator of B12 deficiency in PCDs. Prospective studies should compare B12 metabolites with FLC levels. Detection of B12 deficiency among patients with PCDs remains important to reduce neurologic dysfunction and cytopenias, sequelae common to B12 deficiency and PCDs.

High immune responsiveness in a family with multiple paraproteinaemia and autoimmune thyroid disease

Immune responsiveness was investigated in a family comprising 12 first- and second-degree relatives, one of whom had kappa-myelomatosis, one IgA-lambda paraproteinaemia, two Graves' disease and a further two thyroid antibodies without disease. Relatives by marriage served as controls. Parameters of immune capacity studied were the humoral and cellular immune response to haemocyanin of Helix pomatia (HPH), dinitrochlorobenzene (DNCB) skin reactivity and in vitro lymphocyte proliferation capacity to phytohaemagglutinin (PHA). Mean antibody titres to HPH were higher in the family than in the control group in all main Ig classes and IgG subclasses after primary and secondary immunization, and the difference was statistically significant for IgG, IgG2 and IgG4 titres. This could not have been predicted from the (normal) serum Ig levels in this family. In vitro lymphocyte proliferation capacity to HPH after primary and secondary immunization was also significantly increased. DNCB skin reactivity also tended to be high in the family, whereas PHA-induced lymphocyte proliferation was normal. These findings support the idea that myelomatosis clusters in families with immune dysregulation.

Prevalence of vitamin B12 deficiency in patients with plasma cell dyscrasias: a retrospective review

BACKGROUND

To the authors' knowledge, the prevalence of vitamin B12 deficiency among patients with plasma cell dyscrasias (PCD) is largely unknown. Identifying this vitamin deficiency in such patients could help improve their anemia and increase their tolerance to potentially neurotoxic agents.

METHODS

The authors retrospectively reviewed the charts and laboratory results of 664 consecutive patients diagnosed with PCD who had their vitamin B12 and folate status evaluated between 1997 and 2001 at the Cleveland Clinic Multiple Myeloma Research Program. The patients were screened for vitamin B12 deficiency using serum vitamin B12 and methylmalonic acid.

RESULTS

Of the 664 patients whose medical charts were reviewed, information on vitamin B12 status was available for 522 patients (78%). Among these 522 patients, 71 (13.6%) had laboratory-defined vitamin B12 deficiency and the remaining 451 patients (86.4%) did not. On univariate analysis, vitamin B12 deficiency correlated with immunoglobulin A (IgA) PCD (P = 0.04), higher mean corpuscular volume (P = 0.008), and longer follow-up (P = 0.048). In a covariate adjusted model, only the presence of IgA PCD was associated with an increased prevalence of vitamin B12 deficiency (P = 0.003).

CONCLUSIONS

Vitamin B12 deficiency was prevalent in patients with PCD, especially in patients with the IgA subtype. Serum vitamin B12 measurements should be part of the initial evaluation and subsequent workups for anemia in patients with PCD.

Cancer risk following pernicious anaemia

A computer-based file of all Veterans Administration (VA) hospitalisation records for the period 1969-1985 was used to identify and follow for cancer development a cohort of 5,161 white males with pernicious anaemia. A total of 34,915 person-years were accrued, with an average length of follow-up of 6.8 years. A total of 481 cancers were diagnosed, slightly higher than the number expected (SIR = 1.2). Significant excesses were observed for cancers of the buccal cavity and pharynx (1.8) and stomach (3.2), and for melanoma (2.1), multiple myeloma (2.1), myeloid leukaemia (3.7) and other and unspecified leukaemia (4.0). Although the excess for stomach cancer was highest in the first year after diagnosis in a VA hospital, risks of 2-fold or greater persisted throughout the study period. The majority of leukaemias occurred in the first year of follow-up, but some excess risk continued beyond this time. The elevated risk of buccal and pharyngeal cancers may relate to heavy alcohol intake among this population, although risks remained high even when the cohort was restricted to patients without an admission for alcoholism. Although an elevated risk of stomach cancer among pernicious anaemia patients is consistent with most previous surveys, the low absolute risk suggests that the cost-effectiveness of intensive screening should be reassessed.

Neuropathy and motor neuron syndromes associated with plasma cell disease

Increasing numbers of patients are being recognized with neurological abnormalities associated with the immunochemical changes of plasma cell disease. To illustrate the wide spectrum of clinical disorders that can be found, I discuss in detail 5 patients: 2 with neuropathy, 3 with amyotrophic lateral sclerosis (ALS), all of whom had serum monoclonal paraproteinemia. In addition, I report in tabular form 6 patients with paraproteinemia and the following clinical presentations: 1) systemic lupus with polyneuropathy and severe cerebritis, 2) myasthenia gravis with thymoma, 3) polymyositis, 4) polymyositis, arthritis and Grave's disease, 5) relapsing polyneuritis (one of the original patients diagnosed by Austin) and 6) ALS, dystonia and parkinsonism. Major improvements in clinical condition occurred sometimes, but not always, coincident with reductions in the levels of the paraprotein using prednisone, cyclophosphamide, chlorambucil and plasma exchange treatments even in some of the patients who had the clinical appearance of ALS. Patients with neuromuscular diseases should be routinely screened with serum immunoelectrophoresis for monoclonal gammopathy. If a monoclonal gammopathy is found and if the disease is serious, then those patients should be treated as if they had an autoimmune disorder.

Vitamin B12 metabolism in myelomatosis

In 38 patients with myelomatosis the serum cobalamin varied from 34 pmol/1 to 404 pmol/1, median 181.5 pmol/1, which is significantly lower than the levels in 22 control persons with range 173-535 pmol/1, median 265 pmol/1. In spite of low serum cobalamin no symptoms of vitamin B12 deficiency could be demonstrated in any of the patients, except for the one patient who had a serum cobalamin of 34 pmol/1. Mean values for Hb, MCV, PCV, serum lactate-dehydrogenase, adjested red cell folate and nucleated neutrophil count were similar in a group of patients with a serum cobalamin below 160 pmol/1 and a group of patients with higher serum cobalamin values. The decrease in serum cobalamin is due in part to a reduction in the major cobalamin binder (TC-I) in serum. Measuring serum cobalamin in relationship to gastric acis secretion, we found a significantly higher frequency of hypo- and achlorhydria in patients with serum cobalamin below 160 pmol/1 although the intestinal absorption of vitamin B12 was normal by a Schilling test. Although our finding of low saturation of TC-I in serum seems to demonstrate decreased vitamin B12 content in the body in myelomatosis, the lack of evidence for a functional vitamin B12 deficiency speaks against giving a supplement to patients with myelomatosis.

Nonmalignant monoclonal immunoglobulinemia, pernicious anemia and gastric carcinoma. A model of immunologic dysfunction. Report of two cases and review of the literature

The association of an autoimmune disease with a monoclonal immunoglobulin is not exceptional and most probably results from a dysfunction of the immunologic apparatus. This study describes two patients with monoclonal immunoglobulin A (IgA) and M (IgM) gammopathy, respectively, in whom pernicious anemia and finally gastric carcinoma developed. One patient had autoantibodies to gastric parietal cell and to thyroid microsomal antigen which could not be identified with the M-component. This observation, together with the fact that pernicious anemia occurred in one case before and in the other case after the discovery of M-component, suggests that different clones of cells were responsible for both disorders. Sixteen cases in which the patients had the same association have been collected from the literature and the data are compared with ours.

Incidence and pathogenesis of megaloblastic erythropoiesis in multiple myeloma

Intermediate megaloblastic changes occurred in six (19%) of 32 patients with multiple myeloma and trivial megaloblastic changes in a further ten (31%). Folate deficiency was the predominant cause of these changes and in at least two patients was sufficiently severe to contribute to anaemia. Folate deficiency appeared to be due to exćess folate utilization by the tumour and was related to the amount of paraprotein produced daily. Five of the 32 patients had subnormal serum B(12) levels. Reduction in the serum B(12) level was related to the reduction in the normal circulating immunoglobulins and occurred despite normal B(12) absorption. Possible explanations for this finding are discussed.