Heavy Chain Disease in the United States: Analysis of Incidence, Patient Characteristics and Survival Outcomes

BACKGROUND Heavy chain diseases (HCDs) are B-cell neoplasms characterised by production of monoclonal (M) protein consisting only of immunoglobulin heavy chain without a bound light chain. Three types have been recognized- IgA alpha HCD (most common, a form of extra nodal marginal zone lymphoma of mucosal associated lymphoid tissue aka immunoproliferative small intestinal disease [IPSID], Mediterranean lymphoma or Seligmann disease], IgG gamma HCD (aka Franklin's disease, variant of lymphoplasmacytic lymphoma) and IgM mu HCD (rarest, resembles chronic lymphocytic leukemia). Limited data is available regarding the epidemiology, survival patterns, and incidence of second primary malignancies in patients with HCD in the Unites States. MATERIALS AND METHODS We performed a retrospective analysis using SEER* stat version 8.3.9 statistical software and November 2020 submission of SEER 18 registry which covers ~ 27.8 % of US population based on the 2010 census. We identified all cases > 1 years old diagnosed with Heavy chain disease between 2000 and 2018 using International Classification of Diseases for Oncology edition 3 (ICD-O-3) code 9762/3. We analyzed survival using Kaplan- Meier method, and MP-SIR session was used to calculate the risk of second primary malignancy. RESULTS A total of 64 cases of HCD were identified. Most common primary sites of involvement were bone marrow (82.8%), lymph nodes (9.3%), GI tract (3.1%), others (4.6%)- spleen, blood and vertebral column. The crude, age-adjusted to 2000 US standard population and age-specific incidence rate of HCD in the United States is < 1/100,000 respectively. The median age at diagnosis is 68 years with incidence in males being about 1.3 times that of females. Bimodal age distribution was observed, with peak incidence between ages 60-64 and 75-79 [Figure 1]. In our entire cohort, 82.8% (n=53) patients were Caucasians, 15.6 % (n=10) patients were African Americans, and 1.5% (n=1) patients were American Indian/Alaska Native. Among Caucasians, 56.6% (n=30) patients were males, and 43.3% (n=23) patients were females. Between 2000-2018, the maximum cases (n=7 each) were diagnosed in the year 2002 and 2008 [Figure 2] The median overall survival for the entire cohort was 48 months (95% CI: 35- 61). Overall survival rates of all ages, sex and race at 1 year, 2 year and 5 years were found to be 86.1%, 71.4%, 57.8% respectively. OS at 5 years declines after 70 years .Patients with HCD are at risk of developing subsequent solid and haematological malignancies within 5 years of diagnosis. 9 (14 %) cases developed SPMs: urinary bladder (n=1), lung and bronchus (n=2), Hodgkin-nodal (n=1), Non-Hodgkin Lymphoma -extra nodal (n=1), GI cancers [stomach (n=1), esophagus (n=1) and ascending colon (n=1)], miscellaneous (n=1). [Figure 4]. The mean follow-up duration for new SPM was 51 months. Overall, 39 patients died: 3 (4%) from miscellaneous malignant cancer and 11 (17%) patients from haematological malignancy; the most common being Non-Hodgkin lymphoma (n=8), followed by Hodgkin lymphoma (n=1), Multiple myeloma (n=1) and leukemia (n=1). CONCLUSIONS HCD is an extremely rare haematological malignancy. The incidence of HCD is proportionately higher among Caucasians as compared to other races, with no reported case among Asian or Pacific Islanders. Among Caucasians, males and females have approximately equal risk of acquiring HCD. Most patient die because of their primary haematological malignancy. We recommend close follow-up for at least the first 5 years after initial diagnosis. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Heavy Chain Disease Reviewed on MALDI-TOF

Heavy Chain Disease (HCD) is a group of rare B-cell proliferative disorders. Diagnosis depends on the detection of a truncated heavy chain with no associated light chain, often done by serum or urine immunofixation. This approach has been reported to have low specificity, since associated light chain bands are sometimes not visible and heavy chain bands can be mistaken for polyclonal bands. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) offers improved sensitivity in detecting monoclonal immunoglobulins. Truncation is thought to happen in the constant heavy chain (CH1) region, detected as a fragment of mass 27,000 Da on MALDI-TOF. Other mass patterns have not been reported in the literature. In this study, frozen serum samples from 8 heavy chain disease patients were analyzed by MALDI-TOF mass spectrometry. Spectra were reviewed on Mass-Fix software and visually inspected for monoclonal peaks. We detected two types of patterns for the IgG heavy chain disease. One pattern shows an IgG heavy chain with truncated mass (27,000 Da vs. 50,000 Da) and another in which the mass of the IgG heavy chain is greater than normal (65,000 Da). Follow-up work demonstrates that these are most likely dimers of truncated heavy chains. Thus, mass spectrometry-based immunofixation can provide new insights into heavy chain disease biology, mechanism, and progression, which are not identified by traditional diagnostic methods.

Gamma heavy chain disease associated with rheumatoid arthritis: a case report

Background Gamma heavy chain disease (γ-HCD) is a monoclonal gammopathy defined by an abnormal clonal and isolated production of incomplete heavy chain gamma (γ), unable to bind with light chains kappa or lambda. This disease is rare and remains poorly described. Its association to lymphoid neoplasm is well established, but exceptional forms of γ-HCD may also accompany auto-immune diseases. We report here a new case of γ-HCD characterized by an indolent course with a 4-year follow-up, and its association with quiescent rheumatoid arthritis (RA). Case presentation We report the case of a 85-year old French white man followed for quiescent anti-CCP+ rheumatoid arthritis treated by prednisolone 4 mg/day and hydroxychloroquine 200 mg/day since 10 years, and a monoclonal gammopathy of undetermined significance for 6 years, who was hospitalized for costal fractures after a fall. Serum protein electrophoresis showed a stable small monoclonal peak, and capillary electrophoresis/immunosubtraction technique identified an isolated clonal γ-heavy chain (HC). Bone marrow aspiration was normal and he had no other lymphoproliferation. The monoclonal peak remained stable after 4 years of follow-up. Conclusions In case of monoclonal peak without complete monoclonal Ig on serum protein electrophoresis, the diagnosis of γ-HCD should be discussed and capillary electrophoresis/immune-subtraction is a mean to detect isolated monoclonal heavy chain (HC). Gamma-HC disease is rare, may be associated to RA, and may have an indolent course.

Light chain proteinuria revealing mu-heavy chain disease: an atypical presentation of Waldenström macroglobulinemia in two cases

Not available.

Gamma heavy chain disease complicated by pulmonary hypertension, which was successfully treated with lenalidomide

Heavy chain disease (HCD) is a rare B-cell proliferative neoplasm that is characterised by the production of truncated monoclonal immunoglobulin heavy chains without light chains. Gamma HCD is a subgroup of HCD. A 67-year-old man was admitted to our hospital with dyspnoea and lower leg oedema. Based on the results of heart catheterisation, he was diagnosed with pulmonary hypertension. Laboratory tests revealed an elevated level of IgG, and serum immunoelectrophoresis showed that IgG was a monoclonal gamma heavy chain without light chains. Finally, he was diagnosed with gamma HCD complicated by pulmonary hypertension. Bortezomib and dexamethasone therapy was initiated, but became refractory within 8 months. Therefore, the treatment was switched to lenalidomide and dexamethasone therapy, and the disease has been stably controlled for more than 2 years. To the best of our knowledge, this is the first case of gamma HCD being successfully treated by lenalidomide and dexamethasone therapy.