Overview.
Castleman’s disease renal damage refers to the renal damaging disease caused by Castleman’s disease. Patients with this disease mainly present with proteinuria and anemia, often accompanied by other systemic or organ involvement, such as multiple lymph node enlargements throughout the body.
Etiology
The cause of the disease is not clear, but may be related to viral infections (especially human herpesvirus 8 infection), cytokines (such as vascular endothelial growth factor, interleukin-6, tumor necrosis factor-alpha), and abnormal function of antigen-presenting cells.
Symptoms
The vast majority of patients present with glomerular involvement and almost all have proteinuria. Most patients have hypergammaglobulinemia with hypocomplementemia and anemia, and some patients present with nephrotic syndrome, acute or progressive nephritic syndrome, and occasionally tubulointerstitial lesions. More than half of the patients present with acute kidney injury at the time of presentation, and some have hypertensive manifestations. The disease is often associated with other systemic or organ involvement, such as multiple lymph node enlargements throughout the body, commonly in the neck, submandibular, supraclavicular, axillary and inguinal areas.
Examination
1. Laboratory examination
Most patients can see microscopic hematuria. In patients with moderate or severe anemia, thrombocytopenia can be seen to (26-84)×109/L. Erythrocyte sedimentation rate is increased to different degrees. More than half of the patients have elevated C-reactive protein; a few patients are positive for anti-glomerular basement membrane antibody, anti-neutrophil cytoplasmic antibody or anti-nuclear antibody.
2. Histopathologic examination
Lymphoid hyperplasia and renal lesions can be seen.
Diagnosis
Castleman’s disease renal damage can be diagnosed according to the physical examination of multiple enlarged lymph nodes and the presence of histopathological changes of chronic lymphoproliferative disease and renal lesions. Imaging and lymph node biopsy can be done if necessary to prevent missed diagnosis and misdiagnosis.
Differential diagnosis
(1) Connective tissue disease: lymph nodes show non-specific hyperplasia, and plasma cell infiltration is sometimes seen in lymph nodes of rheumatoid arthritis. Differences can be made on the basis of clinical symptoms, laboratory tests and histopathologic changes in lymph nodes.
(2) Kimura’s disease: mostly manifested as head and neck mass with local lymph node enlargement, often accompanied by blood eosinophilia and elevated immunoglobulin IgE; lymph node biopsy can see lymphoid follicular hyperplasia and active growth center, paracortical area eosinophilic infiltration. Based on the clinical manifestations and histopathological changes of lymph nodes, it can be differentiated from Castleman’s disease renal damage.
Treatment
Plasma exchange and methylprednisolone shock therapy can be used for the treatment of renal damage in Castleman’s disease. Depending on the severity of the disease, COP (cyclophosphamide + vincristine + prednisolone), CHOP (COP + doxorubicin) and RCHOP (CHOP + rituximab) can be used.
Prognosis
Immediate treatment results are favorable, and long-term regression needs to be followed up.