Klebsiella Pneumoniae Associated Extreme Plasmacytosis
A 42-year-old man presented with high fever of 5 days' duration. He had been healthy without a noteworthy medical history and had not been in a tropical location in the recent past. On physical examination, he had an acute, ill appearance, a body temperature of 39.2℃, a pulse rate of 72 beats/minute, a blood pressure of 110/60 mm Hg, and no signs of tachypnea (22 respirations/minute). No remarkable erythroderma or lymphadenopathy was observed. There was no evidence of arthritis. No definite space-occupying lesion was noted on his neck, chest, abdomen, or pelvis by computed tomography (CT). A summary of his clinical course is illustrated in .\nLaboratory results on admission were as follows: hemoglobin level, 11.1 g/dL; white blood cell (WBC) count, 500/mm3; and platelet count, 6,000/mm3. Blood urea nitrogen (BUN; 20.1 mg/dL), creatinine (1.10 mg/dL), and calcium levels (8.4 mg/dL) were not increased. Although the alanine aminotransferase level (67 IU/L) was mildly elevated, the aspartate aminotransferase level (37 IU/L) was not. The C-reactive protein level was 44.4 mg/dL (reference range: 0.00-0.30 mg/dL). The serum immunoglobulin (Ig) and light chain measures were as follows: IgG, 22.88 g/L (reference range: 8.00-18.00 g/L); IgM, 1.08 g/L (0.038-2.460 g/L); IgA, 4.37 g/L (0.90-4.50 g/L); kappa light chain, 118.05 mg/L (3.30-19.40 mg/L); and lambda, 87.18 mg/L (5.71-26.30 mg/L). The rheumatoid factor was positive (18 IU/mL), but all the other autoimmune- related factors, including fluorescence anti-nuclear antibody, antineutrophil cytoplasmic antibody, and antibody panel for extractable nuclear antigen, were negative.\nOn chest radiography, pneumonic haziness was noted. This haziness worsened to definite pneumonic consolidation on the 4th hospital day (HD; ). Empirical intravenous antibiotic treatment with cefepime 2.0 g every 8 hours and ciprofloxacin 400 mg every 12 hours failed to improve his pneumonia or fever.\nOn the eighth HD, BM biopsy and aspiration showed 25% cellularity with marked plasmacytosis (80%), lymphoid cells (15%), and less than 5% of erythroid-myeloid-megakaryocytes. Immunohistochemical staining for kappa and lambda light chains on BM plasma cells demonstrated no light chain restriction (). The WBC count was 900/mm3, with 26% of plasma and plasmacytoid cells in peripheral blood. Cytogenetic analysis using the G-banding technique revealed a 46, XY karyotype without definite chromosomal aberration. Serum protein electrophoresis showed hypoalbuminemia and increased gamma-globulin with a polyclonal pattern. Serum protein immunoelectrophoresis and immunofixation electrophoresis showed no definite abnormal arc or band, respectively.\nK. pneumoniae was identified in both blood and sputum cultures on the eighth HD. Antibiotic susceptibility testing demonstrated resistance to ampicillin and piperacillin, while the pathogen was negative for extended-spectrum β-lactamase production. Tests for other infectious pathogens including human immunodeficiency virus, hepatitis A, hepatitis B, hepatitis C, Epstein-Barr virus, aspergillus, syphilis, legionella, pneumococcus, and mycobacterium were negative. There was no evidence of acid fast bacilli infection by direct smear, culture, or polymerase chain reaction. Considering his continuous febrile neutropenia and isolation of K. pneumonia from blood, the antibiotics were changed on the eighth HD to vancomycin 1.0 g intravenously every 12 hours plus levofloxacin 500 mg every 24 hours; his fever started to subside ().\nNo evidence of pneumonia was observed on the chest radiograph obtained on the 15th HD (). Follow-up blood cultures performed on the 15th and 20th HDs revealed no growth of bacteria ().\nBody temperature, however, elevated again to 39.5℃ on the 20th HD. CT evaluation showed multiple necrotizing consolidations on both lungs, suggesting invasive fungal infection (). A septated fungal organism was detected by CT-guided lung biopsy (). Antibiotics were changed to meropenem 1.0 g every 8 hours, amikacin 1.0 g every 24 hours, and amphotericin B deoxycholate 1.0 mg/kg every 24 hours; his clinical course improved except for intermittent low-grade fever.\nFollow-up BM biopsies and aspirations were performed on the 30th, 60th, and 90th HDs. These examinations revealed decreased cellularity (plasma cell proportion) of 10% (26%), 10% (11%), and < 10% (< 4%), respectively ().\nPlatelet concentrates and packed red blood cells were transfused, and granulocyte colony-stimulating factor (G-CSF) was administered several times starting from the second HD. However, severe pancytopenia, defined as < 200/mm3 of the absolute neutrophil count, did not improve. The patient underwent allogenic peripheral blood stem cell transplantation on the 98 HD. He died of pneumonia and intracranial hemorrhage 6 months after initial presentation.