Received Feb 25, 2026
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| RVX | ROTAVIRUS (NO BRAND NAME) | UNKNOWN MANUFACTURER | UNK | UNK | — |
transient monoclonal plasma cell aberrancy following respiratory syncytial virus (RSV) vaccination; leukocytosis; This serious case was reported in a literature article and described the occurrence of plasma cells increased in a 77-year-old female patient who received RSVPreF3 adjuvanted (RSV vaccine) for prophylaxis. Literature Reference. The patient's past medical history included chemotherapy (1 year prior) and surgery. Concurrent medical conditions included ovarian cancer stage iv, brain metastases, hypertension, hyperlipidemia, anxiety, polyneuropathy, lymphadenopathy inguinal (increasing diaphragmatic, retroperitoneal pelvic) and secondary malignant neoplasm of ovary. On an unknown date, the patient received RSV vaccine. On an unknown date, 4 days after receiving RSV vaccine, the patient experienced plasma cells increased (Verbatim: transient monoclonal plasma cell aberrancy following respiratory syncytial virus (RSV) vaccination) (serious criteria hospitalization) and leukocytosis (Verbatim: leukocytosis) (serious criteria hospitalization). The outcome of the plasma cells increased and leukocytosis were resolved. The reporter considered the plasma cells increased and leukocytosis to be related to RSV vaccine. The company considered the plasma cells increased and leukocytosis to be unrelated to RSV vaccine. Additional Information: GSK received date: 19-FEB-2026 The patient with a history of stage IVa high-grade serous ovarian cancer complicated by brain metastasis, status post resection and previous treatment, hypertension, hyperlipidemia, anxiety, and drug-induced polyneuropathy, who initially presented for preoperative labs prior to planned port placement. The patient obtains oncology care at an external institution and was referred to author institution for port placement after surveillance imaging showed increasing diaphragmatic, retroperitoneal pelvic, and right inguinal adenopathy concerning for recurrence of malignancy. The patient last received chemotherapy about 1 year prior. Patient was noted to have received the RSV vaccine 4 days prior to presentation for preoperative labs. During preoperative laboratory testing, the patient was found to have leukocytosis (white blood cell count of 20.6 x10(9)/ L). Peripheral blood smear demonstrated 22 percent atypical plasma cells with associated red blood cell rouleaux formation. Flow cytometric analysis of peripheral blood revealed an increased population (22.4 percent) of monoclonal plasma cells expressing CD19, CD27, CD38, CD81, and CD138, and lacking expression of CD20, CD56, and CD117, with cytoplasmic lambda light chain restriction (22,482 plasma cell events with cytoplasmic kappa:lambda ratio of 0.05). The presence of surface light chain expression may suggest that this population represents a spectrum of differentiation, ranging from plasmacytoid B-cells to more mature plasma cells, as fully differentiated plasma cells typically lack surface immunoglobulin expression. These findings were concerning for a plasma cell neoplasm. Aside from this population of atypical plasma cells, no aberrant B- or T-cell populations were identified (B-cell surface kappa:lambda ratio of 2.5). Patient completed outpatient infectious work-up including viral respiratory pathogens, which were reportedly negative, but records were not accessible in authors electronic medical records.Patient was admitted 5 days later for evaluation of suspected plasma cell neoplasm. On admission, the patient's vitals were stable, and patient was asymptomatic. Examination showed lower extremity edema and post-surgical changes but was otherwise unremarkable. Patients admission labs showed leukocytosis (WBC 11.74), with peripheral blood smear negative for the previously observed population of atypical plasma cells and Rouleaux formation. Serum and urine protein electrophoresis showed normal protein profiles without an M-spike observed. The patient's kappa/lambda light chain ratio was normal (1.22) by serum immunofixation electrophoresis (SIFE) test. Repeat flow cytometry showed a mixture of B-cells (surface kappa:lambda = 2.3) and T-cells, with lack of support for aberrant plasma cell population (29 polytypic plasma cell events showing cytoplasmic kappa:lambda ratio of 1.5). Immunofixation showed polytypic IgA at the upper limit of normal but was otherwise normal. Blood cultures collected at admission returned negative. Hepatitis serologies and HIV testing were negative. Given the differential findings, extensive investigation was carried out to rule out the possibility of blood sample error or contamination, which confirmed both the original and repeat samples as belonging to the patient. Given absent serological evidence of multiple myeloma (MM), bone marrow biopsy was deferred. The patient underwent port placement and was discharged in stable condition for lymph node biopsy at an external oncology institution with plans to start single-agent carboplatin for recurrence of metastatic ovarian carcinoma. This case was the first report of a transient population of peripherally circulating monoclonal plasma cells following RSV vaccination. In the case of patient, further evaluation of leukocytosis on preoperative labs led to concern for a plasma cell neoplastic process due to the observation of elevated levels of circulating monoclonal plasma cells in peripheral blood. This case highlighted a rare and previously undocumented immune response following RSV vaccination, characterized by a transient population of peripherally circulating monoclonal plasma cells. The observation of a monoclonal plasma cell population post-vaccination, without accompanying serological or clinical evidence of a plasma cell neoplasm, suggested that the immune response triggered by the RSV vaccine may mimic, albeit transiently, features typically associated with plasma cell disorders. This article is not available for regulatory reporting purpose due to copyright restriction.; Sender's Comments: A case of Plasma cells increased and Leukocytosis, 4 days after receiving vaccine RSV vaccine in a 77-year-old female patient. Report is inconsistent with causal relation to the vaccine product, considering absence of biological plausibility and alternative risk factors (suspected plasma cell neoplasm, h/o chemotherapy, concurrent ovarian cancer sate IV, brain mestastases and secondary malignant neoplasm of ovary).
Anxiety; Brain metastases; Hyperlipidemia; Hypertension; Lymphadenopathy inguinal (increasing diaphragmatic, retroperitoneal pelvic); Ovarian cancer stage IV; Polyneuropathy; Secondary malignant neoplasm of ovary
Medical History/Concurrent Conditions: Chemotherapy (1 year prior); Surgery
Test Name: Blood cultures; Result Unstructured Data: (Test Result:negative,Unit:unknown,Normal Low:,Normal High:); Test Name: serum protein electrophoresis; Result Unstructured Data: (Test Result:normal protein profiles without an M-spike observe,Unit:unknown,Normal Low:,Normal High:); Test Name: Hepatitis serology; Result Unstructured Data: (Test Result:negative,Unit:unknown,Normal Low:,Normal High:); Test Name: HIV testing; Result Unstructured Data: (Test Result:negative,Unit:unknown,Normal Low:,Normal High:); Test Name: Immunofixation; Result Unstructured Data: (Test Result:polytypic IgA at the upper limit of normal,Unit:unknown,Normal Low:,Normal High:); Test Name: kappa/lambda light chain ratio; Result Unstructured Data: (Test Result:1.22,Unit:unknown,Normal Low:,Normal High:) serum immunofixation electrophoresis (SIFE) test; Test Name: kappa/lambda light chain ratio; Result Unstructured Data: (Test Result:2.3,Unit:unknown,Normal Low:,Normal High:); Test Name: kappa/lambda light chain ratio; Result Unstructured Data: (Test Result:1.5,Unit:unknown,Normal Low:,Normal High:); Test Name: viral respiratory pathogen; Result Unstructured Data: (Test Result:negative,Unit:unknown,Normal Low:,Normal High:); Test Name: vitals; Result Unstructured Data: (Test Result:stable,Unit:unknown,Normal Low:,Normal High:); Test Name: white blood cell count; Result Unstructured Data: (Test Result:20.6,Unit:10*9/uL,Normal Low:,Normal High:); Test Name: white blood cell count; Result Unstructured Data: (Test Result:11.74,Unit:10*9/uL,Normal Low:,Normal High:); Comments: Peripheral blood smear demonstrated 22 percent atypical plasma cells with associated red blood cell rouleaux formation. Flow cytometric analysis of peripheral blood revealed an increased population (22.4 percent) of monoclonal plasma cells expressing CD19, CD27, CD38, CD81, and CD138, and lacking expression of CD20, CD56, and CD117, with cytoplasmic lambda light chain restriction (22,482 plasma cell events with cytoplasmic kappa:lambda ratio of 0.05). The presence of surface light chain expression may suggest that this population represents a spectrum of differentiation, ranging from plasmacytoid B-cells to more mature plasma cells, as fully differentiated plasma cells typically lack surface immunoglobulin expression. These findings were concerning for a plasma cell neoplasm. Aside from this population of atypical plasma cells, no aberrant B- or T-cell populations were identified (B-cell surface kappa:lambda ratio of 2.5. Examination showed lower extremity edema and post-surgical changes but was otherwise unremarkable. Peripheral blood smear negative for the previously observed population of atypical plasma cells and Rouleaux formation. urine protein electrophoresis showed normal protein profiles without an M-spike observed. Repeat flow cytometry showed a mixture of B-cells (surface kappa:lambda = 2.3) and T-cells, with lack of support for aberrant plasma cell population (29 polytypic plasma cell events showing cytoplasmic kappa:lambda ratio of 1.5). Given the differential findings, extensive investigation was carried out to rule out the possibility of blood sample error or contamination, which confirmed both the original and repeat samples as belonging to the patient. Given absent serological evidence of multiple myeloma (MM), bone marrow biopsy was deferred. After surveillance imaging showed increasing diaphragmatic, retroperitoneal pelvic, and right inguinal adenopathy concerning for recurrence of malignancy