Objective: To evaluate the clinical characteristics, treatment response, and outcomes in patients with classical hairy cell leukemia (cHCL) and HCL variant (HCL-V). Methods: This is a retrospective case series study. Between January 2011 and December 2021, clinical data of 30 patients newly with diagnosed HCL at Peking Union Medical College Hospital were analyzed. The main outcome measures include clinical characteristics, treatment efficacy and survival. The Kaplan-Meier method was used for survival analysis. Results: Twenty-one cases of cHCL and 9 cases of HCL-v were included. The median age at diagnosis was 55.5 (range, 30-86) years, with the ratio of male to female 2.75∶1. The main clinical manifestations included fatigue in 11 cases (36.7%), abdominal distension in 7 cases (23.3%), and infection in 4 cases, while 8 cases were asymptomatic. Splenomegaly was reported in 24 cases (80.0%), including 7 (23.3%) with megalosplenia. The white blood cell count, lymphocyte count, and the proportion of peripheral hairy cells in HCL-v group were significantly higher than those in cHCL group, whereas the development of anemia, thrombocytopenia, and monocytopenia in cHCL group was more remarkable than that in HCL-v group (all P<0.05). The BRAF-V600E gene mutation was detected only in cHCL patients (11/14 vs. 0/9, P<0.001). In terms of immunophenotype, the expression of CD25, CD103, CD123 and CD200 in cHCL group (20/20, 20/20, 4/7, 7/17) were all stronger than those in HCL-v group (3/9, 7/9, 0/4, 2/8). Twenty-two patients were treated, of which 13 cases (12 cases of cHCL and 1 case of HCL-v) with cladribine, and 9 cases (4 cHCL and 5 HCL-v) with interferon. Complete remission rate and overall response rate were comparable between cladribine and interferon treatment groups (both P<0.05). The median follow-up time was 31 (range, 1-125) months, and the median overall survival (OS) of the entire group was 125 months. The 5-year OS rate in HCL-v patients represented a trend of inferior (50.0% vs. 95.0%, P=0.207). Conclusions: The clinical features of HCL are unspecific, which includes fatigue, splenomegaly and recurrent infection. The clinical features, immunophenotype, treatment response and prognosis of HCL-v are different from those of cHCL. BRAF-V600E gene mutation is suggested as a key marker for differential diagnosis. Cladribine is recommended as front-line regimen of cHCL patients with satisfactory efficacy and prognosis. Conversely, response and clinical outcome in HCL-v patients still need to be improved.
Humans ; Male ; Female ; Adult ; Middle Aged ; Aged ; Aged, 80 and over ; Leukemia, Hairy Cell/drug therapy* ; Cladribine/therapeutic use* ; Splenomegaly/drug therapy* ; Retrospective Studies ; Proto-Oncogene Proteins B-raf/therapeutic use* ; Prognosis ; Interferons/therapeutic use* ; Antineoplastic Agents/therapeutic use*

Humans ; Leukemia, Hairy Cell/diagnosis* ; Diagnosis, Differential

Hairy cell leukemia (HCL) is a rare, chronic, mature B-cell lymphoproliferative disorder accounting for 2% of all leukemias. In this paper, we would like to present our experience in the management of HCL in a financially limited setting where other diagnostic tests and chemotherapy are unavailable. The case report aims to emphasize the recognition of the distinctive morphology of hairy cells in the peripheral blood in the consideration of the initial diagnosis. A 60-year-old Filipino male was incidentally found to have anemia, thrombocytopenia and an absolute neutrophilic count below 1,000 in a pre-operative clearance for elective herniorrhaphy. Blood smear revealed atypical lymphocytes with hair like cytoplasmic projections. CT-scan of the abdomen showed splenomegaly and prominent paraaortic nodes. Flow cytometry of the bone marrow aspirate was consistent with an involvement of a Mature B cell neoplasm markers CD19, CD20, CD22 and surface immunoglobulin lambda and hairy cell leukemia markers CD11c, CD103 and CD25. He responded to six-weekly sessions of Cladribine with remission of the bone marrow and hematologic parameters. HCL is a rare type of a mature B cell neoplasm characterized by pancytopenia, splenomegaly, bone marrow fibrosis and the presence of atypical lymphoid cells with hairy projections in blood, bone marrow and spleen. Immunophenotyping express CD11c, CD103, CD123, and CD25. BRAF V600E mutation is the disease defining genetic event. Cladribine and Pentostatin are the first line of treatment. Cases of leukemia can be easily overlooked because of the mild derangement in the complete blood count. A meticulous differential review of the atypical lymphocyte, is the first step in the diagnosis of this rare disease.
Leukemia, Hairy Cell ; Cladribine ; Immunophenotyping

Humans ; Leukemia, Hairy Cell/genetics* ; MAP Kinase Kinase 1 ; Mutation

Splenic B-cell lymphomas (SBCLs) show characteristically pronounced splenomegaly without significant lymphadenopathy. Distinguishing hairy cell leukemia (HCL) from other SBCLs (splenic marginal zone lymphoma [SMZL], variant HCL [v-HCL], and splenic diffuse red pulp small B-cell lymphoma [SDRPL]) is essential to determine suitable treatments and prognoses. With advances in diagnostic modalities and therapies, splenectomy is not commonly performed, and thus diagnosis of HCL must be based on the results obtained using blood and bone marrow samples. Annexin A1 is known as the most specific marker for HCL. There has yet been no report of the assessment of annexin A1 immunostaining from Korea. In this study we analyzed samples from 13 Korean patients with SBCLs (three HCL, three v-HCL, six SMZL, and one SDRPL) from May 2001 to December 2016. Immunohistochemical analyses for annexin A1 and CD20 were performed using bone marrow sections; molecular analyses for detection of the BRAF V600E mutation were also performed. All HCL patients showed positive results for annexin A1 immunostaining and the presence of the BRAF V600E mutation, and negative results for other SBCLs. Our results confirmed the high specificity of annexin A1 and the BRAF V600E mutation as HCL markers. Molecular analysis requires expensive equipment and substantial manpower. Annexin A1 is a better alternative as an HCL marker than the BRAF V600E mutation in terms of cost-effectiveness.
Annexin A1 ; Bone Marrow ; Diagnosis ; Humans ; Korea ; Leukemia, Hairy Cell ; Lymphatic Diseases ; Lymphoma ; Lymphoma, B-Cell ; Prognosis ; Sensitivity and Specificity ; Splenectomy ; Splenomegaly

In 1993, I reported that Coxiella burnetii transforms human B cells into hairy cells (cbHCs), the first hairy cell reported outside of hairy cell leukemia (HCL). Over last few decades, advances in molecular biology have provided evidence supporting that C. burnetii induces hairiness and inhibits the apoptosis of host cells. The present review summarizes new information in support of cbHC. C. burnetii was shown to induce reorganization of the cytoskeleton and to inhibit apoptosis in host cells. Peritoneal B1a cells were found to be permissive for virulent C. burnetii Nine Mile phase I (NMI) strains in mice. C. burnetii severely impaired E-cad expression in circulating cells of Q fever patients. B-cell non-Hodgkin lymphoma was linked to C. burnetii. Mutation of BRAF V600E was pronounced in HCL, but “hairiness” was not linked to the mutation. Risk factors shared among coxiellosis and HCL in humans and animals were reported in patients with Q-fever. Accordingly, I propose that C. burnetii induces reorganization of the cytoskeleton and inhibits apoptosis as cytopathic effects that are not target cell specific. The observed hairiness in cbHC appears to be a fixed image of dynamic nature, and hairy cells in HCL are distinct among lymphoid cells in circulation. As the cytoskeleton plays key roles in maintaining cell structural integrity in health and disease, the pathophysiology of similar cytopathic effects should be addressed in other diseases, such as myopathies, B-cell dyscrasias, and autoimmune syndromes.
Animals ; Apoptosis ; B-Lymphocytes ; Coxiella burnetii ; Coxiella ; Cytoskeleton ; Humans ; Leukemia, Hairy Cell ; Lymphocytes ; Lymphoma, Non-Hodgkin ; Mice ; Molecular Biology ; Muscular Diseases ; Q Fever ; Risk Factors

No abstract available.
Leukemia, Hairy Cell ; Multiple Myeloma ; Plasma Cells ; Plasma

No abstract available.
Leukemia, Hairy Cell* ; Leukemia, Lymphocytic, Chronic, B-Cell*

Hairy cell leukemia (HCL) is a rare chronic B cell leukemia morphologically characterized by cells with an abundant cytoplasm and hair-like projections that can be found in the peripheral blood and bone marrow. The treatment for HCL is splenectomy or chemotherapy with the purine analogs pentostatin and cladribine. However, patients continue to relapse. Retreatment with the same or alternate purine analogs produces lower response rates and a shorter duration of response. Fludarabine is another purine analog widely used in treating indolent lymphoid cancers, often in combination with rituximab. Here, we report a case of HCL variant in a 60-year-old man who experienced multiple relapses after splenectomy and retreatment with cladribine. The patient was then treated with fludarabine and rituximab combination chemotherapy. After the treatment, he achieved complete remission that continued for 35 months.
Bone Marrow ; Cladribine ; Cytoplasm ; Drug Therapy ; Drug Therapy, Combination ; Humans ; Leukemia, B-Cell ; Leukemia, Hairy Cell ; Middle Aged ; Pentostatin ; Recurrence ; Retreatment ; Rituximab ; Splenectomy

Objective: To investigate the curative effect of hairy cell leukemia by clatabine. Methods: The clinical data of 24 patients with hairy cell leukemia treated by cladribine from November 2006 to October 2017 were analyzed retrospectively, then the curative effect and adverse drug reaction were analyzed. Results: ① A total of 24 patients including 22 male and 2 female, and the median age was 49.5 years (range 33 to 76) at diagnosis. There were 20 patients with of splenomegaly (4 patients with mild splenomegaly, 4 moderate splenomegaly, and 12 massive splenomegaly), 3 patients with enlargement of lymph nodes, and 1 patients who had undergone splenectomy. Five patients were pancytopenia, 15 were cytopenia in 2 lineages, and 4 patients were cytopenia only in one lineage. The median ratio of HCL cells detected by flow cytometry in bone marrow was 21.79% (0.69%-68.96%). BRAF mutation was detected in 15 patients by first generation or next generation sequencing technology. ② Among 24 patients, 20 were treated with cladribine alone (one course in 19 patients, 2 courses in 1 patient), and 4 patients were treated with cladribine combined with rituximab (one course in 3 patients, 2 courses in 1 patient). Excepting 5 patients whose follow-up time was not reaching 6 months, 19 patients were evaluated for efficacy in 6-12 months after treatment: 9 patients obtained CR, 9 obtained unconfirmed CR (Cru), the other 1 obtained PR, the CR/CRu rate was 94.7%, the overall response rate (ORR) was 100.0%. ③ All the 24 patients appeared 2-4 grade hematological adverse reactions after cladribine treatment, which were mainly grade 3/4 neutropenia (66.67%) and grade 3/4 thrombocytopenia (29.2%). All the adverse reactions were controlled or recovered spontaneously. ④ After the median follow-up time of 15 (3-133) months, no progression, recurrence or death occurred in the patients. Both median OS and PFS were not reached. Conclusion: This study suggests that treatment of HCL with cladribine has high response rate, controllable adverse reactions and the good prognosis.
Adult ; Aged ; Antineoplastic Agents/therapeutic use* ; Cladribine/therapeutic use* ; Female ; Humans ; Leukemia, Hairy Cell/drug therapy* ; Male ; Middle Aged ; Retrospective Studies ; Rituximab