Neoehrlichia mikurensis-An emerging opportunistic tick-borne infection in immunosuppressed patients.

BACKGROUND: Neoehrlichia mikurensis (N. mikurensis) is a newly discovered tick-borne pathogen that can inflict life-threatening illness in immunocompromised patients. N. mikurensis infection is only detectable by polymerase chain reaction (PCR)-based methodologies. We describe three distinct clinical manifestations of N. mikurensis infection (neoehrlichiosis) in Danish patients receiving B-lymphocyte-depleting therapy, rituximab, for underlying hematological, rheumatological, or neurological disorders. All three patients went through a protracted pre-diagnostic period. METHODS: N. mikurensis DNA was detected and confirmed using two methods. Blood was tested by specific real-time PCR targeting the groEL gene and by 16S and 18S profiling followed by sequencing. Bone marrow was analyzed by 16S and 18S profiling. RESULTS: N. mikurensis was detected in blood samples in all three cases and in bone marrow from one of the three. The severity of the symptoms ranged from prolonged fever lasting more than 6 months to life-threatening hyperinflammation in the form of hemophagocytic lymphohistiocytosis (HLH). Interestingly, all patients presented with splenomegaly and two with hepatomegaly. After starting doxycycline therapy, symptoms were relieved within a few days, and biochemistry and organomegaly quickly normalized. CONCLUSION: We present three Danish patients recognized by the same clinician over a period of 6 months, strongly suggesting that many cases are going unrecognized. Second, we describe the first case of N. mikurensis-induced HLH and emphasize the potential severity of undetected neoehrlichiosis.

PD-L1 expression is low in large B-cell lymphoma with MYC or double-hit translocation.

In large B-cell lymphoma (LBCL), MYC translocation and MYC/BCL2 or MYC/BCL6 double hit (DH) are associated with poor prognosis, and there is an unmet need for novel treatment targets in this patient group. Treatments targeting the PD-L1/PD-1 pathway are still poorly elucidated in LBCL. PD-L1 expression might predict response to treatment targeting the PD-L1/PD-1 pathway. We therefore investigated the relationship between PD-L1 protein and mRNA expression levels and MYC and DH translocation in LBCL. We detected MYC, BCL2, and BCL6 translocation by fluorescent in situ hybridization in tissue samples from 130 patients randomly selected from two cohorts of patients with LBCL: 49 patients with MYC translocation of whom 36 had DH and 81 without MYC translocation. PD-L1 protein expression was detected by immunohistochemistry (IHC) in tissue samples from 77 patients and PD-L1 mRNA expression by next-generation RNA sequencing (NGS) in another 77 patients. Twenty-four patients overlapped, ie, were analysed with both IHC and NGS. Nonparametric tests were performed to evaluate intergroup differences. PD-L1 protein expression level was significantly lower in patients with MYC (n = 42, median = 3.3%, interquartile range [IQR] 0.0-10.8) or DH translocations (n = 31, median = 3.3%, IQR 0.0-10.0) compared with patients with no MYC (n = 35, median = 16.7%, IQR 3.3-30.0) or no DH translocations (n = 46, 13.3%, IQR 2.5-30.0), P = .004 and P ≤ .001, respectively. PD-L1 mRNA expression was also significantly lower in patients with MYC or DH translocations, P = .001 and P = .006, respectively. Higher PD-L1 protein and mRNA expression levels were associated with non-germinal centre (GC) type compared with germinal centre B-cell (GCB)-type diffuse LBCL (DLBCL), P = .004 and P = .002, respectively. In conclusion, we report an association between low PD-L1 expression and MYC and DH translocation in patients with LBCL. Our findings may indicate that patients with MYC or DH translocation may benefit less from treatment with PD-L1/PD-1-inhibitors compared with patients without these translocations. This should be evaluated in larger, prospective, consecutive trials.

Stratification by MYC expression has prognostic impact in MYC translocated B-cell lymphoma-Identifies a subgroup of patients with poor outcome.

OBJECTIVE: In patients with large B-cell lymphoma (LBCL) according to WHO, the prognostic significance of MYC translocation is still not sufficiently clarified. We therefore aimed to investigate whether prognostication could be improved in patients with MYC translocation positive LBCL by additional stratification according to MYC and BCL2 protein expression levels or MYC translocation partner gene as well as concurrent BCL2 and/or BCL6 translocation (DH). METHODS: From an unselected consecutive cohort of >600 patients with LBCL investigated with fluorescent in situ hybridization (FISH), 64 patients were diagnosed with MYC translocation positive LBCL and included in the study. They were further investigated for supplemental translocations with FISH and MYC and BCL2 protein expression with immunohistochemistry (IHC). RESULTS: MYC expression >75% was associated with both reduced progression-free survival (PFS) and overall survival (OS) (PFS: HR 6.8 (95% CI 1.5-31), P = 0.004. OS: HR 4.3 (95% CI 0.9-21), P = 0.05). Immunoglobulin (IG) MYC translocation partner gene was related to high MYC protein expression (P = 0.047) but was not prognostic for PFS (P = 0.8) or OS (P = 0.6). DH did not confer a worse outcome compared to MYC single hit (SH). These findings were confirmed in a comparable, independent validation cohort of 28 patients with MYC translocation positive LBCL. All patients included in the survival analyses were treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) or R-CHOEP (R-CHOP + etoposide). CONCLUSION: These findings suggest that in patients with LBCL stratification by MYC protein expression level significantly improves the prognostic impact associated with MYC translocation.

Atypical presentation of γ/δ mycosis fungoides with an unusual phenotype and SOCS1 mutation.

Mycosis fungoides is the most frequent subtype of primary cutaneous T-cell lymphomas. The diagnosis is based on a thorough clinic-pathologic correlation, which can, especially in early-stage disease, be challenging due to similarities with several benign skin disorders such as psoriasis and atopic dermatitis. Here, we present a case of an 81-year-old man with a 20-year-long medical history of skin problems treated as psoriasis with limited effect. Since December 2021, the patient experienced worsening of his skin symptoms with rapidly growing tumors and widespread patches and plaques. Positron emission tomography/computed tomography evaluation revealed markedly metabolic activity related to the skin tumors and increased FDG uptake in several retroperitoneal lymph nodes. Histological assessment of skin biopsies demonstrated a highly proliferative T-cell lymphoma with a γ/δ+ and CD8+ cytotoxic phenotype. The morphology of the tumor cells appeared blastic with an abnormal immunephenotype CD3+, CD2-, CD5dim, CD4-, CD8+, CD56-, and CD30-. Next-generation sequencing detected a likely pathogenic SOCS1 mutation with an allele frequency of 72% as well as a STAT3 variant of unknown significance. This case highlights the diagnostic complexity of an indolent skin lymphoma evolving into an aggressive cytotoxic lymphoma.

Localized blastic plasmacytoid dendritic cell neoplasm associated with progressive clonal hematopoiesis and myelodysplastic syndrome.

Clonal hematopoiesis is highly prevalent in elderly patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN), and around 20% of BPDCN patients have an associated myeloid malignancy. We present a patient with localized BPDCN and concomitant myelodysplastic syndrome (MDS), previously followed for several years due to clonal cytopenia of unknown significance. Compared targeted next-generation sequencing (NGS) of the skin tumor and sequential bone marrow samples showed shared variants in ASXL1 and TET2 with a de novo NRAS variant in both BPDCN and MDS compared to preceding bone marrow samples. These findings illustrate a shared clonal origin of BPDCN and MDS resulting from progressive clonal hematopoiesis.

World Health Organization-defined classification of myeloproliferative neoplasms: morphological reproducibility and clinical correlations--the Danish experience.

We examined inter- and intraobserver reproducibility and concordance between histological diagnosis and independently collected clinical findings in a large series of patients with the major subtypes of myeloproliferative neoplasms (MPNs) and controls. Seven hematopathologists reviewed 272 bone marrow biopsies including 43 controls. Diagnoses were determined according to the 2008 criteria of the World Health Organization (WHO). The participants were blinded to all clinical data except patient age. After initial evaluation all hematopathologists participated in a 3-day meeting with a leading clinician chaired by an expert hematopathologists. In cases with lack of consensus on fiber grading (n = 57), a new evaluation was performed. In cases with discordance on morphological diagnosis (n = 129), an additional nonblinded evaluation taking clinical data into consideration was carried out. For remaining cases with a lack of concordance between morphological diagnosis and clinical diagnosis (n = 33), a similar nonblinded evaluation was performed. Consensus on final histological diagnosis and concordance with clinical diagnosis were determined. Blinded histological evaluation resulted in a 53% consensus rate. After re-evaluation of fiber content, consensus was reached in 60% of cases. Adding clinical data increased the histological consensus to 83%. For cases with a histological consensus, we found a concordance of 71% with the clinician's diagnoses. This is the first study to present a larger cohort of MPN patients mimicking the diagnostic challenges that hematopathologists face in their daily practice. The results support the postulates of the WHO that both morphological and clinical findings are essential for a valid diagnosis

Linear IgA/IgG bullous dermatosis successfully treated with omalizumab: A case report.

Linear IgA/IgG bullous dermatosis (LAGBD) is a rare, autoimmune blistering skin disease. We report a case of LAGBD in a 70-year-old woman. All common treatments were discontinued due to side effects or lack of treatment response. The patient was successfully treated with omalizumab which cleared her lesions after three months.

Vaccination against PD-L1 with IO103 a Novel Immune Modulatory Vaccine in Basal Cell Carcinoma: A Phase IIa Study.

Antitumor activity of immune checkpoint blocking antibodies against programmed death 1 (PD-1) in basal cell carcinoma (BCC) has been described. IO103 is a peptide vaccine against the major PD-1 ligand PD-L1. A phase IIa study of vaccination with IO103 and Montanide adjuvant was conducted in patients with resectable BCC (NCT03714529). Vaccinations were given six times every 2 weeks (q2w), followed by three vaccines q4w in responders. Primary endpoints were clinical responses of target tumors, change in target tumor size and immune responses to the vaccine. Secondary endpoint was safety. One tumor per patient was designated target tumor and biopsied twice during the course of vaccination. Synchronous non-target BCCs were not biopsied during vaccinations. Ten patients were vaccinated (six patients received six vaccinations and four patients received nine vaccinations). A partial response (PR) was seen in two target tumors. Two complete responses (CR) and one PR were observed in eight non-target tumors in four patients. No tumors progressed. Related adverse events were grade 1 and reversible. Immune responses against IO103 were induced in blood samples from nine of ten and skin-infiltrating lymphocytes from five of the nine patients. The regressions seen in non-target tumors suggest that IO103 may be effective against a subtype of BCC.

Real world data on young patients with high-risk diffuse large B-cell lymphoma treated with R-CHOP or R-CHOEP - MYC, BCL2 and BCL6 as prognostic biomarkers.

BACKGROUND: Double expression of MYC and BCL2 proteins (DE) and double-hit MYC+BCL2/BCL6 translocations (DH) were established as important biomarkers in patients with diffuse large B-cell lymphoma (DLBCL) by the 2016 revision of the World Health Organization classification of lymphoid neoplasms. Whether this applies to the subgroup of young patients with high risk DLBCL is not known. We previously found that in a uniform retrospective population-based cohort of patients aged 18-60 years with high-risk DLBCL, the addition of etoposide to R-CHOP chemotherapy (R-CHOEP) resulted in improved survival mainly in patients with germinal center B-cell like (GCB) immunophenotype. The aim of this study was to investigate the prognostic and predictive value of DE and DH in this patient cohort. METHODS: Data on all young Danish patients diagnosed with de novo high-risk DLBCL 2004-2008 and treated with R-CHOP or R-CHOEP were obtained from the Danish Lymphoma database (n = 159). Tumor samples were available from 103 patients. MYC and BCL2 proteins were analyzed with quantitative immunohistochemistry (IHC) using different cut off values. MYC-, BCL2- and BCL6-translocations were examined with fluorescent in situ hybridization (FISH). RESULTS: DE with MYC>75% and BCL2>85% was an independent negative prognostic marker of progression free survival (PFS) in patients treated with R-CHOP but not R-CHOEP (p<0.001), also after exclusion of patients with DH. A predictive effect of DE for response (PFS) to R-CHOEP vs. R-CHOP was almost significant (p = 0.07). DH was not prognostic in this patient cohort. CONCLUSION: In young patients with high-risk DLBCL, treatment with R-CHOEP may overcome the negative prognostic impact of DE observed in patients treated with R-CHOP.

Successful Treatment of Posttransplant EBV-Associated Lymphoma and Plasmacytoma Solely Localized to the CNS.

Two patients with diabetic nephropathy were diagnosed with primary central nervous system posttransplant Epstein-Barr-virus-associated lymphoproliferative disorder (PTLD) 3 years after renal transplantation. The histological diagnoses of the isolated brain tumors were diffuse large B-cell lymphoma and plasmacytoma. Considerable co-morbidity precluded intensive chemotherapy. The first patient with lymphoid CD20+ PTLD had a partial resection of her tumor performed. She was treated with 4 weekly doses of rituximab, ganciclovir and prednisolone; the posttransplant immune suppression (tacrolimus) was reduced. After 4 weeks of treatment a magnetic resonance imaging (MRI) demonstrated complete regression of the CNS lesion. The patient continues to receive rituximab (every second month), valgangciclovir and low-dose prednisolone. Twenty-two months after initiation of therapy, she is still in complete remission. The second patient was only treated with craniospinal irradiation involving the medulla to the second cervical vertebra and valgangciclovir. Moreover, the posttransplant immune suppression was reduced. A new MRI two months after initiation of therapy showed a complete regression of the lesions in the CNS; this was again demonstrated by a MRI after 19 months. These 2 cases illustrate interesting alternative treatments of PTLD. To our knowledge, an EBV-associated PTLD of plasmacytic origin isolated to the CNS has never been described before.

[Mycobacterium marinum is difficult to diagnose]. / Mycobacterium marinum kan være vanskelig at diagnosticere.

The diagnosis of cutaneous Mycobacterium marinum infection is often delayed for months after presentation. In this case the diagnosis and correct treatment was delayed for ten months resulting in possible irreversible damage to the patient's infected finger. The main reason for the delay is lack of knowledge of the mycobacterium.

[Burkitt lymphoma is a highly malign tumour with a doubling time of twenty-four hours]. / Burkitts lymfom er en højmalign tumor med en fordoblingstid på et døgn.

The treatment results for patients with Burkitt lymphoma have improved markedly over the past 20 years. Focus on the rapid doubling time of the lymphoma, and the frequent involvement of the central nervous system, have led to effective intensive chemotherapy regimens, where several of the drugs cross the blood-brain barrier. The overall survival is now 65-80% even when patients have advanced disease at the time of diagnosis. However, the condition and its complications such as tumour lysis syndrome are acute life threatening, and a quick diagnosis and proper management of complications are essential for the prognosis.

[Highly malignant B cell lymphoma as penile tumour]. / Højmalignt B-celle-lymfom som tumor penis.

On suspicion of carcinoma, a male with a tumour on the penis was partially amputated without prior biopsy. Histopathology showed lymphoma. Later another lymphoma was discovered and chemotherapy was commenced. Three years later the patient died of an unrelated cause without signs of recurrence. If the patient's disease had been correctly diagnosed prior to treatment, chemotherapy alone or possibly combined with less mutilating surgery would probably have proven sufficient. In treating patients with tumours, it is important to obtain a histological diagnosis prior to choosing treatment.