From the Guidelines
The diagnosis of Diffuse Large B-Cell Lymphoma (DLBCL) should be carried out in a reference haematopathology laboratory with expertise in morphological interpretation and the facilities to carry out the full range of phenotypic and molecular investigations, with a surgical excision biopsy being the optimal method of diagnosis. When diagnosing DLBCL, it is essential to consider the importance of a comprehensive diagnostic approach, including morphological interpretation, phenotypic, and molecular investigations, as highlighted in the ESMO clinical practice guidelines for diagnosis, treatment, and follow-up 1.
Key Considerations for Diagnosis
- A surgical excision biopsy is the preferred method for diagnosis, allowing for the assessment of nodal architecture and providing adequate material for phenotypic and molecular studies 1.
- Immunophenotypic investigations, such as immunohistochemistry (IHC) or flow cytometry, should be used to confirm the diagnosis and distinguish between different subtypes of DLBCL, including immunoblastic lymphoma, primary mediastinal B-cell lymphoma, and T-cell/histiocyte-rich large B-cell lymphoma 1.
- A suggested immunohistochemical panel for diagnosing DLBCL includes CD20, CD79a, BCL6, CD10, MYC, BCL2, Ki67, IRF4, CyclinD1, CD5, and CD23, with EBER-1 staining used to identify Epstein-Barr virus-positive DLBCL subtype of the elderly population 1.
Prognostic Factors
- The cell of origin phenotype, determined by gene expression profiling, is a significant prognostic factor in DLBCL, with tumors having a germinal center phenotype associated with a better clinical outcome than those with an activated B-cell phenotype 1.
- While immunohistochemical techniques can be used to determine the cell of origin, the prognostic effect of these results is contradictory, and it is not recommended to base clinical decisions solely on these findings 1.
From the Research
DLC (Drug Combination for Tuberculosis Treatment)
- The combination of isoniazid, rifampin, pyrazinamide, and ethambutol is a common treatment regimen for tuberculosis, as seen in the study by 2.
- This combination has been shown to be effective in treating isoniazid-resistant tuberculosis, with a high success rate and minimal side effects 2.
- The bioequivalence of this combination has been assessed in a study, which found that a fixed-dose combination tablet is bioequivalent to separate formulations of the individual drugs 3.
Pharmacokinetics and Pharmacometabonomics
- The pharmacokinetics of rifampin, isoniazid, pyrazinamide, and ethambutol have been studied in a cohort of tuberculosis patients, and several factors have been identified that affect their concentrations, including HIV infection, formulation, and patient demographics 4.
- Pharmacometabonomics has provided new insights into the metabolism and mechanism of action of these drugs, and has the potential to improve our understanding of drug resistance and treatment failure 5.
Treatment Regimens and Clinical Trials
- The World Health Organization recommends a 6-month treatment regimen for drug-susceptible tuberculosis, which includes isoniazid, rifampin, pyrazinamide, and ethambutol 6.
- Clinical trials are ongoing to evaluate the effectiveness and safety of shortened intensive treatment regimens for children with tuberculous meningitis, including a 6-month regimen with high-dose rifampicin and adjuvant anti-inflammatory therapy 6.