Tuberculosis-associated IgA nephropathy

Disseminated Mycobacterium Tuberculosis and IgA Nephropathy

Mycobacterium tuberculosis (MTB) is an under-recognised cause of genitourinary disease. IgA nephropathy (IgAN), a leading cause of glomerulonephritis worldwide, has been described as a rare consequence of disseminated MTB infection. In this case report, we present the first case of MTB associated IgAN in Africa. Finding IgAN on kidney biopsy in an MTB endemic area should prompt a thorough investigation for MTB to increase the chance of remission of IgAN and prevent inappropriate use of immunosuppression.

A risk prediction model for acute kidney injury in patients with pulmonary tuberculosis during anti-tuberculosis treatment

Background

Acute kidney injury (AKI) is not a rare complication during anti-tuberculosis treatment in some patients with pulmonary tuberculosis (PTB). We aimed to develop a risk prediction model for early recognition of patients with PTB at high risk for AKI during anti-TB treatment.

Methods

This retrospective cohort study assessed the clinical baseline, and laboratory test data of 315 inpatients with active PTB who were screened for predictive factors from January 2019 to June 2020. The elements were analyzed by logistic regression analysis. A nomogram was established by the results of the logistic regression analysis. The prediction model discrimination and calibration were evaluated by the concordance index (C-index), ROC curve, and Hosmer-Lemeshow analysis.

Results

A total of 315 patients with PTB were enrolled (67 patients with AKI and 248 patients without AKI). Seven factors, including microalbuminuria, hematuria, cystatin-C (CYS-C), albumin (ALB), creatinine-based estimated glomerular filtration rates (eGFRs), body mass index (BMI), and CA-125 were acquired to develop the predictive model. According to the logistic regression, microalbuminuria (OR = 3.038, 95%CI 1.168–7.904), hematuria (OR = 3.656, 95%CI 1.325–10.083), CYS-C (OR = 4.416, 95%CI 2.296–8.491), and CA-125 (OR = 3.93, 95%CI 1.436–10.756) were risk parameter, while ALB (OR = 0.741, 95%CI 0.650–0.844) was protective parameter. The nomogram demonstrated good prediction in estimating AKI (C-index= 0.967, AUC = 0.967, 95%CI (0.941–0.984), sensitivity = 91.04%, specificity = 93.95%, Hosmer-Lemeshow analysis SD = 0.00054, and quantile of absolute error = 0.049).

Conclusions

Microalbuminuria, hematuria, ALB reduction, elevated CYS-C, and CA-125 are predictive factors for the development of AKI in patients with PTB during anti-TB treatments. The predictive nomogram based on five predictive factors is achieved good risk prediction for AKI during anti-TB treatments.

IgA Vasculitis Complicated by Both CMV Reactivation and Tuberculosis

Immunoglobulin A (IgA) vasculitis is the most common systemic vasculitis in the pediatric population. We present the case of a patient with IgA vasculitis with nephritis who developed cytomegalovirus (CMV) infection followed by Mycobacterium tuberculosis infection. In the literature, there are a few cases of IgA nephropathy accompanied by reactivation of CMV or tuberculosis. To the best of our knowledge, this is the first reported case of IgA vasculitis complicated by both CMV reactivation and tuberculosis. It is important to detect infections in patients with IgA vasculitis because they can induce and exacerbate the symptoms of the disease. Effective antimicrobial treatment facilitates the management of proteinuria and slows down the decline of renal function. Immunosuppressive therapy is a risk factor for reactivation of latent infections and makes patients more susceptible to its generalized and complicated course. This can be prevented by actively screening for hidden sites of infection.

Mesangiocapillary glomerulonephritis complicating pulmonary tuberculosis

Glomerulonephritis in tuberculosis may be a direct manifestation of renal infection or a result of immune-complex deposition complicating extra-renal infection, such as in pulmonary tuberculosis. A 17-year-old adolescent boy from Somalia was found to have pulmonary tuberculosis during routine health screening performed on entering Malta, with computed tomography of the chest showing scarring and calcification of the left upper lobe, left lower lobe consolidation, and a small left-sided pleural effusion. Five days after starting anti-tuberculous therapy, he developed lower limb and sacral oedema: urinary albumin: creatinine ratio was > 400 µg albumin/mg creatinine, and 24-h urinary protein showed nephrotic-range proteinuria of 4.963 g/day. In view of worsening lower limb, sacral and periorbital oedema and ascites, he was started on oral prednisolone, omeprazole and penicillin V prophylaxis. As heavy proteinuria persisted, a renal biopsy was performed after 8 days of prednisolone treatment, which confirmed the presence of mesangiocapillary glomerulonephritis (MCGN), with electron microscopy showing effacement of the podocytes, with hypercellularity and subendothelial immune deposits, confirming an immune-mediated pathophysiology. Ziehl-Neelsen staining did not reveal acid-fast organisms. The patient received a total of 3 weeks of oral prednisolone with subsequent tailing doses, 2 months of pyrazinamide and ethambutol and 6 months of rifampicin and isoniazid with complete resolution of his clinical and radiological signs, though heavy proteinuria persisted, so he was commenced on oral enalapril. This case highlights the potential association of MCGN with tuberculosis in adolescence. Timely recognition and treatment can prevent progression to chronic kidney disease.

The coexistence of IgA vasculitis and tuberculosis: a case-based review

Immunoglobulin (Ig) A vasculitis (IgAV), formerly known as Henoch-Schonlein purpura (HSP), is a relatively uncommon form of vasculitis primarily targeting the skin, gastrointestinal system, and the kidneys. Although the pathogenesis has not yet been well identified, several triggering factors, such as infections, drugs, have been implicated in the development of IgAV. Tuberculosis (TB), albeit rare, may precipitate IgAV. Herein, we have presented a case manifested by purpuric skin rash and proteinuria 6 weeks following diagnosis of pulmonary tuberculosis while receiving anti-TB drugs. The case was diagnosed as having active tuberculosis and TB-related IgA vasculitis with multi-organ involvement. In this case-based review, we recruited cases with TB-related Ig A vasculitis from the literature and discussed the features of tuberculosis that mimic vasculitides and vice versa. We also discussed the difficulties in diagnosis and the therapeutic approach in the light of the literature.

An Inflammatory Story: Antibodies in Tuberculosis Comorbidities

Mycobacterium tuberculosis (Mtb) resides in a quarter of the world's population and is the causative agent for tuberculosis (TB), the most common infectious reason of death in humans today. Although cellular immunity has been firmly established in the control of Mtb, there is growing evidence that antibodies may also modulate the infection. More specifically, certain antibody features are associated with inflammation and are divergent in different states of human infection and disease. Importantly, TB impacts not just the healthy but also those with chronic conditions. While HIV represents the quintessential comorbid condition for TB, recent epidemiological evidence shows that additional chronic conditions such as diabetes and kidney disease are rising. In fact, the prevalence of diabetes as a comorbid TB condition is now higher than that of HIV. These chronic diseases are themselves independently associated with pro-inflammatory immune states that encompass antibody profiles. This review discusses isotypes, subclasses, post-translational modifications and Fc-mediated functions of antibodies in TB infection and in the comorbid chronic conditions of HIV, diabetes, and kidney diseases. We propose that inflammatory antibody profiles, which are a marker of active TB, may be an important biomarker for detection of TB disease progression within comorbid individuals. We highlight the need for future studies to determine which inflammatory antibody profiles are the consequences of comorbidities and which may potentially contribute to TB reactivation.

A rare association of Mycobacterium tuberculosis infection of kidney and urinary tract with immunoglobulin A nephropathy

Mycobacterium tuberculosis(MTB)-related secondary immunoglobulin A (IgA) nephropathy is reported in a 72-year-old male patient. The patient was diagnosed to have MTB infection of the kidney and genitourinary tract which was diagnosed by the demonstration of the organism by GeneXpert Ultra and culture. Concurrent kidney biopsy showed IgA nephropathy. The patient responded to urethral double-J stenting and four-drug antituberculous therapy with improvement of kidney function and resolution of MTB. IgA nephropathy can present as primary glomerulonephritis or secondary to MTB infection.