Idiopathic CD4 lymphocytopenia and opportunistic infection — an update: Table 1

Progressive multifocal leukoencephalopathy secondary to idiopathic CD4 lymphocytopenia treated with pembrolizumab

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating disease due to a lytic infection of oligodendrocytes caused by John Cunningham polyoma virus (JCV) infection. Idiopathic CD4+ T-cell lymphocytopenia (ICL) is a very rare cause of PML.

METHODS

We present an individual with PML secondary to ICL treated with 3 doses of pembrolizumab, a Programmed-Death-1 Immune Checkpoint Inhibitor following with complete resolution of symptoms and conduct a review of the literature.

CONCLUSION

This report illustrates the objective clinical and radiological improvement in a patient with PML due to ICL and suggests further study of immune checkpoint inhibitors as potential treatment for patients with PML.

Acute Cryptococcal Meningitis in a Patient With Idiopathic CD4 Lymphocytopenia: A Rare Clinical Entity

Cryptococcal meningitis is a known cause of opportunistic infection in immunocompromised patients, especially those with AIDS. Very few cases exist in literature where cryptococcal meningitis is seen in patients without evidence of HIV infection. Here, we describe a case of an elderly woman presenting with clinical features of meningitis. Our patient tested positive for cryptococcal antigen (CRAg) in the CSF and growth of Cryptococcus neoformans was obtained in CSF culture. Further laboratory investigations revealed CD4 lymphocytopenia (233 cells/μl) in the absence of HIV infection. When we checked the CD4 count, beyond a period of six weeks, it was reported to be low, which confirmed our diagnosis of idiopathic CD4 lymphocytopenia (ICL). She was successfully treated with amphotericin B along with flucytosine for two weeks and discharged on maintenance antifungal therapy for eight weeks. This case emphasizes the need to maintain a high index of suspicion and consider the possibility of opportunistic infections even in the absence of HIV infection for timely diagnosis and treatment.

Idiopathic CD4+ T lymphocytopenia: A case report

Idiopathic CD4+ T lymphocytopenia (ICL) is a very rare immunodeficiency syndrome with an unexplained depletion of CD4+ T lymphocytes and no evidence of Human Immunodeficiency Virus (HIV) infection. Here we report a 29-year-old male patient who had severe ulcerative colitis with low level CD4+ count of 254 cells/mm³, and had no evidence of HIV or Human T cell Lymphotrophic virus type I or II infections. He had recurrent Candidiasis infection and his CD4 count was just 53 cells/mm³ after 3 months. The cause for the decline of CD4 T lymphocytes was unknown.

Criptococosis y linfocitopenia T CD4 idiopática: Reporte de un caso

La linfocitopenia T CD4 idiopática (LCI) es un síndrome clínico inusual que se caracteriza por un déficit de células T CD4+ circulantes en ausencia de infección por VIH u otra condición de inmunosupresión. Los pacientes con dicha enfermedad pueden presentarse asintomáticos o con infecciones oportunistas, las más frecuentes son por criptococo, micobacterias o virales como herpes zoster. Presentamos el caso de un hombre de 32 años, sin antecedentes, en quien se descartó infección por retrovirus, con recuento de linfocitos T CD4+ menor a 300 células/m3; se diagnosticó LCI posterior al diagnóstico de criptococomas cerebrales mediante hallazgos imagenológicos los cuales fueron congruentes con estudios microbiológicos.

Idiopathic CD4 Lymphocytopenia: Current Insights

Idiopathic CD4 lymphocytopenia is a condition characterized by low CD4 counts. It is rare and most of the information about this illness comes from case reports. Presentation is usually in the 4th decade of life with opportunistic infections, autoimmune disease or neoplasia. The pathophysiology of this condition is not well understood. Management revolves around treatment of the presenting condition and close follow-up of these patients. This review presents a narrative summary of the current literature on idiopathic CD4 lymphocytopenia.

Transiently antigen-primed B cells return to naive-like state in absence of T-cell help

The perspective that naive B-cell recognition of antigen in the absence of T-cell help causes cell death or anergy is supported by in vivo studies of B cells that are continuously exposed to self-antigens. However, intravital imaging suggests that early B-cell recognition of large foreign antigens may be transient. Whether B cells are tolerized or can be recruited into humoural immune responses following such encounters is not clear. Here we show that in the presence of T-cell help, single transient antigen acquisition is sufficient to recruit B cells into the germinal centre and induce memory and plasma cell responses. In the absence of T-cell help, transiently antigen-primed B cells do not undergo apoptosis in vivo; they return to quiescence and are recruited efficiently into humoural responses upon reacquisition of antigen and T-cell help.

Combined Action of Anti-CD4 Autoantibodies and Rheumatoid Factor in the Development of CD4 Lymphocytopenia in Rats Immunized with HIV-1 gp120

The development of immunodeficiency in HIV-infected patients is known to result from CD4⁺ lymphocyte depletion. Most CD4⁺ lymphocyte cells destined to die are not infected. The mechanism of HIV-uninfected cell death has not yet been fully elucidated. The aim of this study is to examine the role of anti-CD4 autoantibodies and physiological rheumatoid factor (RF) in the development of CD4⁺ lymphocytopenia. Immunization of Wistar rats with gp120 HIV-1 induces chronic production of anti-CD4 autoantibodies and decreases CD4⁺ lymphocytes in the blood. However, the anti-CD4 autoantibodies produced as part of the immune response to gp120 do not kill CD4⁺ cells directly. In rats producing anti-CD4 autoantibodies, a low level of peripheral CD4 lymphocytes is associated with high blood RF levels. The sera containing RF killed lymphocytes when the lymphocytes were pretreated with sera containing anti-CD4 autoantibodies. Thus, the death of CD4⁺ lymphocytes in rats immunized with gp120 is a result of the combined action of anti-CD4 autoantibodies and RF, and the action of these factors can be separated in time. The fact that two signals are needed for CD4⁺ lymphocyte death in HIV gp120-immunized rats does not contradict the hypothesis of the activation-induced death of uninfected CD4⁺ cells in HIV-infected humans.

Idiopathic CD4 lymphocytopenia with sensorimotor polyneuropathy

A, 21-years-old, male, presented with acute onset, gradually progressive, predominantly distal, symmetrical weakness of both upper and lower limbs with arreflexia. He had impaired sensations in glove and stocking distribution with distal gradient. He was found to have absolute CD4 + cell count of 188 cells/μL, absolute CD8 cell count, 532 cells/μL and CD4: CD8 ratio of 0.35. Electrophysiology revealed reduced to absent CMAP amplitude as well as SNAPs in various nerves of upper and lower limbs, along with normal conduction velocity and normal F wave latencies. Pattern evoked visual potentials were prolonged, on both sides, P100 being 130 ms, on right and 108 ms, on left side. In the follow up of 2 years, he showed spontaneous but gradual clinical improvement but his electrophysiological parameters as well as CD 4+ cells count did not show any significant improvement.

An unusual complication after interventional cardiology reveals and infrequent condition: Idiopathic CD4 deficiency

Herpes zoster (HZ) is of rare occurrence after interventional procedures with few events reported until now. A 74 year-old man with a past medical history of idiopathic thrombocytopenic purpura, splenectomy, autoimmune hemolytic anemia, and polymyalgia rheumatica developed HZ on the right median nerve 7 days after he underwent a coronariography for managing an acute coronary syndrome. He evolved with cutaneous dissemination and required intravenous acyclovir therapy. Laboratory evaluation disclosed a previously unknown idiophatic CD4 lymphocytopenia. HZ should be added to the list of complications after interventional cardiology and associated immunosuppressive factors ruled out.

Varicella Zoster Virus Necrotizing Retinitis in Two Patients with Idiopathic CD4 Lymphocytopenia

PURPOSE

Progressive outer retinal necrosis (PORN) associated with varicella zoster virus (VZV) is usually diagnosed in HIV positive or immunosuppressed patients. We report two cases of immunocompetent patients with necrotizing viral retinitis found to have idiopathic CD4 lymphocytopenia.

METHODS

Clinical presentation, examination, imaging, and laboratory testing of two patients with VZV retinitis are presented.

RESULTS

An HIV negative patient with history of herpes zoster presented with rapid loss of vision and examination consistent with PORN. PCR testing confirmed VZV. Lymphocytopenia was noted with a CD4 count of 25/mm(3). A second HIV negative patient presented with blurred vision and lid swelling and was found to have peripheral VZV retinitis confirmed by PCR. Laboratory workup revealed lymphocytopenia with a CD4 count of 133/mm(3).

CONCLUSIONS

VZV necrotizing retinitis classic for PORN can occur in HIV negative patients. Idiopathic CD4 lymphocytopenia should be considered healthy patients who develop ocular infections seen in the immunocompromised.

Idiopathic lymphocytopenia

PURPOSE OF REVIEW

Idiopathic CD4⁺ lymphocytopenia (ICL) is defined by the reduction of the main lymphocyte subtype in peripheral blood and CD4⁺ T cells below 300/μl in the absence of any secondary known causes of lymphopenia, including viral causes. The present review aims to state the latest available data on clinical, pathological and therapeutic aspects related to ICL, published from 1990 to 2014. The last observed clinical presentation and complications of ICL patients are described. The latest findings and possible mechanisms involved in the development of ICL features are included in the present review; however, pathogenesis of ICL has remained mainly obscured. Finally, recent therapeutic efforts considered in ICL patients are discussed.

RECENT FINDINGS

In spite of the serious complications ICL has on the patients' quality of life, data on clinical, etiopathological and therapeutic behavior for ICL are very limited. On one side, an abnormal blood cell count may be the sole presentation; however, occurrence of disseminated malignant tumors is not uncommon in patients. Recent findings highlight the role of cytokines, especially interleukin-2, on features such as phenotype severity and responsiveness of the condition to therapy. In addition, some studies have suggested that a defect in hematopoietic stem cells may be involved in disease progression, an idea that is supported by the success of bone marrow transplantation in acquiring persistent remissions in ICL patients.

SUMMARY

ICL is a hematologic condition of increasing importance due to its diverse clinical and pathological spectrum. Molecular studies have shown the presence of mutations involved in lymphocyte development as potential factors that may contribute to ICL occurrence. ICL patients could present either with common infections or really serious malignant conditions. The role of cytokines, especially interleukin-2, has emerged as one of the main possible mechanisms involved in clinical and pathological behavior of ICL. Today, the main therapeutic approaches are controlling life-threatening infections and underlying disorders along with efforts to cure ICL through rising CD4⁺ cell counts using cytokine interventions and transplantation.

[A case of cerebellar brainstem form of progressive multifocal leukoencephalopathy associated with idiopathic CD4+ lymphocytopenia]

A 77-year-old woman presented with a 6-month history of slowly progressive cerebellar ataxia. T2-weighted MRI showed high signal intensity in the left upper dorsal pons and bilateral middle cerebellar peduncles. JC virus (JCV) DNA was detected in cerebrospinal fluid (CSF). The patient had no HIV infection, collagen disease, or a history of immunosuppressive treatment, but she was found to have CD4+ lymphocytopenia. We made a diagnosis of cerebellar brainstem form of progressive multifocal leukoencephalopathy (PML) presenting as cerebellar ataxia, which was presumably associated with idiopathic CD4+ lymphocytopenia. Following the treatment with mefloquine, the patient slightly improved clinically and JCV-DNA became negative in CSF.

Severe Pneumocystis jirovecii pneumonia in an idiopathic CD4+ lymphocytopenia patient: case report and review of the literature

INTRODUCTION

When diagnosing Pneumocystis jirovecii pneumonia (PJP), the clinical suspicion must be confirmed by laboratory tests. PJP is rarely described in patients with idiopathic CD4⁺ lymphocytopenia (ICL), a rare T-cell deficiency of unknown origin with persistently low levels of CD4⁺ T-cells (<300 µl^-1 or <20 % of total lymphocytes) but repeated negative human immunodeficiency virus (HIV) tests. We retrospectively analysed a case of an ICL patient with severe PJP associated with multiple opportunistic infections (OIs). We also reviewed the literature since 1986.

CASE PRESENTATION

A laboratory-confirmed case of PJP associated with invasive candidiasis and cytomegalovirus infection was reported in an ICL patient. Despite early treatment, the patient died of respiratory failure under polymicrobial pneumonia. According to the literature, the mortality rate of ICL patients is 10.4 % (33/316). In ICL patients, the risk of OI is 83.2 % (263/316), with viral infections being the most prevalent (58.2 %, 184/316), followed by fungal infections (52.2 %, 165/316) and mycobacterial infections (15.5 %, 49/316). Dysimmunity is reported in 15.5 % (49/316) of ICL patients. Among the fungal infections, cryptococcal infections are the most prevalent (24.1 %, 76/316), followed by candidiasis (15.5 %, 49/316) and PJP (7.9 %, 25/316).

CONCLUSIONS

The high risk of OIs underlines the importance of more vigorous preventative actions in hospitals. The response to therapy and the detection of early relapse of PJP may be monitored by several laboratory tests including quantitative PCR. It is essential to treat the ICL and to follow the guidelines concerning therapy and prophylaxis of OIs as given to HIV patients.

Cryptococcal rib osteomyelitis as primary and only symptom of idiopathic CD4 penia

A 59-year old man with idiopathic CD4 lymphopenia presented with extensive disseminated Cryptococcus neoformans infection including a large rib cryptoccocoma, vertebral spondylitis and pleural empyema. Complete resection of the affected part of the rib was necessary after failure of initial antifungal treatment. The vertebral spondylitis has been successfully managed at 3 years of follow-up by continuous itraconazole treatment and regular MRI combined with leucocyte scintigraphy assessment.

Long-term parvovirus B19 infections with genetic drift after cord blood transplantation complicated by persistent CD4+ lymphocytopenia

A 5-month-old girl was diagnosed with Langerhans cell histiocytosis and received unrelated umbilical cord blood transplantation at the age of 14 months. After cord blood transplantation, CD4(+) lymphocytopenia from unknown causes was observed, and persistent infections with human parvovirus B19 (B19) occurred. We performed repeated longitudinal genetic analysis for B19, which revealed 6 nucleotide mutations in B19 nonstructural protein regions in the patient. The resulting changes of the nonstructural 1 structure may have altered antigenicity of the virus and could play a role in the pathogenesis of persistent infection under immunocompromised conditions.

Idiopathic CD4 lymphopenia associated with neuroinvasive West Nile disease: case report and review of the literature

Idiopathic CD4 lymphocytopenia is a very rare condition resulting in an immunodeficiency disorder that may or may not result in opportunistic infections. Since its description in the early 1990s, the reason for this immune deficiency has remained unclear. Its association with viral illnesses, such as West Nile virus infection, has yet to be described. We report a 26-year-old patient who presented with fever, ascending paralysis, and progressive weakness of the upper extremities. To our knowledge, this is the first case of neuroinvasive West Nile virus occurring in the context of a diagnosis of idiopathic CD4 lymphocytopenia.

Successful fludarabine-based hematopoietic stem cell transplantation in a pediatric patient with idiopathic CD4+ lymphocytopenia

Idiopathic CD4+ lymphocytopenia (ICL) is a rare immunodeficiency disease with severe CD4 T-cell depletion, leading to serious opportunistic infections. The optimal treatment of ICL has not been determined, especially in severe form of the disease. Here, we report an eight-yr-old girl with ICL who was successfully treated with fludarabine-based conditioning HSCT. To the best of our knowledge, this is the first pediatric ICL case that was treated by HSCT. Allogeneic HSCT with a reduced intensity condition (RIC) regimen may be a feasible and curative treatment option in ICL patients with recurrent life-threatening complications.

Motor Axonal Neuropathy Associated With Idiopathic CD4(+) T-Lymphocytopenia

Idiopathic CD4⁺ T-lymphocytopenia is a rare immune disorder characterized by an unexplained deficit of CD4⁺ T cells and results in various opportunistic infections. Herein, we report a case of new onset weakness in a 10-year-old boy secondary to motor axonal neuropathy associated with idiopathic CD4⁺ T-lymphocytopenia. The patient was referred to rehabilitation for an evaluation of progressive weakness involving all four limbs. A subsequent nerve conduction study and needle electromyography identified motor axonal neuropathy. At that time, laboratory studies specific to the differential diagnosis of motor axonal neuropathy were performed; however, the abnormality noted was a decreased CD4⁺ T-lymphocyte count. Motor axonal neuropathy represents an uncommon manifestation of idiopathic CD4⁺ T-lymphocytopenia and is probably associated with an underlying immune process.

Probable disseminated Mycobacterium abscessus subspecies bolletii infection in a patient with idiopathic CD4+ T lymphocytopenia: a case report

Introduction

Rapidly growing mycobacteria are opportunistic pathogens in patients with underlying risk factors. Mycobacterium abscessus subsp. bolletii is a newly recognized member of rapidly growing mycobacteria, isolated from respiratory tract and cutaneous infections.

Case presentation

We describe a case of chronic disseminated infection caused by M. abscessus subsp. bolletii in a 38-year-old Sri Lankan man with idiopathic CD4+ T lymphocytopenia. Idiopathic CD4+ T lymphocytopenia is a rare cause of immunodysfunction that, similar to human immunodeficiency virus infection, causes a depletion of CD4+ T lymphocytes. M. abscessus subsp. bolletii infection was diagnosed by culture isolation from two sputum samples.

Conclusions

To the best of our knowledge this is the first report of M. abscessus subsp. bolletii disseminated infection in a patient affected by idiopathic CD4+ T lymphocytopenia. In contrast to previous reports, the isolate of M. abscessus subsp. bolletii presented intermediate resistance to clarithromycin and was susceptible to cefoxitin and imipenem.

Unravelling fungal immunity through primary immune deficiencies

Fungal infections affect individuals with an impaired immune system and are on the increase, often with serious consequences. Recent studies in patients with primary immune deficiencies (PIDs) have led to important breakthroughs in our understanding of the different, mutually exclusive pathways underlying immunity to mucocutaneous as opposed to invasive fungal infections. Patients with defects affecting segments of innate (dectin-1, CARD9, IL12RB1) or adaptive immunity (interleukin (IL)17-F, IL-17 receptor, STAT1, STAT3, antibodies to Th-17 cytokines) that disrupt the Th-17 pathway, are unable to clear superficial Candida or Dermatophyte infections and suffer with chronic mucocutaneous candidiasis (CMC). Patients with defects affecting phagocyte function (oxidative killing, neutropenia) or a severely impaired immune system are at risk of developing invasive, often fatal fungal disease with Aspergillus, Candida, Cryptococcai and other fungi. PIDs are hugely beneficial in promoting our knowledge of fungal immunity and provide important contributions toward evidence-based diagnosis and improved patient care.

Defective T cell chemotaxis to sphingosine 1-phosphate and chemokine CCL21 in idiopathic T lymphocytopenia

T cell chemotaxis to sphingosine 1-phosphate (S1P) and the chemokines CCL21 and CCL5 was studied in ten adults with T lymphocytopenia, other immunological abnormalities (nine of ten), and frequent bacterial infections (seven of ten). Mean chemotactic responses to S1P of CD4 T cells from CD4 T lymphocytopenic patients and of CD8 T cells from CD8 T lymphocytopenic patients were significantly lower than those of healthy matched controls. Chemotaxis to CCL21 was lower than that of controls for CD4 T cells of three CD4 T lymphocytopenic patients and for CD8 T cells of three CD8 T lymphocytopenic patients, but none of the T cells of patients had diminished chemotaxis to CCL5. Defective T cell chemotactic responses to S1P and some chemokines may lead to subset-selective abnormal T cell trafficking and chronic T cell lymphocytopenia.

[CXCR4, a therapeutic target in rare immunodeficiencies?]

Currently, more than 200 primary immunodeficiency diseases have been discovered. In most cases, genetic defects affect the expression or the function of proteins involved in immune development and homeostasis. Some orphan immuno-hematological disorders are characterized by an abnormal leukocyte trafficking, a notion predictive of an anomaly of the chemokine/chemokine receptor system. In this review, we focus on recent advances in the characterization of dysfunctions of the CXCL12 (SDF-1)/CXCR4 signaling axis in two rare human immunodeficiencies, one associated with a loss of CXCR4 function, the Idiopathic CD4(+) T-cell Lymphocytopenia, and the other with a gain of CXCR4 function, the WHIM syndrome.

Difficulty diagnosing chronic cryptococcal meningitis in idiopathic CD4+ lymphocytopenia

A 64-year-old man with idiopathic CD4(+) lymphocytopenia developed cognitive impairment and gait ataxia with isolated obstructive hydrocephalus, which was fatal. Cerebrospinal fluid showed mild pleocytosis, but the etiology was not revealed by extensive analysis. At autopsy, inflammatory cells, CD8(+) lymphocytes and abundant macrophages but not CD4(+) lymphocytes were infiltrating the meninges at the base of the brain. Electron microscopy demonstrated that inflammation was caused by Cryptococcus neoformans, which was localized exclusively within macrophages, where it grew with budding. Our study suggests that, in idiopathic CD4(+) lymphocytopenia, macrophages can efficiently phagocytize but inefficiently digest C. neoformans, thus representing a vehicle of chronic intracellular infection.

Case study documenting the diagnosis of idiopathic CD4+ Lymphocytopenia in a patient with atypical fungal infection (disseminated blastomycosis) by FNA of adrenal mass

Idiopathic CD4+ lymphocytopenia, described in 1992 by the Centers for Disease Control, is characterized by persistent CD4+ lymphocytopenia (less than 300 cells per micro-liter) in nonimmunosuppressed, HIV negative individuals, who present with atypical infections. This rare though likely undiagnosed entity is associated with chronic disseminated forms of either fungal or bacterial infections in otherwise healthy adults. We report a case of a 59-year-old male with ring-enhancing brain lesions, bilateral adrenal masses, lung and vocal cord nodules, where the diagnosis of exclusion was metastatic malignancy. Fine needle aspiration (FNA) of the adrenal mass and a subsequent vocal cord biopsy confirmed chronic widely disseminated blastomycosis. Flow cytometric evaluation of peripheral blood documented persistent selective CD4+ lymphocytopenia with T8 (suppressor) T-Lymphocyte count within normal range. We believe that idiopathic CD4+ lymphocytopenia is an important etiologic factor to be considered for patients who present with mass lesions and are diagnosed by FNA with atypical fungal infections. We relate the diagnostic criteria for idiopathic CD4+ lymphocytopenia and the importance of providing on-site triage for FNA samples for fungal studies and correlation for flow cytometry.

Idiopathic CD4+ T-cell lymphocytopenia is associated with impaired membrane expression of the chemokine receptor CXCR4

Idiopathic CD4(+) T-cell lymphocytopenia (ICL) is a rare acquired T-cell immunodeficiency of unknown pathogenic basis. Six adults with ICL who developed opportunistic infections were investigated using extensive immunophenotyping analysis and functional evaluation of the chemokine receptor CXCR4. For all 6 patients studied, a profound defect in CXCR4 expression was detected at the surface of CD4(+) T lymphocytes, in association with an abnormal intracellular accumulation of CXCR4 and of its natural ligand, the chemokine CXCL12. For all patients studied, CD4(+) T-cell chemotactic response toward CXCL12 was decreased, whereas sensitivity to CXCL8 was preserved. CXCR4 recovery after ligand-induced endocytosis was impaired in ICL CD4(+) T cells. Upon in vitro addition of interleukin-2 (IL-2), membrane expression of CXCR4 returned to normal levels in 5 of 6 patients, whereas intracellular accumulation of CXCR4 and CXCL12 disappeared. Upon therapeutic administration of IL-2, CD4(+) T-cell count and membrane CXCR4 expression and function improved over time in 3 of 4 patients treated. Therefore, our data indicate that ICL is associated with defective surface expression of CXCR4, which may be reversed by IL-2.

Asymptomatic pulmonary nodules in a patient with early-stage breast cancer: Cryptococcus infection

In breast cancer patients, pulmonary nodules are frequently considered a metastatic disease or primary lung tumor. We report the case of a 53-year-old woman with early-stage breast cancer (T1micN0M0) presenting with asymptomatic pulmonary nodules in the left upper lobe at follow-up 6 years after she underwent a mastectomy. A presumptive diagnosis of pulmonary metastasis was made, and the patient underwent a video-assisted thoracoscopic lung biopsy. Pathology showed granulomatous inflammation with Cryptococcus infection. Subsequently, antifungal therapy was prescribed, and full recovery followed. We demonstrate the importance of differentiating between pulmonary Cryptococcus infection and metastasis in breast cancer patients for correct management. The relationship between pulmonary Cryptococcus infection and breast cancer is also discussed.